diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 5486bd0c..5df301b9 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,257 +1,31 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2017-11-27 22:40:12 +0530 using RuboCop version 0.51.0.
+# on 2018-04-04 10:16:39 -0700 using RuboCop version 0.54.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 1
+# Offense count: 8
 # Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: with_first_parameter, with_fixed_indentation
-Layout/AlignParameters:
-  Exclude:
-    - 'Vagrantfile'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-Layout/ClosingParenthesisIndentation:
-  Exclude:
-    - 'app/controllers/conference_registrations_controller.rb'
-    - 'spec/support/omniauth_macros.rb'
-
-# Offense count: 14
-# Cop supports --auto-correct.
-Layout/CommentIndentation:
-  Exclude:
-    - 'app/controllers/admin/comments_controller.rb'
-    - 'app/controllers/admin/difficulty_levels_controller.rb'
-    - 'app/models/conference.rb'
-    - 'app/models/program.rb'
-    - 'app/models/track.rb'
-    - 'spec/features/volunteers_spec.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Layout/EmptyLineAfterMagicComment:
-  Exclude:
-    - 'spec/models/conference_spec.rb'
-
-# Offense count: 109
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: empty_lines, no_empty_lines
-Layout/EmptyLinesAroundBlockBody:
-  Enabled: false
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Layout/EmptyLinesAroundExceptionHandlingKeywords:
-  Exclude:
-    - 'app/models/payment.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: AllowForAlignment, ForceEqualSignAlignment.
-Layout/ExtraSpacing:
-  Exclude:
-    - 'Guardfile'
-    - 'app/controllers/application_controller.rb'
-    - 'config.ru'
-    - 'db/migrate/20140623101032_create_ahoy_events.rb'
-    - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
-    - 'db/migrate/20140719160903_create_delayed_jobs.rb'
-    - 'spec/models/conference_spec.rb'
-
-# Offense count: 42
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: consistent, special_for_inner_method_call, special_for_inner_method_call_in_parentheses
-Layout/FirstParameterIndentation:
-  Enabled: false
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: special_inside_parentheses, consistent, align_brackets
-Layout/IndentArray:
-  Exclude:
-    - 'app/models/conference.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: IndentationWidth.
-Layout/IndentAssignment:
-  Exclude:
-    - 'app/helpers/format_helper.rb'
-    - 'app/models/conference.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: special_inside_parentheses, consistent, align_braces
-Layout/IndentHash:
+# Configuration parameters: EnforcedHashRocketStyle, EnforcedColonStyle, EnforcedLastArgumentHashStyle.
+# SupportedHashRocketStyles: key, separator, table
+# SupportedColonStyles: key, separator, table
+# SupportedLastArgumentHashStyles: always_inspect, always_ignore, ignore_implicit, ignore_explicit
+Layout/AlignHash:
   Exclude:
     - 'app/models/user.rb'
-    - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: normal, rails
-Layout/IndentationConsistency:
-  Exclude:
-    - 'app/controllers/users_controller.rb'
-    - 'app/models/event.rb'
-    - 'spec/controllers/subscriptions_controller_spec.rb'
-
-# Offense count: 4
-# Cop supports --auto-correct.
-Layout/LeadingCommentSpace:
-  Exclude:
-    - 'Guardfile'
-    - 'app/models/comment.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: symmetrical, new_line, same_line
-Layout/MultilineArrayBraceLayout:
-  Exclude:
-    - 'app/controllers/conference_registrations_controller.rb'
+    - 'spec/mailers/mailbot_spec.rb'
 
 # Offense count: 5
 # Cop supports --auto-correct.
-Layout/MultilineBlockLayout:
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: with_first_parameter, with_fixed_indentation
+Layout/AlignParameters:
   Exclude:
-    - 'app/serializers/conference_serializer.rb'
-
-# Offense count: 6
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: symmetrical, new_line, same_line
-Layout/MultilineHashBraceLayout:
-  Exclude:
-    - 'app/serializers/conference_serializer.rb'
-    - 'spec/models/event_spec.rb'
-
-# Offense count: 40
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: symmetrical, new_line, same_line
-Layout/MultilineMethodCallBraceLayout:
-  Enabled: false
-
-# Offense count: 53
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: aligned, indented, indented_relative_to_receiver
-Layout/MultilineMethodCallIndentation:
-  Enabled: false
-
-# Offense count: 23
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, IndentationWidth.
-# SupportedStyles: aligned, indented
-Layout/MultilineOperationIndentation:
-  Exclude:
-    - 'app/controllers/application_controller.rb'
-    - 'app/models/conference.rb'
-    - 'app/models/event.rb'
-    - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Layout/SpaceAfterComma:
-  Exclude:
-    - 'lib/tasks/data_demo.rake'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: space, no_space
-Layout/SpaceAroundEqualsInParameterDefault:
-  Exclude:
-    - 'app/helpers/format_helper.rb'
-    - 'app/models/event.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: AllowForAlignment.
-Layout/SpaceAroundOperators:
-  Exclude:
-    - 'lib/tasks/data.rake'
-
-# Offense count: 463
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, SupportedStylesForEmptyBraces.
-# SupportedStyles: space, no_space
-# SupportedStylesForEmptyBraces: space, no_space
-Layout/SpaceBeforeBlockBraces:
-  Enabled: false
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Layout/SpaceBeforeComma:
-  Exclude:
-    - 'lib/tasks/data_demo.rake'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Layout/SpaceBeforeSemicolon:
-  Exclude:
-    - 'Guardfile'
-
-# Offense count: 54
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, EnforcedStyleForEmptyBraces, SupportedStylesForEmptyBraces, SpaceBeforeBlockParameters.
-# SupportedStyles: space, no_space
-# SupportedStylesForEmptyBraces: space, no_space
-Layout/SpaceInsideBlockBraces:
-  Exclude:
-    - 'app/controllers/admin/comments_controller.rb'
-    - 'app/controllers/admin/questions_controller.rb'
-    - 'app/helpers/application_helper.rb'
-    - 'app/models/program.rb'
-    - 'app/models/ticket.rb'
-    - 'app/models/user.rb'
-    - 'lib/tasks/events_registrations.rake'
-    - 'spec/controllers/admin/event_schedules_controller_spec.rb'
-    - 'spec/controllers/admin/schedules_controller_spec.rb'
-    - 'spec/features/splashpage_spec.rb'
-    - 'spec/models/ability_spec.rb'
-    - 'spec/models/user_spec.rb'
-
-# Offense count: 19
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, EnforcedStyleForEmptyBraces, SupportedStylesForEmptyBraces.
-# SupportedStyles: space, no_space, compact
-# SupportedStylesForEmptyBraces: space, no_space
-Layout/SpaceInsideHashLiteralBraces:
-  Exclude:
-    - 'app/controllers/admin/conferences_controller.rb'
-    - 'app/controllers/api/v1/speakers_controller.rb'
-    - 'app/models/conference.rb'
-    - 'app/models/event_type.rb'
-    - 'app/models/user.rb'
-    - 'spec/models/event_spec.rb'
-    - 'spec/models/payment_spec.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-Layout/SpaceInsidePercentLiteralDelimiters:
-  Exclude:
-    - 'Gemfile'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: final_newline, final_blank_line
-Layout/TrailingBlankLines:
-  Exclude:
-    - 'lib/tasks/event_attatchments.rake'
-    - 'lib/tasks/roles.rake'
+    - 'spec/controllers/admin/conferences_controller_spec.rb'
+    - 'spec/controllers/admin/registration_periods_controller_spec.rb'
+    - 'spec/models/email_settings_spec.rb'
 
 # Offense count: 13
 Lint/AmbiguousBlockAssociation:
@@ -276,60 +50,34 @@ Lint/IneffectiveAccessModifier:
     - 'app/models/commercial.rb'
     - 'app/models/conference.rb'
 
-# Offense count: 2
-Lint/RescueWithoutErrorClass:
-  Exclude:
-    - 'app/controllers/users/omniauth_callbacks_controller.rb'
-    - 'lib/tasks/migrate_config.rake'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-Lint/ScriptPermission:
-  Exclude:
-    - 'Guardfile'
-    - 'Rakefile'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: IgnoreEmptyBlocks, AllowUnusedKeywordArguments.
-Lint/UnusedBlockArgument:
-  Exclude:
-    - 'lib/tasks/user.rake'
-
-# Offense count: 136
+# Offense count: 140
 Metrics/AbcSize:
-  Max: 98
+  Max: 94
 
-# Offense count: 258
+# Offense count: 310
 # Configuration parameters: CountComments, ExcludedMethods.
 Metrics/BlockLength:
-  Max: 471
+  Max: 1420
 
-# Offense count: 28
+# Offense count: 32
 Metrics/CyclomaticComplexity:
   Max: 14
 
-# Offense count: 2774
-# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
-# URISchemes: http, https
-Metrics/LineLength:
-  Max: 619
-
-# Offense count: 133
+# Offense count: 136
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
-  Max: 63
+  Max: 60
 
-# Offense count: 4
+# Offense count: 5
 # Configuration parameters: CountComments.
 Metrics/ModuleLength:
-  Max: 200
+  Max: 180
 
-# Offense count: 20
+# Offense count: 22
 Metrics/PerceivedComplexity:
   Max: 16
 
-# Offense count: 20
+# Offense count: 18
 Naming/AccessorMethodName:
   Exclude:
     - 'app/controllers/application_controller.rb'
@@ -367,44 +115,268 @@ Naming/PredicateName:
     - 'app/models/contact.rb'
 
 # Offense count: 2
-# Configuration parameters: EnforcedStyle, SupportedStyles.
+# Configuration parameters: MinNameLength, AllowNamesEndingInNumbers, AllowedNames, ForbiddenNames.
+# AllowedNames: io, id, to
+Naming/UncommunicativeMethodParamName:
+  Exclude:
+    - 'app/models/conference.rb'
+
+# Offense count: 2
+# Configuration parameters: EnforcedStyle.
 # SupportedStyles: snake_case, normalcase, non_integer
 Naming/VariableNumber:
   Exclude:
     - 'spec/models/ticket_purchase_spec.rb'
 
-
 # Offense count: 1
 # Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: is_a?, kind_of?
-Style/ClassCheck:
+# Configuration parameters: EnforcedStyle, Include.
+# SupportedStyles: action, filter
+# Include: app/controllers/**/*.rb
+Rails/ActionFilter:
   Exclude:
+    - 'app/controllers/users/omniauth_callbacks_controller.rb'
+
+# Offense count: 103
+# Cop supports --auto-correct.
+Rails/ActiveRecordAliases:
+  Enabled: false
+
+# Offense count: 124
+# Cop supports --auto-correct.
+Rails/ApplicationRecord:
+  Enabled: false
+
+# Offense count: 11
+# Cop supports --auto-correct.
+# Configuration parameters: NilOrEmpty, NotPresent, UnlessPresent.
+Rails/Blank:
+  Exclude:
+    - 'app/controllers/conferences_controller.rb'
+    - 'app/controllers/users/omniauth_callbacks_controller.rb'
+    - 'app/models/program.rb'
+    - 'app/models/user.rb'
+    - 'db/migrate/20160309182655_remove_dietary_choices_table.rb'
+    - 'spec/factories/event_schedule.rb'
+
+# Offense count: 19
+# Configuration parameters: Include.
+# Include: db/migrate/*.rb
+Rails/CreateTableWithTimestamps:
+  Enabled: false
+
+# Offense count: 126
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: strict, flexible
+Rails/Date:
+  Enabled: false
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: EnforceForPrefixed.
+Rails/Delegate:
+  Exclude:
+    - 'app/models/event.rb'
+    - 'app/models/room.rb'
+    - 'app/models/track.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+# Configuration parameters: Whitelist.
+# Whitelist: find_by_sql
+Rails/DynamicFindBy:
+  Exclude:
+    - 'app/controllers/admin/events_controller.rb'
+    - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
+
+# Offense count: 5
+Rails/FilePath:
+  Exclude:
+    - 'app/pdfs/ticket_pdf.rb'
+    - 'spec/features/lodgings_spec.rb'
+    - 'spec/features/sponsor_spec.rb'
+    - 'spec/spec_helper.rb'
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/FindBy:
+  Exclude:
+    - 'app/models/event.rb'
+    - 'app/models/openid.rb'
+    - 'app/models/ticket_purchase.rb'
+    - 'app/models/user.rb'
+
+# Offense count: 6
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/HasAndBelongsToMany:
+  Exclude:
+    - 'app/models/conference.rb'
+    - 'app/models/qanswer.rb'
+    - 'app/models/question.rb'
+    - 'app/models/registration.rb'
+    - 'app/models/vchoice.rb'
+
+# Offense count: 18
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/HasManyOrHasOneDependent:
+  Exclude:
+    - 'app/models/answer.rb'
+    - 'app/models/event.rb'
+    - 'app/models/payment.rb'
+    - 'app/models/physical_ticket.rb'
+    - 'app/models/question_type.rb'
+    - 'app/models/registration.rb'
+    - 'app/models/role.rb'
+    - 'app/models/room.rb'
+    - 'app/models/sponsorship_level.rb'
+    - 'app/models/ticket_purchase.rb'
+    - 'app/models/track.rb'
+    - 'app/models/user.rb'
+    - 'app/models/vday.rb'
+    - 'app/models/visit.rb'
+    - 'app/models/vposition.rb'
+
+# Offense count: 254
+# Cop supports --auto-correct.
+# Configuration parameters: Include.
+# Include: spec/**/*, test/**/*
+Rails/HttpPositionalArguments:
+  Enabled: false
+
+# Offense count: 8
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: numeric, symbolic
+Rails/HttpStatus:
+  Exclude:
+    - 'app/controllers/admin/commercials_controller.rb'
+    - 'app/controllers/admin/event_schedules_controller.rb'
+    - 'app/controllers/admin/programs_controller.rb'
+    - 'app/controllers/admin/tracks_controller.rb'
+    - 'app/controllers/admin/venue_commercials_controller.rb'
+    - 'app/controllers/commercials_controller.rb'
+
+# Offense count: 14
+# Configuration parameters: Include.
+# Include: app/models/**/*.rb
+Rails/InverseOf:
+  Exclude:
+    - 'app/models/booth.rb'
+    - 'app/models/conference.rb'
+    - 'app/models/event.rb'
+    - 'app/models/program.rb'
+    - 'app/models/track.rb'
+    - 'app/models/user.rb'
+    - 'app/models/venue.rb'
+    - 'app/models/visit.rb'
+
+# Offense count: 1
+# Configuration parameters: Include.
+# Include: app/controllers/**/*.rb
+Rails/LexicallyScopedActionFilter:
+  Exclude:
+    - 'app/controllers/registrations_controller.rb'
+
+# Offense count: 4
+Rails/OutputSafety:
+  Exclude:
+    - 'app/helpers/events_helper.rb'
+    - 'app/helpers/format_helper.rb'
+    - 'app/models/commercial.rb'
+
+# Offense count: 15
+# Cop supports --auto-correct.
+Rails/PluralizationGrammar:
+  Exclude:
+    - 'spec/models/conference_spec.rb'
+
+# Offense count: 5
+# Cop supports --auto-correct.
+Rails/Presence:
+  Exclude:
+    - 'app/controllers/schedules_controller.rb'
+    - 'app/helpers/application_helper.rb'
+    - 'app/models/user.rb'
+    - 'db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb'
+
+# Offense count: 23
+# Cop supports --auto-correct.
+# Configuration parameters: NotNilAndNotEmpty, NotBlank, UnlessBlank.
+Rails/Present:
+  Exclude:
+    - 'app/helpers/users_helper.rb'
+    - 'app/models/campaign.rb'
+    - 'app/models/cfp.rb'
     - 'app/models/email_settings.rb'
+    - 'app/models/event.rb'
+    - 'app/models/program.rb'
+    - 'app/models/venue.rb'
+    - 'db/migrate/20141104131625_generate_username.rb'
+
+# Offense count: 52
+# Configuration parameters: Include.
+# Include: db/migrate/*.rb
+Rails/ReversibleMigration:
+  Exclude:
+    - 'db/migrate/20140530082708_remove_color_defaults.rb'
+    - 'db/migrate/20140605125153_update_event_states.rb'
+    - 'db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb'
+    - 'db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb'
+    - 'db/migrate/20140623150541_drop_person_and_event_person_tables.rb'
+    - 'db/migrate/20140731165107_move_conference_contact_details_to_contact.rb'
+    - 'db/migrate/20140801164901_move_conference_media_to_commercial.rb'
+    - 'db/migrate/20140801170430_move_event_media_to_commercial.rb'
+    - 'db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb'
+    - 'db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb'
+    - 'db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb'
+    - 'db/migrate/20140930092923_move_sponsor_email_to_contact.rb'
+    - 'db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb'
+    - 'db/migrate/20141130182139_drop_table_event_attachments.rb'
+
+# Offense count: 8
+# Configuration parameters: Blacklist.
+# Blacklist: decrement!, decrement_counter, increment!, increment_counter, toggle!, touch, update_all, update_attribute, update_column, update_columns, update_counters
+Rails/SkipsModelValidations:
+  Exclude:
+    - 'app/models/concerns/revision_count.rb'
+    - 'db/migrate/20140730104658_migrate_roles_for_cancancan.rb'
+    - 'db/migrate/20161229080315_add_comments_count_to_events.rb'
+    - 'db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb'
+    - 'db/migrate/20180313012253_add_timestamps_to_tickets.rb'
+    - 'lib/tasks/user.rake'
+    - 'spec/controllers/conferences_controller_spec.rb'
+
+# Offense count: 50
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: strict, flexible
+Rails/TimeZone:
+  Exclude:
+    - 'app/models/comment.rb'
+    - 'app/models/conference.rb'
+    - 'db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb'
+    - 'db/migrate/20180313012253_add_timestamps_to_tickets.rb'
+    - 'lib/tasks/dump_db.rake'
+    - 'spec/controllers/admin/comments_controller_spec.rb'
+    - 'spec/controllers/admin/programs_controller_spec.rb'
+    - 'spec/factories/users.rb'
+    - 'spec/models/campaign_spec.rb'
+    - 'spec/models/conference_spec.rb'
+
+# Offense count: 2
+Security/Open:
+  Exclude:
+    - 'app/pdfs/ticket_pdf.rb'
 
 # Offense count: 1
 Style/ClassVars:
   Exclude:
     - 'spec/support/kneet_connections.rb'
 
-# Offense count: 2
-# Cop supports --auto-correct.
-Style/ColonMethodCall:
-  Exclude:
-    - 'app/models/commercial.rb'
-    - 'app/models/contact.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, SingleLineConditionsOnly, IncludeTernaryExpressions.
-# SupportedStyles: assign_to_condition, assign_inside_condition
-Style/ConditionalAssignment:
-  Exclude:
-    - 'app/helpers/format_helper.rb'
-    - 'db/migrate/20140610165551_migrate_data_person_to_user.rb'
-    - 'db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb'
-
-# Offense count: 9
+# Offense count: 11
 Style/DateTime:
   Exclude:
     - 'app/models/conference.rb'
@@ -412,301 +384,66 @@ Style/DateTime:
     - 'spec/models/conference_spec.rb'
     - 'spec/models/program_spec.rb'
 
-# Offense count: 488
+# Offense count: 495
 Style/Documentation:
   Enabled: false
 
-# Offense count: 2
-# Cop supports --auto-correct.
-Style/EmptyCaseCondition:
-  Exclude:
-    - 'app/helpers/format_helper.rb'
-    - 'app/helpers/versions_helper.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Style/EmptyLiteral:
-  Exclude:
-    - 'spec/models/conference_spec.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: compact, expanded
-Style/EmptyMethod:
-  Exclude:
-    - 'app/controllers/admin/lodgings_controller.rb'
-    - 'app/controllers/admin/registration_periods_controller.rb'
-    - 'app/controllers/users_controller.rb'
-    - 'db/migrate/20121223115125_create_tracks_table.rb'
-    - 'db/migrate/20121223115135_create_events_table.rb'
-    - 'db/migrate/20130103134212_create_registrations_table.rb'
-    - 'db/migrate/20130206192339_rename_attending_social_events_with_partner.rb'
-    - 'db/migrate/20130216122155_set_registration_defaults_to_false.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-Style/Encoding:
-  Exclude:
-    - 'app/uploaders/picture_uploader.rb'
-    - 'spec/models/conference_spec.rb'
-
-# Offense count: 32
+# Offense count: 20
 # Configuration parameters: MinBodyLength.
 Style/GuardClause:
-  Enabled: false
-
-# Offense count: 4
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, UseHashRocketsWithSymbolValues, PreferHashRocketsForNonAlnumEndingSymbols.
-# SupportedStyles: ruby19, hash_rockets, no_mixed_keys, ruby19_no_mixed_keys
-Style/HashSyntax:
   Exclude:
-    - 'Gemfile'
-    - 'lib/tasks/user.rake'
-
-# Offense count: 22
-# Cop supports --auto-correct.
-# Configuration parameters: MaxLineLength.
-Style/IfUnlessModifier:
-  Exclude:
-    - 'app/controllers/api/v1/events_controller.rb'
+    - 'app/controllers/admin/organizations_controller.rb'
     - 'app/controllers/conference_registrations_controller.rb'
-    - 'app/controllers/users/omniauth_callbacks_controller.rb'
-    - 'app/helpers/application_helper.rb'
-    - 'app/models/commercial.rb'
-    - 'app/models/conference.rb'
-    - 'app/models/email_settings.rb'
-    - 'app/models/user.rb'
-    - 'db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb'
-    - 'lib/tasks/events_registrations.rake'
-    - 'spec/controllers/admin/conferences_controller_spec.rb'
-    - 'spec/support/flash.rb'
-
-# Offense count: 8
-# Cop supports --auto-correct.
-Style/LineEndConcatenation:
-  Exclude:
-    - 'spec/features/cfp_spec.rb'
-    - 'spec/features/conference_spec.rb'
-    - 'spec/features/registration_periods_spec.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: require_parentheses, require_no_parentheses, require_no_parentheses_except_multiline
-Style/MethodDefParentheses:
-  Exclude:
-    - 'app/models/conference.rb'
-    - 'app/models/user.rb'
-    - 'lib/tasks/demo_data_for_development.rake'
-
-# Offense count: 7
-# Cop supports --auto-correct.
-Style/MultilineIfModifier:
-  Exclude:
     - 'app/controllers/conferences_controller.rb'
+    - 'app/controllers/registrations_controller.rb'
     - 'app/controllers/schedules_controller.rb'
+    - 'app/helpers/events_helper.rb'
+    - 'app/models/ability.rb'
     - 'app/models/cfp.rb'
-    - 'app/models/event.rb'
+    - 'app/models/conference.rb'
+    - 'app/models/registration.rb'
     - 'app/models/registration_period.rb'
+    - 'app/models/user.rb'
+    - 'db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb'
+    - 'lib/tasks/data.rake'
 
-# Offense count: 2
+# Offense count: 37
 # Cop supports --auto-correct.
-Style/MutableConstant:
-  Exclude:
-    - 'app/models/event_user.rb'
-    - 'lib/tasks/migrate_config.rake'
-
-# Offense count: 4
-# Cop supports --auto-correct.
-# Configuration parameters: Whitelist.
-# Whitelist: be, be_a, be_an, be_between, be_falsey, be_kind_of, be_instance_of, be_truthy, be_within, eq, eql, end_with, include, match, raise_error, respond_to, start_with
-Style/NestedParenthesizedCalls:
-  Exclude:
-    - 'spec/features/conference_spec.rb'
-    - 'spec/models/conference_spec.rb'
-
-# Offense count: 27
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, MinBodyLength, SupportedStyles.
-# SupportedStyles: skip_modifier_ifs, always
-Style/Next:
+Style/IfUnlessModifier:
   Enabled: false
 
-# Offense count: 117
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedOctalStyle, SupportedOctalStyles.
-# SupportedOctalStyles: zero_with_o, zero_only
-Style/NumericLiteralPrefix:
+# Offense count: 1
+Style/MixinUsage:
   Exclude:
-    - 'spec/controllers/admin/conferences_controller_spec.rb'
-    - 'spec/controllers/conference_registration_controller_spec.rb'
-    - 'spec/helpers/date_time_helper_spec.rb'
-    - 'spec/models/conference_spec.rb'
-    - 'spec/models/email_settings_spec.rb'
-    - 'spec/models/registration_spec.rb'
-    - 'spec/serializers/conference_serializer_spec.rb'
-    - 'spec/serializers/event_serializer_spec.rb'
+    - 'spec/spec_helper.rb'
 
-# Offense count: 7
+# Offense count: 41
 # Cop supports --auto-correct.
-# Configuration parameters: Strict.
-Style/NumericLiterals:
-  MinDigits: 15
-
-# Offense count: 7
-# Cop supports --auto-correct.
-# Configuration parameters: AutoCorrect, EnforcedStyle, SupportedStyles.
+# Configuration parameters: AutoCorrect, EnforcedStyle.
 # SupportedStyles: predicate, comparison
 Style/NumericPredicate:
   Exclude:
     - 'spec/**/*'
     - 'app/controllers/admin/conferences_controller.rb'
+    - 'app/helpers/application_helper.rb'
     - 'app/helpers/date_time_helper.rb'
     - 'app/helpers/format_helper.rb'
+    - 'app/models/cfp.rb'
+    - 'app/models/conference.rb'
+    - 'app/models/event.rb'
+    - 'app/models/program.rb'
+    - 'app/models/registration.rb'
+    - 'app/models/ticket_purchase.rb'
     - 'app/models/user.rb'
+    - 'lib/tasks/events_registrations.rake'
 
 # Offense count: 3
 Style/OptionalArguments:
   Exclude:
     - 'app/models/event.rb'
 
-# Offense count: 1
-# Cop supports --auto-correct.
-Style/OrAssignment:
-  Exclude:
-    - 'app/controllers/schedules_controller.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: AllowSafeAssignment.
-Style/ParenthesesAroundCondition:
-  Exclude:
-    - 'app/controllers/admin/base_controller.rb'
-    - 'app/controllers/application_controller.rb'
-    - 'app/helpers/format_helper.rb'
-
-# Offense count: 15
-# Cop supports --auto-correct.
-# Configuration parameters: PreferredDelimiters.
-Style/PercentLiteralDelimiters:
-  Exclude:
-    - 'Gemfile'
-    - 'app/controllers/admin/users_controller.rb'
-    - 'app/models/cfp.rb'
-    - 'app/models/comment.rb'
-    - 'app/models/commercial.rb'
-    - 'app/models/conference.rb'
-    - 'app/models/contact.rb'
-    - 'app/models/registration.rb'
-    - 'app/models/subscription.rb'
-    - 'app/models/track.rb'
-    - 'app/uploaders/picture_uploader.rb'
-    - 'spec/models/program_spec.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: short, verbose
-Style/PreferredHashMethods:
-  Exclude:
-    - 'lib/tasks/migrate_config.rake'
-
-# Offense count: 6
-# Cop supports --auto-correct.
-# Configuration parameters: SupportedStyles.
-# SupportedStyles: compact, exploded
-Style/RaiseArgs:
-  EnforcedStyle: compact
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Style/RedundantParentheses:
-  Exclude:
-    - 'app/controllers/admin/base_controller.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, AllowInnerSlashes.
-# SupportedStyles: slashes, percent_r, mixed
-Style/RegexpLiteral:
-  Exclude:
-    - 'Guardfile'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: only_raise, only_fail, semantic
-Style/SignalException:
-  Exclude:
-    - 'lib/tasks/user.rake'
-    - 'spec/support/flash.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: AllowIfMethodIsEmpty.
-Style/SingleLineMethods:
-  Exclude:
-    - 'Guardfile'
-
-# Offense count: 16
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, ConsistentQuotesInMultiline.
-# SupportedStyles: single_quotes, double_quotes
-Style/StringLiterals:
-  Exclude:
-    - 'Gemfile'
-    - 'Vagrantfile'
-    - 'lib/tasks/dump_db.rake'
-    - 'lib/tasks/events_registrations.rake'
-    - 'lib/tasks/factory_girl.rake'
-    - 'lib/tasks/user.rake'
-
-# Offense count: 6
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: single_quotes, double_quotes
-Style/StringLiteralsInInterpolation:
-  Exclude:
-    - 'lib/tasks/dump_db.rake'
-
-# Offense count: 79
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, MinSize, SupportedStyles.
-# SupportedStyles: percent, brackets
-Style/SymbolArray:
-  Enabled: false
-
-# Offense count: 11
-# Cop supports --auto-correct.
-# Configuration parameters: IgnoredMethods.
-# IgnoredMethods: respond_to, define_method
-Style/SymbolProc:
-  Exclude:
-    - 'app/controllers/admin/comments_controller.rb'
-    - 'app/controllers/admin/questions_controller.rb'
-    - 'app/helpers/application_helper.rb'
-    - 'app/models/ability.rb'
-    - 'app/models/admin_ability.rb'
-    - 'db/migrate/20140730104658_migrate_roles_for_cancancan.rb'
-    - 'spec/controllers/admin/conferences_controller_spec.rb'
-    - 'spec/support/flash.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, AllowSafeAssignment.
-# SupportedStyles: require_parentheses, require_no_parentheses, require_parentheses_when_complex
-Style/TernaryParentheses:
-  Exclude:
-    - 'app/helpers/format_helper.rb'
-
-# Offense count: 23
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyleForMultiline, SupportedStylesForMultiline.
-# SupportedStylesForMultiline: comma, consistent_comma, no_comma
-Style/TrailingCommaInLiteral:
-  Exclude:
-    - 'Guardfile'
-    - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
-    - 'spec/models/conference_spec.rb'
+# Offense count: 2835
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 619
diff --git a/Gemfile b/Gemfile
index 69610b57..9399694a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,9 +1,9 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 # rails-assets requires >= 1.8.4
-if Gem::Version.new(Bundler::VERSION) < Gem::Version.new('1.8.4')
-  abort "Bundler version >= 1.8.4 is required"
-end
+abort 'Bundler version >= 1.8.4 is required' if Gem::Version.new(Bundler::VERSION) < Gem::Version.new('1.8.4')
 
 # as web framework
 gem 'rails', '~> 5.0.5'
@@ -60,7 +60,7 @@ gem 'rolify'
 gem 'unobtrusive_flash', '>=3'
 
 # as state machine
-gem 'transitions', :require => %w( transitions active_record/transitions )
+gem 'transitions', require: %w[transitions active_record/transitions]
 
 # for comments
 gem 'acts_as_commentable_with_threading'
@@ -164,7 +164,7 @@ gem 'piwik_analytics', '~> 1.0.1'
 
 # for recurring jobs
 gem 'delayed_job_active_record'
-gem 'whenever', :require => false
+gem 'whenever', require: false
 
 # to run scripts
 gem 'daemons'
@@ -192,7 +192,7 @@ gem 'dotenv-rails'
 gem 'feature'
 
 # For countable.js
-gem "countable-rails", "~> 0.0.1"
+gem 'countable-rails', '~> 0.0.1'
 
 # Both are not in a group as we use it also for rake data:demo
 # for fake data
@@ -244,7 +244,7 @@ group :test do
   # as test framework
   gem 'capybara'
   gem 'database_cleaner'
-  gem 'phantomjs', :require => 'phantomjs/poltergeist'
+  gem 'phantomjs', require: 'phantomjs/poltergeist'
   gem 'poltergeist'
   gem 'rspec-rails', '~> 3.5', '>= 3.5.2'
   # for measuring test coverage
diff --git a/Guardfile b/Guardfile
old mode 100644
new mode 100755
index 3f92b1a3..29f435ff
--- a/Guardfile
+++ b/Guardfile
@@ -1,4 +1,6 @@
 #!/usr/bin/ruby
+# frozen_string_literal: true
+
 #
 # More info at https://github.com/guard/guard#readme
 
@@ -8,7 +10,9 @@ guard_opts = {
   cmd: 'spring rspec'
 }
 
-def model_specs       ; 'spec/models'       end
+def model_specs
+  'spec/models'
+end
 
 def model_spec(model)
   "spec/models/#{model}_spec.rb"
@@ -19,19 +23,19 @@ def all_testunit_tests
     model_tests,
     controller_tests,
     helper_tests,
-    integration_tests,
+    integration_tests
   ]
 end
 
 def all_specs
   [
-    model_specs,
+    model_specs
   ]
 end
 
 def startup_guards
-  watch(%r{^Gemfile$})                      { yield }
-  watch(%r{^Gemfile.lock$})                 { yield }
+  watch(/^Gemfile$/)                      { yield }
+  watch(/^Gemfile.lock$/)                 { yield }
   watch(%r{^config/routes.rb$})             { yield }
   watch(%r{^config/application\.rb$})       { yield }
   watch(%r{^config/environment\.rb$})       { yield }
@@ -44,14 +48,14 @@ end
 def rspec_guards
   watch(%r{^spec/factories/.+\.rb$})        { all_specs }
   watch(%r{^spec/.+_spec\.rb$})
-  watch(%r{^app/(.+)\.rb$})                 { |m| "spec/#{m[1]}_spec.rb" }
+  watch(%r{^app/(.+)\.rb$}) { |m| "spec/#{m[1]}_spec.rb" }
 end
 
 group :rspec do
   guard 'rspec', guard_opts do
-    #startup_guards { all_specs }
+    # startup_guards { all_specs }
     rspec_guards
-    #all_specs
+    # all_specs
   end
 end
 
diff --git a/Rakefile b/Rakefile
old mode 100644
new mode 100755
index f29eb6f1..407636a7
--- a/Rakefile
+++ b/Rakefile
@@ -1,7 +1,9 @@
 #!/usr/bin/env rake
+# frozen_string_literal: true
+
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require File.expand_path('../config/application', __FILE__)
+require File.expand_path('config/application', __dir__)
 
 Osem::Application.load_tasks
diff --git a/Vagrantfile b/Vagrantfile
index bf3622e4..8e3c3868 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # -*- mode: ruby -*-
 # vi: set ft=ruby :
 
@@ -12,7 +14,7 @@ Vagrant.configure(2) do |config|
 
   # Every Vagrant development environment requires a box. You can search for
   # boxes at https://atlas.hashicorp.com/search.
-  config.vm.box = "opensuse/openSUSE-42.2-x86_64"
+  config.vm.box = 'opensuse/openSUSE-42.2-x86_64'
 
   # Disable automatic box update checking. If you disable this, then
   # boxes will only be checked for updates when the user runs
@@ -22,7 +24,7 @@ Vagrant.configure(2) do |config|
   # Create a forwarded port mapping which allows access to a specific port
   # within the machine from a port on the host machine. In the example below,
   # accessing "localhost:8080" will access port 80 on the guest machine.
-  config.vm.network "forwarded_port", guest: 3000, host: 3000
+  config.vm.network 'forwarded_port', guest: 3000, host: 3000
 
   # Create a private network, which allows host-only access to the machine
   # using a specific IP.
@@ -47,8 +49,8 @@ Vagrant.configure(2) do |config|
   # mount without working about the group mismatch
   VAGRANT_UID = 1000 # User vagrant
   VAGRANT_GID = 100  # Group users
-  config.vm.synced_folder ".", "/vagrant",
-    owner: VAGRANT_UID, group: VAGRANT_GID
+  config.vm.synced_folder '.', '/vagrant',
+                          owner: VAGRANT_UID, group: VAGRANT_GID
 
   # Provider-specific configuration so you can fine-tune various
   # backing providers for Vagrant. These expose provider-specific options.
@@ -75,7 +77,7 @@ Vagrant.configure(2) do |config|
   # Enable provisioning with a shell script. Additional provisioners such as
   # Puppet, Chef, Ansible, Salt, and Docker are also available. Please see the
   # documentation for more information about their specific syntax and use.
-  config.vm.provision :shell, path: "bootstrap.sh"
+  config.vm.provision :shell, path: 'bootstrap.sh'
   # config.vm.provision "shell", inline: <<-SHELL
   #   sudo apt-get update
   #   sudo apt-get install -y apache2
diff --git a/app/controllers/admin/base_controller.rb b/app/controllers/admin/base_controller.rb
index 8c2db1f4..e2c31014 100644
--- a/app/controllers/admin/base_controller.rb
+++ b/app/controllers/admin/base_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class BaseController < ApplicationController
     before_action :verify_user_admin
@@ -9,7 +11,7 @@ module Admin
     end
 
     def verify_user_admin
-      if (current_user.nil?)
+      if current_user.nil?
         redirect_to sign_in_path
         return false
       end
@@ -17,7 +19,7 @@ module Admin
              (current_user.has_cached_role? :info_desk, :any) || (current_user.has_cached_role? :organization_admin, :any) ||
              (current_user.has_cached_role? :volunteers_coordinator, :any) ||
              (current_user.has_cached_role? :track_organizer, :any) || current_user.is_admin
-        raise CanCan::AccessDenied.new('You are not authorized to access this page.')
+        raise CanCan::AccessDenied, 'You are not authorized to access this page.'
       end
     end
   end
diff --git a/app/controllers/admin/booths_controller.rb b/app/controllers/admin/booths_controller.rb
index e41d11d3..ebe5869e 100644
--- a/app/controllers/admin/booths_controller.rb
+++ b/app/controllers/admin/booths_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class BoothsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -51,7 +53,7 @@ module Admin
     def update
       @url = admin_conference_booth_path(@conference.short_title, @booth.id)
 
-      @booth.update_attributes(booth_params)
+      @booth.update(booth_params)
 
       if @booth.save
         redirect_to admin_conference_booths_path,
@@ -67,9 +69,7 @@ module Admin
       @booth.accept!
 
       if @booth.save
-        if @conference.email_settings.send_on_booths_acceptance
-          Mailbot.conference_booths_acceptance_mail(@booth).deliver
-        end
+        Mailbot.conference_booths_acceptance_mail(@booth).deliver if @conference.email_settings.send_on_booths_acceptance
         redirect_to admin_conference_booths_path(conference_id: @conference.short_title),
                     notice: 'Booth successfully accepted!'
       else
diff --git a/app/controllers/admin/campaigns_controller.rb b/app/controllers/admin/campaigns_controller.rb
index 142e07ac..271b253f 100644
--- a/app/controllers/admin/campaigns_controller.rb
+++ b/app/controllers/admin/campaigns_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class CampaignsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -25,7 +27,7 @@ module Admin
     def edit; end
 
     def update
-      if @campaign.update_attributes(campaign_params)
+      if @campaign.update(campaign_params)
         redirect_to admin_conference_campaigns_path(conference_id: @conference.short_title),
                     notice: "Campaign '#{@campaign.name}' successfully updated."
       else
diff --git a/app/controllers/admin/cfps_controller.rb b/app/controllers/admin/cfps_controller.rb
index 18b493eb..5102951a 100644
--- a/app/controllers/admin/cfps_controller.rb
+++ b/app/controllers/admin/cfps_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class CfpsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -33,7 +35,7 @@ module Admin
 
       send_mail_on_cfp_dates_updates = @cfp.notify_on_cfp_date_update?
 
-      if @cfp.update_attributes(cfp_params)
+      if @cfp.update(cfp_params)
         ConferenceCfpUpdateMailJob.perform_later(@conference) if send_mail_on_cfp_dates_updates
         redirect_to admin_conference_program_cfps_path(@conference.short_title),
                     notice: 'Call for papers successfully updated.'
diff --git a/app/controllers/admin/comments_controller.rb b/app/controllers/admin/comments_controller.rb
index cb57464d..5dfbe232 100644
--- a/app/controllers/admin/comments_controller.rb
+++ b/app/controllers/admin/comments_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class CommentsController < Admin::BaseController
     load_and_authorize_resource
@@ -20,9 +22,9 @@ module Admin
       Comment.accessible_by(current_ability).joins('INNER JOIN events ON commentable_id = events.id').order('events.title', 'comments.created_at DESC')
     end
 
-# Grouping all comments by conference, and by event. It returns {:conference => {:event => [{comment_2}, {comment_1 }]}}
+    # Grouping all comments by conference, and by event. It returns {:conference => {:event => [{comment_2}, {comment_1 }]}}
     def grouped_comments(remarks)
-      remarks.group_by{ |comment| comment.commentable.program.conference }.map {|conference, comments| [conference, comments.group_by{|comment| comment.commentable}]}.to_h
+      remarks.group_by { |comment| comment.commentable.program.conference }.map { |conference, comments| [conference, comments.group_by(&:commentable)] }.to_h
     end
   end
 end
diff --git a/app/controllers/admin/commercials_controller.rb b/app/controllers/admin/commercials_controller.rb
index 1bc587ce..11c3ea58 100644
--- a/app/controllers/admin/commercials_controller.rb
+++ b/app/controllers/admin/commercials_controller.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Admin
   class CommercialsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
-    load_and_authorize_resource through: :conference, except: [:new, :create]
+    load_and_authorize_resource through: :conference, except: %i[new create]
 
     def index
       @commercials = @conference.commercials
@@ -43,7 +45,7 @@ module Admin
     def render_commercial
       result = Commercial.render_from_url(params[:url])
       if result[:error]
-        render text: result[:error], status: 400
+        render text: result[:error], status: :bad_request
       else
         render text: result[:html]
       end
diff --git a/app/controllers/admin/conferences_controller.rb b/app/controllers/admin/conferences_controller.rb
index 1fc978af..9005de0c 100644
--- a/app/controllers/admin/conferences_controller.rb
+++ b/app/controllers/admin/conferences_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class ConferencesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -22,11 +24,11 @@ module Admin
 
       @total_withdrawn = Event.where(state: :withdrawn).count
       @new_withdrawn = Event
-          .where('state = ? and created_at > ?', 'withdrawn', current_user.last_sign_in_at).count
+                       .where('state = ? and created_at > ?', 'withdrawn', current_user.last_sign_in_at).count
 
       @active_conferences = Conference.get_active_conferences_for_dashboard # pending or the last two
       @deactive_conferences = Conference
-          .get_conferences_without_active_for_dashboard(@active_conferences) # conferences without active
+                              .get_conferences_without_active_for_dashboard(@active_conferences) # conferences without active
       @conferences = @active_conferences + @deactive_conferences
 
       @recent_users = User.limit(5).order(created_at: :desc)
@@ -99,7 +101,7 @@ module Admin
       @conference.assign_attributes(conference_params)
       send_mail_on_conf_update = @conference.notify_on_dates_changed?
 
-      if @conference.update_attributes(conference_params)
+      if @conference.update(conference_params)
         ConferenceDateUpdateMailJob.perform_later(@conference) if send_mail_on_conf_update
         redirect_to edit_admin_conference_path(id: @conference.short_title),
                     notice: 'Conference was successfully updated.'
@@ -121,7 +123,7 @@ module Admin
 
       @total_submissions = @all_events.count
       @new_submissions = @all_events
-          .where('created_at > ?', current_user.last_sign_in_at).count
+                         .where('created_at > ?', current_user.last_sign_in_at).count
 
       @program_length = @conference.current_program_hours
       @new_program_length = @conference.new_program_hours(current_user.last_sign_in_at)
@@ -136,7 +138,7 @@ module Admin
       @conference_progress = @conference.get_status
 
       # Line charts
-      @registrations = {@conference.short_title => @conference.get_registrations_per_week}
+      @registrations = { @conference.short_title => @conference.get_registrations_per_week }
       @registration_weeks = [0]
       @registration_weeks.push(@registrations[@conference.short_title].length)
 
@@ -173,9 +175,9 @@ module Admin
 
       @difficulty_levels_distribution = @conference.difficulty_levels_distribution
       @difficulty_levels_distribution_confirmed = @conference
-          .difficulty_levels_distribution(:confirmed)
+                                                  .difficulty_levels_distribution(:confirmed)
       @difficulty_levels_distribution_withdrawn = @conference
-          .difficulty_levels_distribution(:withdrawn)
+                                                  .difficulty_levels_distribution(:withdrawn)
 
       @tracks_distribution = @conference.tracks_distribution
       @tracks_distribution_confirmed = @conference.tracks_distribution(:confirmed)
diff --git a/app/controllers/admin/contacts_controller.rb b/app/controllers/admin/contacts_controller.rb
index 1003e098..a0364251 100644
--- a/app/controllers/admin/contacts_controller.rb
+++ b/app/controllers/admin/contacts_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class ContactsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
diff --git a/app/controllers/admin/difficulty_levels_controller.rb b/app/controllers/admin/difficulty_levels_controller.rb
index 7e02412c..0669c8cc 100644
--- a/app/controllers/admin/difficulty_levels_controller.rb
+++ b/app/controllers/admin/difficulty_levels_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class DifficultyLevelsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -5,7 +7,7 @@ module Admin
     load_and_authorize_resource through: :program
 
     def index
-#       authorize! :index, DifficultyLevel.new(program_id: @program.id)
+      #       authorize! :index, DifficultyLevel.new(program_id: @program.id)
     end
 
     def edit; end
@@ -26,7 +28,7 @@ module Admin
     end
 
     def update
-      if @difficulty_level.update_attributes(difficulty_level_params)
+      if @difficulty_level.update(difficulty_level_params)
         redirect_to admin_conference_program_difficulty_levels_path(conference_id: @conference.short_title),
                     notice: 'Difficulty level successfully updated.'
       else
diff --git a/app/controllers/admin/emails_controller.rb b/app/controllers/admin/emails_controller.rb
index a4d6fe04..bb14b35d 100644
--- a/app/controllers/admin/emails_controller.rb
+++ b/app/controllers/admin/emails_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class EmailsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -6,11 +8,13 @@ module Admin
     def update
       if @conference.email_settings.update(email_params)
         redirect_to admin_conference_emails_path(
-                    @conference.short_title),
+          @conference.short_title
+        ),
                     notice: 'Email settings have been successfully updated.'
       else
         redirect_to admin_conference_emails_path(
-                    @conference.short_title),
+          @conference.short_title
+        ),
                     error: "Updating email settings failed. #{@conference.email_settings.errors.to_a.join('. ')}."
       end
     end
diff --git a/app/controllers/admin/event_schedules_controller.rb b/app/controllers/admin/event_schedules_controller.rb
index 04713093..8af18289 100644
--- a/app/controllers/admin/event_schedules_controller.rb
+++ b/app/controllers/admin/event_schedules_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class EventSchedulesController < Admin::BaseController
     load_and_authorize_resource :event_schedule
@@ -6,7 +8,7 @@ module Admin
       if @event_schedule.save
         render json: { event_schedule_id: @event_schedule.id }
       else
-        render json: { errors: "The event couldn't be scheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: 422
+        render json: { errors: "The event couldn't be scheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: :unprocessable_entity
       end
     end
 
@@ -14,7 +16,7 @@ module Admin
       if @event_schedule.update(event_schedule_params)
         render json: { event_schedule_id: @event_schedule.id }
       else
-        render json: { errors: "The event couldn't be scheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: 422
+        render json: { errors: "The event couldn't be scheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: :unprocessable_entity
       end
     end
 
@@ -22,7 +24,7 @@ module Admin
       if @event_schedule.destroy
         render json: {}
       else
-        render json: { errors: "The event couldn't be unscheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: 422
+        render json: { errors: "The event couldn't be unscheduled. #{@event_schedule.errors.full_messages.join('. ')}" }, status: :unprocessable_entity
       end
     end
 
diff --git a/app/controllers/admin/event_types_controller.rb b/app/controllers/admin/event_types_controller.rb
index 4576ad5d..a171b427 100644
--- a/app/controllers/admin/event_types_controller.rb
+++ b/app/controllers/admin/event_types_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class EventTypesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -24,7 +26,7 @@ module Admin
     end
 
     def update
-      if @event_type.update_attributes(event_type_params)
+      if @event_type.update(event_type_params)
         redirect_to admin_conference_program_event_types_path(conference_id: @conference.short_title),
                     notice: 'Event type successfully updated.'
       else
diff --git a/app/controllers/admin/events_controller.rb b/app/controllers/admin/events_controller.rb
index 2e9886bf..a79af61c 100644
--- a/app/controllers/admin/events_controller.rb
+++ b/app/controllers/admin/events_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class EventsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -7,7 +9,7 @@ module Admin
     # For some reason this doesn't work, so a workaround is used
     # load_and_authorize_resource :track, through: :program, only: [:index, :show, :edit]
 
-    before_action :assign_tracks, only: [:index, :show, :edit]
+    before_action :assign_tracks, only: %i[index show edit]
 
     def index
       @difficulty_levels = @program.difficulty_levels
@@ -17,7 +19,7 @@ module Admin
       @scheduled_event_distribution = @conference.scheduled_event_distribution
       @file_name = "events_for_#{@conference.short_title}"
       @event_export_option = params[:event_export_option]
-      @export_formats = [:pdf, :csv, :xlsx]
+      @export_formats = %i[pdf csv xlsx]
 
       respond_to do |format|
         format.html
@@ -69,7 +71,7 @@ module Admin
 
     def update
       @languages = @program.languages_list
-      if @event.update_attributes(event_params)
+      if @event.update(event_params)
 
         if request.xhr?
           render js: 'index'
@@ -139,8 +141,8 @@ module Admin
     def vote
       @votes = @event.votes.includes(:user)
 
-      if (votes = current_user.votes.find_by_event_id(params[:id]))
-        votes.update_attributes(rating: params[:rating])
+      if (votes = current_user.votes.find_by(event_id: params[:id]))
+        votes.update(rating: params[:rating])
       else
         @myvote = @event.votes.build
         @myvote.user = current_user
@@ -172,13 +174,14 @@ module Admin
 
     def event_params
       params.require(:event).permit(
-                                    # Set also in proposals controller
-                                    :title, :subtitle, :event_type_id, :abstract, :description, :require_registration, :difficulty_level_id,
-                                    # Set only in admin/events controller
-                                    :track_id, :state, :language, :is_highlight, :max_attendees,
-                                    # Not used anymore?
-                                    :proposal_additional_speakers, :user, :users_attributes,
-                                    speaker_ids: [])
+        # Set also in proposals controller
+        :title, :subtitle, :event_type_id, :abstract, :description, :require_registration, :difficulty_level_id,
+        # Set only in admin/events controller
+        :track_id, :state, :language, :is_highlight, :max_attendees,
+        # Not used anymore?
+        :proposal_additional_speakers, :user, :users_attributes,
+        speaker_ids: []
+      )
     end
 
     def comment_params
diff --git a/app/controllers/admin/lodgings_controller.rb b/app/controllers/admin/lodgings_controller.rb
index 85c5ff26..69fa2df5 100644
--- a/app/controllers/admin/lodgings_controller.rb
+++ b/app/controllers/admin/lodgings_controller.rb
@@ -1,10 +1,11 @@
+# frozen_string_literal: true
+
 module Admin
   class LodgingsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
     load_and_authorize_resource :lodging, through: :conference
 
-    def index
-    end
+    def index; end
 
     def new
       @lodging = @conference.lodgings.new
@@ -24,7 +25,7 @@ module Admin
     def edit; end
 
     def update
-      if @lodging.update_attributes(lodging_params)
+      if @lodging.update(lodging_params)
         redirect_to admin_conference_lodgings_path(conference_id: @conference.short_title),
                     notice: 'Lodging successfully updated.'
       else
diff --git a/app/controllers/admin/organizations_controller.rb b/app/controllers/admin/organizations_controller.rb
index 8562d61a..c3e6910b 100644
--- a/app/controllers/admin/organizations_controller.rb
+++ b/app/controllers/admin/organizations_controller.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Admin
   class OrganizationsController < Admin::BaseController
     load_and_authorize_resource :organization
-    before_action :verify_user, only: [:assign_org_admins, :unassign_org_admins]
+    before_action :verify_user, only: %i[assign_org_admins unassign_org_admins]
 
     def index
       @organizations = Organization.all
@@ -25,7 +27,7 @@ module Admin
     def edit; end
 
     def update
-      if @organization.update_attributes(organization_params)
+      if @organization.update(organization_params)
         redirect_to admin_organizations_path,
                     notice: 'Organization successfully updated'
       else
diff --git a/app/controllers/admin/physical_tickets_controller.rb b/app/controllers/admin/physical_tickets_controller.rb
index 0fb26ad8..6c0414c6 100644
--- a/app/controllers/admin/physical_tickets_controller.rb
+++ b/app/controllers/admin/physical_tickets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class PhysicalTicketsController < Admin::BaseController
     before_action :authenticate_user!
diff --git a/app/controllers/admin/programs_controller.rb b/app/controllers/admin/programs_controller.rb
index 3d9f66d8..1162f2f6 100644
--- a/app/controllers/admin/programs_controller.rb
+++ b/app/controllers/admin/programs_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class ProgramsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -14,7 +16,7 @@ module Admin
       send_mail_on_schedule_public = @program.notify_on_schedule_public?
       event_schedules_count_was = @program.event_schedules.count
 
-      if @program.update_attributes(program_params)
+      if @program.update(program_params)
         ConferenceScheduleUpdateMailJob.perform_later(@conference) if send_mail_on_schedule_public
         respond_to do |format|
           format.html do
@@ -30,7 +32,7 @@ module Admin
             flash.now[:error] = "Updating program failed. #{@program.errors.to_a.join('. ')}."
             render :new
           end
-          format.js { render json: { errors: "The selected schedule couldn't be updated #{@program.errors.to_a.join('. ')}" }, status: 422 }
+          format.js { render json: { errors: "The selected schedule couldn't be updated #{@program.errors.to_a.join('. ')}" }, status: :unprocessable_entity }
         end
       end
     end
diff --git a/app/controllers/admin/questions_controller.rb b/app/controllers/admin/questions_controller.rb
index 71abc7a1..25e3d90a 100644
--- a/app/controllers/admin/questions_controller.rb
+++ b/app/controllers/admin/questions_controller.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Admin
   class QuestionsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
-    load_and_authorize_resource through: :conference, except: [:new, :create]
+    load_and_authorize_resource through: :conference, except: %i[new create]
 
     def index
       authorize! :index, Question.new(conference_id: @conference.id)
@@ -24,9 +26,7 @@ module Admin
       @question.conference_id = @conference.id
       authorize! :create, @question
 
-      if @question.question_type_id == QuestionType.find_by(title: 'Yes/No').id
-        @question.answers = [Answer.find_by(title: 'Yes'), Answer.find_by(title: 'No')]
-      end
+      @question.answers = [Answer.find_by(title: 'Yes'), Answer.find_by(title: 'No')] if @question.question_type_id == QuestionType.find_by(title: 'Yes/No').id
 
       respond_to do |format|
         if @conference.save
@@ -39,14 +39,12 @@ module Admin
 
     # GET questions/1/edit
     def edit
-      if @question.global
-        redirect_to admin_conference_questions_path(conference_id: @conference.short_title), error: 'Sorry, you cannot edit global questions. Create a new one.'
-      end
+      redirect_to admin_conference_questions_path(conference_id: @conference.short_title), error: 'Sorry, you cannot edit global questions. Create a new one.' if @question.global
     end
 
     # PUT questions/1
     def update
-      if @question.update_attributes(question_params)
+      if @question.update(question_params)
         redirect_to admin_conference_questions_path(conference_id: @conference.short_title), notice: "Question '#{@question.title}' for #{@conference.short_title} successfully updated."
       else
         redirect_to admin_conference_questions_path(conference_id: @conference.short_title), notice: "Update of questions for #{@conference.short_title} failed. #{@question.errors.full_messages.join('. ')}"
@@ -56,7 +54,7 @@ module Admin
     # Update questions used for the conference
     def update_conference
       authorize! :update, Question.new(conference_id: @conference.id)
-      if @conference.update_attributes(conference_params)
+      if @conference.update(conference_params)
         redirect_to admin_conference_questions_path(conference_id: @conference.short_title), notice: "Questions for #{@conference.short_title} successfully updated."
       else
         redirect_to admin_conference_questions_path(conference_id: @conference.short_title), notice: "Update of questions for #{@conference.short_title} failed."
@@ -73,12 +71,9 @@ module Admin
           # Delete question and its answers
           begin
             Question.transaction do
-
               @question.destroy
-              @question.answers.each do |a|
-                a.destroy
-              end
-              flash[:notice] = "Deleted question: #{@question.title} and its answers: #{@question.answers.map {|a| a.title}.join ','}"
+              @question.answers.each(&:destroy)
+              flash[:notice] = "Deleted question: #{@question.title} and its answers: #{@question.answers.map(&:title).join ','}"
             end
           rescue ActiveRecord::RecordInvalid
             flash[:error] = 'Could not delete question.'
@@ -95,7 +90,7 @@ module Admin
     private
 
     def question_params
-      params.require(:question).permit(:title, :global, :answer_ids, :question_type_id, :conference_id, answers_attributes: [:id, :title])
+      params.require(:question).permit(:title, :global, :answer_ids, :question_type_id, :conference_id, answers_attributes: %i[id title])
     end
 
     def conference_params
diff --git a/app/controllers/admin/registration_periods_controller.rb b/app/controllers/admin/registration_periods_controller.rb
index 4e48c013..bb56d643 100644
--- a/app/controllers/admin/registration_periods_controller.rb
+++ b/app/controllers/admin/registration_periods_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class RegistrationPeriodsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -21,11 +23,9 @@ module Admin
       end
     end
 
-    def edit
-    end
+    def edit; end
 
-    def show
-    end
+    def show; end
 
     def update
       @registration_period.assign_attributes(registration_period_params)
diff --git a/app/controllers/admin/registrations_controller.rb b/app/controllers/admin/registrations_controller.rb
index 475c18c8..cfe4ece2 100644
--- a/app/controllers/admin/registrations_controller.rb
+++ b/app/controllers/admin/registrations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class RegistrationsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -17,9 +19,9 @@ module Admin
     def edit; end
 
     def update
-      @user.update_attributes(user_params)
+      @user.update(user_params)
 
-      @registration.update_attributes(registration_params)
+      @registration.update(registration_params)
       if @registration.save
         redirect_to admin_conference_registrations_path(@conference.short_title),
                     notice: "Successfully updated registration for #{@registration.user.email}!"
diff --git a/app/controllers/admin/reports_controller.rb b/app/controllers/admin/reports_controller.rb
index b01a4bdc..879e214d 100644
--- a/app/controllers/admin/reports_controller.rb
+++ b/app/controllers/admin/reports_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class ReportsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -13,9 +15,9 @@ module Admin
 
       attended_registrants_ids = @conference.registrations.where(attended: true).pluck(:user_id)
       @missing_event_speakers = EventUser.joins(:event)
-                                .where('event_role = ? and program_id = ?', 'submitter', @program.id)
-                                .where.not(user_id: attended_registrants_ids)
-                                .includes(:user, :event)
+                                         .where('event_role = ? and program_id = ?', 'submitter', @program.id)
+                                         .where.not(user_id: attended_registrants_ids)
+                                         .includes(:user, :event)
     end
   end
 end
diff --git a/app/controllers/admin/resources_controller.rb b/app/controllers/admin/resources_controller.rb
index 89b068c3..2e290fb6 100644
--- a/app/controllers/admin/resources_controller.rb
+++ b/app/controllers/admin/resources_controller.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Admin
   class ResourcesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
-    load_and_authorize_resource :resource, only: [:show, :edit, :update, :destroy]
+    load_and_authorize_resource :resource, only: %i[show edit update destroy]
 
     def index; end
 
@@ -23,7 +25,7 @@ module Admin
     end
 
     def update
-      if @resource.update_attributes(resource_params)
+      if @resource.update(resource_params)
         redirect_to admin_conference_resources_path(conference_id: @conference.short_title),
                     notice: 'Resource successfully updated.'
       else
diff --git a/app/controllers/admin/roles_controller.rb b/app/controllers/admin/roles_controller.rb
index ab7be841..ca455dce 100644
--- a/app/controllers/admin/roles_controller.rb
+++ b/app/controllers/admin/roles_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class RolesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -34,7 +36,7 @@ module Admin
     def update
       role_name = @role.name
 
-      if @role.update_attributes(role_params)
+      if @role.update(role_params)
         url = if @track
                 admin_conference_program_track_role_path(@conference.short_title, @track, @role.name)
               else
diff --git a/app/controllers/admin/rooms_controller.rb b/app/controllers/admin/rooms_controller.rb
index da7dfc57..af83d5cb 100644
--- a/app/controllers/admin/rooms_controller.rb
+++ b/app/controllers/admin/rooms_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class RoomsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -24,7 +26,7 @@ module Admin
     end
 
     def update
-      if @room.update_attributes(room_params)
+      if @room.update(room_params)
         redirect_to admin_conference_venue_rooms_path(conference_id: @conference.short_title),
                     notice: 'Room successfully updated.'
       else
diff --git a/app/controllers/admin/schedules_controller.rb b/app/controllers/admin/schedules_controller.rb
index 9f6c222b..77dd4eb6 100644
--- a/app/controllers/admin/schedules_controller.rb
+++ b/app/controllers/admin/schedules_controller.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 module Admin
   class SchedulesController < Admin::BaseController
     # By authorizing 'conference' resource, we can ensure there will be no unauthorized access to
     # the schedule of a conference, which should not be accessed in the first place
     load_and_authorize_resource :conference, find_by: :short_title
     load_and_authorize_resource :program, through: :conference, singleton: true
-    load_and_authorize_resource :schedule, through: :program, except: [:new, :create]
+    load_and_authorize_resource :schedule, through: :program, except: %i[new create]
     load_resource :event_schedules, through: :schedule
     load_resource :selected_schedule, through: :program, singleton: true
     load_resource :venue, through: :conference, singleton: true
diff --git a/app/controllers/admin/splashpages_controller.rb b/app/controllers/admin/splashpages_controller.rb
index 5f04a67b..6b40d0d1 100644
--- a/app/controllers/admin/splashpages_controller.rb
+++ b/app/controllers/admin/splashpages_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class SplashpagesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -23,7 +25,7 @@ module Admin
     end
 
     def update
-      if @splashpage.update_attributes(splashpage_params)
+      if @splashpage.update(splashpage_params)
         redirect_to admin_conference_splashpage_path,
                     notice: 'Splashpage successfully updated.'
       else
diff --git a/app/controllers/admin/sponsors_controller.rb b/app/controllers/admin/sponsors_controller.rb
index 909c2d7c..d0dc9406 100644
--- a/app/controllers/admin/sponsors_controller.rb
+++ b/app/controllers/admin/sponsors_controller.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 module Admin
   class SponsorsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
     load_and_authorize_resource :sponsor, through: :conference
-    before_action :sponsorship_level_required, only: [:index, :new]
+    before_action :sponsorship_level_required, only: %i[index new]
 
     def index
       authorize! :index, Sponsor.new(conference_id: @conference.id)
@@ -26,9 +28,10 @@ module Admin
     end
 
     def update
-      if @sponsor.update_attributes(sponsor_params)
+      if @sponsor.update(sponsor_params)
         redirect_to admin_conference_sponsors_path(
-                    conference_id: @conference.short_title),
+          conference_id: @conference.short_title
+        ),
                     notice: 'Sponsor successfully updated.'
       else
         flash.now[:error] = "Update sponsor failed: #{@sponsor.errors.full_messages.join('. ')}."
diff --git a/app/controllers/admin/sponsorship_levels_controller.rb b/app/controllers/admin/sponsorship_levels_controller.rb
index 714b1ed5..35882e1d 100644
--- a/app/controllers/admin/sponsorship_levels_controller.rb
+++ b/app/controllers/admin/sponsorship_levels_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class SponsorshipLevelsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -25,9 +27,10 @@ module Admin
     end
 
     def update
-      if @sponsorship_level.update_attributes(sponsorship_level_params)
+      if @sponsorship_level.update(sponsorship_level_params)
         redirect_to admin_conference_sponsorship_levels_path(
-                    conference_id: @conference.short_title),
+          conference_id: @conference.short_title
+        ),
                     notice: 'Sponsorship level successfully updated.'
       else
         flash.now[:error] = "Update Sponsorship level failed: #{@sponsorship_level.errors.full_messages.join('. ')}."
diff --git a/app/controllers/admin/targets_controller.rb b/app/controllers/admin/targets_controller.rb
index a04925b7..a7696ad7 100644
--- a/app/controllers/admin/targets_controller.rb
+++ b/app/controllers/admin/targets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class TargetsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -23,7 +25,7 @@ module Admin
     def edit; end
 
     def update
-      if @target.update_attributes(target_params)
+      if @target.update(target_params)
         redirect_to admin_conference_targets_path(conference_id: @conference.short_title),
                     notice: 'Target successfully updated.'
       else
diff --git a/app/controllers/admin/ticket_scannings_controller.rb b/app/controllers/admin/ticket_scannings_controller.rb
index 488f28a1..f6637111 100644
--- a/app/controllers/admin/ticket_scannings_controller.rb
+++ b/app/controllers/admin/ticket_scannings_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class TicketScanningsController < Admin::BaseController
     before_action :authenticate_user!
diff --git a/app/controllers/admin/tickets_controller.rb b/app/controllers/admin/tickets_controller.rb
index cf6e0f80..b19032a9 100644
--- a/app/controllers/admin/tickets_controller.rb
+++ b/app/controllers/admin/tickets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class TicketsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -27,7 +29,7 @@ module Admin
     def edit; end
 
     def update
-      if @ticket.update_attributes(ticket_params)
+      if @ticket.update(ticket_params)
         redirect_to admin_conference_tickets_path(conference_id: @conference.short_title),
                     notice: 'Ticket successfully updated.'
       else
diff --git a/app/controllers/admin/tracks_controller.rb b/app/controllers/admin/tracks_controller.rb
index 4692f9a1..6e8e02db 100644
--- a/app/controllers/admin/tracks_controller.rb
+++ b/app/controllers/admin/tracks_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class TracksController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -54,7 +56,7 @@ module Admin
     def edit; end
 
     def update
-      if @track.update_attributes(track_params)
+      if @track.update(track_params)
         redirect_to admin_conference_program_tracks_path(conference_id: @conference.short_title),
                     notice: 'Track successfully updated.'
       else
@@ -120,13 +122,13 @@ module Admin
     end
 
     def update_selected_schedule
-      if @track.update_attributes(params.require(:track).permit(:selected_schedule_id))
+      if @track.update(params.require(:track).permit(:selected_schedule_id))
         respond_to do |format|
           format.js { render json: {} }
         end
       else
         respond_to do |format|
-          format.js { render json: { errors: "The selected schedule couldn't be updated #{@track.errors.to_a.join('. ')}" }, status: 422 }
+          format.js { render json: { errors: "The selected schedule couldn't be updated #{@track.errors.to_a.join('. ')}" }, status: :unprocessable_entity }
         end
       end
     end
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index b67792e1..4b3e7cd9 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class UsersController < Admin::BaseController
     load_and_authorize_resource
@@ -36,9 +38,9 @@ module Admin
       # Variable @show_attributes holds the attributes that are visible for the 'show' action
       # If you want to change the attributes that are shown in the 'show' action of users
       # add/remove the attributes in the following string array
-      @show_attributes = %w(name email username nickname affiliation biography registered attended roles created_at
+      @show_attributes = %w[name email username nickname affiliation biography registered attended roles created_at
                             updated_at sign_in_count current_sign_in_at last_sign_in_at
-                            current_sign_in_ip last_sign_in_ip)
+                            current_sign_in_ip last_sign_in_ip]
     end
 
     def update
@@ -49,7 +51,7 @@ module Admin
         end
       end
 
-      if @user.update_attributes(user_params)
+      if @user.update(user_params)
         redirect_to admin_users_path, notice: "Updated #{@user.name} (#{@user.email})!" + message
       else
         redirect_to admin_users_path, error: "Could not update #{@user.name} (#{@user.email}). #{@user.errors.full_messages.join('. ')}."
diff --git a/app/controllers/admin/venue_commercials_controller.rb b/app/controllers/admin/venue_commercials_controller.rb
index 20117e15..e07c04d3 100644
--- a/app/controllers/admin/venue_commercials_controller.rb
+++ b/app/controllers/admin/venue_commercials_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class VenueCommercialsController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -38,7 +40,7 @@ module Admin
     def render_commercial
       result = Commercial.render_from_url(params[:url])
       if result[:error]
-        render text: result[:error], status: 400
+        render text: result[:error], status: :bad_request
       else
         render text: result[:html]
       end
diff --git a/app/controllers/admin/venues_controller.rb b/app/controllers/admin/venues_controller.rb
index ba8531ab..17ba4c99 100644
--- a/app/controllers/admin/venues_controller.rb
+++ b/app/controllers/admin/venues_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class VenuesController < Admin::BaseController
     load_and_authorize_resource :conference, find_by: :short_title
@@ -23,7 +25,7 @@ module Admin
     end
 
     def update
-      if @venue.update_attributes(venue_params)
+      if @venue.update(venue_params)
         redirect_to admin_conference_venue_path(conference_id: @conference.short_title),
                     notice: 'Venue was successfully updated.'
       else
diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 5f18da1c..d9937668 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -1,14 +1,14 @@
+# frozen_string_literal: true
+
 module Admin
   class VersionsController < Admin::BaseController
     load_resource :conference, find_by: :short_title, only: :index
     load_and_authorize_resource class: PaperTrail::Version
 
     def index
-      @conferences_with_role = current_user.is_admin? ? Conference.pluck(:short_title) : Conference.with_role([:organizer, :cfp, :info_desk], current_user).pluck(:short_title)
+      @conferences_with_role = current_user.is_admin? ? Conference.pluck(:short_title) : Conference.with_role(%i[organizer cfp info_desk], current_user).pluck(:short_title)
 
-      if current_user.has_cached_role? :organization_admin, :any
-        @conferences_with_role = Organization.with_role('organization_admin', current_user).map { |org| org.conferences.pluck :short_title }.flatten
-      end
+      @conferences_with_role = Organization.with_role('organization_admin', current_user).map { |org| org.conferences.pluck :short_title }.flatten if current_user.has_cached_role? :organization_admin, :any
       @conferences_with_role.uniq!
 
       return if @conference.blank?
@@ -16,7 +16,7 @@ module Admin
     end
 
     def revert_attribute
-      if params[:attribute] && @version.changeset.reject{ |_, values| values[0].blank? && values[1].blank? }.keys.include?(params[:attribute])
+      if params[:attribute] && @version.changeset.reject { |_, values| values[0].blank? && values[1].blank? }.keys.include?(params[:attribute])
         if @version.item[params[:attribute]] == @version.changeset[params[:attribute]][0]
           flash[:error] = 'The item is already in the state that you are trying to revert it back to'
 
diff --git a/app/controllers/admin/volunteers_controller.rb b/app/controllers/admin/volunteers_controller.rb
index aefa682a..b0b85ffc 100644
--- a/app/controllers/admin/volunteers_controller.rb
+++ b/app/controllers/admin/volunteers_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   class VolunteersController < Admin::BaseController
     include VolunteersHelper
@@ -24,7 +26,7 @@ module Admin
     end
 
     def update
-      if @conference.update_attributes(conference_params)
+      if @conference.update(conference_params)
         redirect_to admin_conference_volunteers_info_path(conference_id: params[:conference_id]), notice: 'Volunteering options were successfully updated.'
       else
         redirect_to admin_conference_volunteers_info_path(conference_id: params[:conference_id]), error: "Volunteering options update failed: #{@conference.errors.full_messages.join '. '}"
diff --git a/app/controllers/api/base_controller.rb b/app/controllers/api/base_controller.rb
index aaa6f130..619901b2 100644
--- a/app/controllers/api/base_controller.rb
+++ b/app/controllers/api/base_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   class BaseController < ActionController::Base
     protect_from_forgery with: :exception
diff --git a/app/controllers/api/v1/conferences_controller.rb b/app/controllers/api/v1/conferences_controller.rb
index 60578587..45976e97 100644
--- a/app/controllers/api/v1/conferences_controller.rb
+++ b/app/controllers/api/v1/conferences_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   module V1
     class ConferencesController < Api::BaseController
diff --git a/app/controllers/api/v1/events_controller.rb b/app/controllers/api/v1/events_controller.rb
index 1cb01ad9..0577eb41 100644
--- a/app/controllers/api/v1/events_controller.rb
+++ b/app/controllers/api/v1/events_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   module V1
     class EventsController < Api::BaseController
@@ -10,9 +12,7 @@ module Api
       def index
         events = Event.includes(:track, :event_type, event_users: :user)
 
-        if @conference
-          events = events.where(program: @conference.program)
-        end
+        events = events.where(program: @conference.program) if @conference
 
         respond_with events.confirmed, callback: params[:callback]
       end
diff --git a/app/controllers/api/v1/rooms_controller.rb b/app/controllers/api/v1/rooms_controller.rb
index ecc959fa..56eb7f28 100644
--- a/app/controllers/api/v1/rooms_controller.rb
+++ b/app/controllers/api/v1/rooms_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   module V1
     class RoomsController < Api::BaseController
diff --git a/app/controllers/api/v1/speakers_controller.rb b/app/controllers/api/v1/speakers_controller.rb
index 2706d2e9..dbb0f697 100644
--- a/app/controllers/api/v1/speakers_controller.rb
+++ b/app/controllers/api/v1/speakers_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   module V1
     class SpeakersController < Api::BaseController
@@ -9,13 +11,13 @@ module Api
 
       def index
         if @conference
-          users = User.joins(event_users: { event: { program: :conference} })
+          users = User.joins(event_users: { event: { program: :conference } })
           users = users.where(conferences: { short_title: @conference.short_title })
         else
           users = User.joins(:event_users)
         end
 
-        users = users.where(event_users: {event_role: :speaker}).uniq
+        users = users.where(event_users: { event_role: :speaker }).uniq
         render json: users, each_serializer: SpeakerSerializer, callback: params['callback']
       end
     end
diff --git a/app/controllers/api/v1/tracks_controller.rb b/app/controllers/api/v1/tracks_controller.rb
index 48a9450f..49d8094b 100644
--- a/app/controllers/api/v1/tracks_controller.rb
+++ b/app/controllers/api/v1/tracks_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Api
   module V1
     class TracksController < Api::BaseController
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 7421a0f0..8f8a5591 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
   before_action :set_paper_trail_whodunnit
   include ApplicationHelper
@@ -11,24 +13,24 @@ class ApplicationController < ActionController::Base
   def store_location
     # store last url - this is needed for post-login redirect to whatever the user last visited.
     return unless request.get?
-    if (request.path != '/accounts/sign_in' &&
-        request.path != '/accounts/sign_up' &&
-        request.path != '/accounts/password/new' &&
-        request.path != '/accounts/password/edit' &&
-        request.path != '/accounts/confirmation' &&
-        request.path != '/accounts/sign_out' &&
-        request.path != '/users/ichain_registration/ichain_sign_up' &&
-        !request.path.starts_with?(Devise.ichain_base_url) &&
-        !request.xhr?) # don't store ajax calls
+    if request.path != '/accounts/sign_in' &&
+       request.path != '/accounts/sign_up' &&
+       request.path != '/accounts/password/new' &&
+       request.path != '/accounts/password/edit' &&
+       request.path != '/accounts/confirmation' &&
+       request.path != '/accounts/sign_out' &&
+       request.path != '/users/ichain_registration/ichain_sign_up' &&
+       !request.path.starts_with?(Devise.ichain_base_url) &&
+       !request.xhr? # don't store ajax calls
       session[:return_to] = request.fullpath
     end
   end
 
   def after_sign_in_path_for(_resource)
     if (can? :view, Conference) &&
-      (!session[:return_to] ||
-      session[:return_to] &&
-      session[:return_to] == root_path)
+       (!session[:return_to] ||
+       session[:return_to] &&
+       session[:return_to] == root_path)
       admin_conferences_path
     else
       session[:return_to] || root_path
@@ -61,10 +63,10 @@ class ApplicationController < ActionController::Base
     Rails.logger.debug('User is disabled!')
     sign_out(current_user)
     mail = User.admin.first ? User.admin.first.email : 'the admin!'
-    redirect_to User.ichain_logout_url, error:  "This User is disabled. Please contact #{mail}!"
+    redirect_to User.ichain_logout_url, error: "This User is disabled. Please contact #{mail}!"
   end
 
   def not_found
-    raise ActionController::RoutingError.new('Not Found')
+    raise ActionController::RoutingError, 'Not Found'
   end
 end
diff --git a/app/controllers/booths_controller.rb b/app/controllers/booths_controller.rb
index f0457b88..a3f3c403 100644
--- a/app/controllers/booths_controller.rb
+++ b/app/controllers/booths_controller.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 class BoothsController < ApplicationController
   before_action :authenticate_user!
   load_resource :conference, find_by: :short_title
   load_and_authorize_resource through: :conference
-  skip_authorize_resource only: [:withdraw, :confirm, :restart]
+  skip_authorize_resource only: %i[withdraw confirm restart]
 
   def index
     @booths = current_user.booths.where(conference_id: @conference.id).uniq
@@ -34,7 +36,7 @@ class BoothsController < ApplicationController
 
   def update
     @url = conference_booth_path(@conference.short_title, @booth.id)
-    @booth.update_attributes(booth_params)
+    @booth.update(booth_params)
 
     if @booth.save
       redirect_to conference_booths_path,
diff --git a/app/controllers/commercials_controller.rb b/app/controllers/commercials_controller.rb
index 779b5d39..b83f0b7a 100644
--- a/app/controllers/commercials_controller.rb
+++ b/app/controllers/commercials_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommercialsController < ApplicationController
   load_resource :conference, find_by: :short_title
   before_action :set_event
@@ -35,7 +37,7 @@ class CommercialsController < ApplicationController
   def render_commercial
     result = Commercial.render_from_url(params[:url])
     if result[:error]
-      render text: result[:error], status: 400
+      render text: result[:error], status: :bad_request
     else
       render text: result[:html]
     end
diff --git a/app/controllers/conference_registrations_controller.rb b/app/controllers/conference_registrations_controller.rb
index f2751a31..a3234607 100644
--- a/app/controllers/conference_registrations_controller.rb
+++ b/app/controllers/conference_registrations_controller.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 class ConferenceRegistrationsController < ApplicationController
-  before_action :authenticate_user!, except: [:new, :create]
+  before_action :authenticate_user!, except: %i[new create]
   load_resource :conference, find_by: :short_title
-  authorize_resource :conference_registrations, class: Registration, except: [:new, :create]
-  before_action :set_registration, only: [:edit, :update, :destroy, :show]
+  authorize_resource :conference_registrations, class: Registration, except: %i[new create]
+  before_action :set_registration, only: %i[edit update destroy show]
 
   def new
     @registration = Registration.new(conference_id: @conference.id)
@@ -54,9 +56,7 @@ class ConferenceRegistrationsController < ApplicationController
       ahoy.track 'Registered', title: 'New registration'
 
       # Sign in the new user
-      unless current_user
-        sign_in(@registration.user)
-      end
+      sign_in(@registration.user) unless current_user
 
       if @conference.tickets.any? && !current_user.supports?(@conference)
         redirect_to conference_tickets_path(@conference.short_title),
@@ -73,7 +73,7 @@ class ConferenceRegistrationsController < ApplicationController
   end
 
   def update
-    if @registration.update_attributes(registration_params)
+    if @registration.update(registration_params)
       redirect_to  conference_conference_registration_path(@conference.short_title),
                    notice: 'Registration was successfully updated.'
     else
@@ -110,14 +110,15 @@ class ConferenceRegistrationsController < ApplicationController
 
   def registration_params
     params.require(:registration)
-        .permit(
-          :conference_id, :arrival, :departure,
-          :volunteer,
-          vchoice_ids: [], qanswer_ids: [],
-          qanswers_attributes: [],
-          event_ids: [],
-          user_attributes: [
-            :username, :email, :name, :password, :password_confirmation]
-    )
+          .permit(
+            :conference_id, :arrival, :departure,
+            :volunteer,
+            vchoice_ids: [], qanswer_ids: [],
+            qanswers_attributes: [],
+            event_ids: [],
+            user_attributes: %i[
+              username email name password password_confirmation
+            ]
+          )
   end
 end
diff --git a/app/controllers/conferences_controller.rb b/app/controllers/conferences_controller.rb
index f46d29ae..021cc2d0 100644
--- a/app/controllers/conferences_controller.rb
+++ b/app/controllers/conferences_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferencesController < ApplicationController
   protect_from_forgery with: :null_session
   before_action :respond_to_options
@@ -21,9 +23,7 @@ class ConferencesController < ApplicationController
 
     splashpage = @conference.splashpage
 
-    unless splashpage.present?
-      redirect_to admin_conference_splashpage_path(@conference.short_title) && return
-    end
+    redirect_to admin_conference_splashpage_path(@conference.short_title) && return if splashpage.blank?
 
     if splashpage.include_cfp
       cfps = @conference.program.cfps
@@ -42,16 +42,10 @@ class ConferencesController < ApplicationController
           :room
         ).order('tracks.name')
       end
-      if splashpage.include_booths
-        @booths = @conference.confirmed_booths.order('title')
-      end
-    end
-    if splashpage.include_registrations || splashpage.include_tickets
-      @tickets = @conference.tickets.order('price_cents')
-    end
-    if splashpage.include_lodgings
-      @lodgings = @conference.lodgings.order('name')
+      @booths = @conference.confirmed_booths.order('title') if splashpage.include_booths
     end
+    @tickets = @conference.tickets.order('price_cents') if splashpage.include_registrations || splashpage.include_tickets
+    @lodgings = @conference.lodgings.order('name') if splashpage.include_lodgings
     if splashpage.include_sponsors
       @sponsorship_levels = @conference.sponsorship_levels.eager_load(
         :sponsors
@@ -71,8 +65,10 @@ class ConferencesController < ApplicationController
   end
 
   def respond_to_options
-    respond_to do |format|
-      format.html { head :ok }
-    end if request.options?
+    if request.options?
+      respond_to do |format|
+        format.html { head :ok }
+      end
+    end
   end
 end
diff --git a/app/controllers/confirmations_controller.rb b/app/controllers/confirmations_controller.rb
index 3b8c9837..eaf5bb22 100644
--- a/app/controllers/confirmations_controller.rb
+++ b/app/controllers/confirmations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConfirmationsController < Devise::ConfirmationsController
   protected
 
diff --git a/app/controllers/openids_controller.rb b/app/controllers/openids_controller.rb
index 35bc0bae..3bccba2f 100644
--- a/app/controllers/openids_controller.rb
+++ b/app/controllers/openids_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class OpenidsController < ApplicationController
   load_and_authorize_resource :user
   load_and_authorize_resource through: :user
diff --git a/app/controllers/organizations_controller.rb b/app/controllers/organizations_controller.rb
index 2ebbdeeb..86713e8c 100644
--- a/app/controllers/organizations_controller.rb
+++ b/app/controllers/organizations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class OrganizationsController < ApplicationController
   load_and_authorize_resource :organization
 
diff --git a/app/controllers/payments_controller.rb b/app/controllers/payments_controller.rb
index 322ed397..afa68635 100644
--- a/app/controllers/payments_controller.rb
+++ b/app/controllers/payments_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PaymentsController < ApplicationController
   before_action :authenticate_user!
   load_and_authorize_resource
@@ -10,9 +12,7 @@ class PaymentsController < ApplicationController
 
   def new
     @total_amount_to_pay = Ticket.total_price(@conference, current_user, paid: false)
-    if @total_amount_to_pay.zero?
-      raise CanCan::AccessDenied.new('Nothing to pay for!', :new, Payment)
-    end
+    raise CanCan::AccessDenied.new('Nothing to pay for!', :new, Payment) if @total_amount_to_pay.zero?
     @unpaid_ticket_purchases = current_user.ticket_purchases.unpaid.by_conference(@conference)
   end
 
diff --git a/app/controllers/physical_tickets_controller.rb b/app/controllers/physical_tickets_controller.rb
index c3cc40cb..afa83baf 100644
--- a/app/controllers/physical_tickets_controller.rb
+++ b/app/controllers/physical_tickets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PhysicalTicketsController < ApplicationController
   before_action :authenticate_user!
   load_resource :conference, find_by: :short_title
diff --git a/app/controllers/proposals_controller.rb b/app/controllers/proposals_controller.rb
index 7ea81dc0..eb30d273 100644
--- a/app/controllers/proposals_controller.rb
+++ b/app/controllers/proposals_controller.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 class ProposalsController < ApplicationController
-  before_action :authenticate_user!, except: [:show, :new, :create]
+  before_action :authenticate_user!, except: %i[show new create]
   load_resource :conference, find_by: :short_title
   load_resource :program, through: :conference, singleton: true
   load_and_authorize_resource :event, parent: false, through: :program
   # We authorize manually in these actions
-  skip_authorize_resource :event, only: [:confirm, :restart, :withdraw]
+  skip_authorize_resource :event, only: %i[confirm restart withdraw]
 
   def index
     @event = @program.events.new
@@ -168,8 +170,7 @@ class ProposalsController < ApplicationController
     params.require(:event).permit(:event_type_id, :track_id, :difficulty_level_id,
                                   :title, :subtitle, :abstract, :description,
                                   :require_registration, :max_attendees, :language,
-                                  speaker_ids: []
-                                 )
+                                  speaker_ids: [])
   end
 
   def user_params
diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index e020d217..2b022571 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RegistrationsController < Devise::RegistrationsController
   prepend_before_action :check_captcha, only: [:create]
 
diff --git a/app/controllers/schedules_controller.rb b/app/controllers/schedules_controller.rb
index eb145730..13e10795 100644
--- a/app/controllers/schedules_controller.rb
+++ b/app/controllers/schedules_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SchedulesController < ApplicationController
   load_and_authorize_resource
   protect_from_forgery with: :null_session
@@ -8,11 +10,9 @@ class SchedulesController < ApplicationController
   def show
     @rooms = @conference.venue.rooms if @conference.venue
     schedules = @program.selected_event_schedules
-    unless schedules
-      redirect_to events_conference_schedule_path(@conference.short_title)
-    end
+    redirect_to events_conference_schedule_path(@conference.short_title) unless schedules
 
-    @events_xml = schedules.map(&:event).group_by{ |event| event.time.to_date } if schedules
+    @events_xml = schedules.map(&:event).group_by { |event| event.time.to_date } if schedules
     @dates = @conference.start_date..@conference.end_date
     @step_minutes = @program.schedule_interval.minutes
     @conf_start = @conference.start_hour
@@ -20,7 +20,7 @@ class SchedulesController < ApplicationController
 
     # the schedule takes you to today if it is a date of the schedule
     @current_day = @conference.current_conference_day
-    @day = @current_day.present? ? @current_day : @dates.first
+    @day = @current_day.presence || @dates.first
     unless @current_day
       # the schedule takes you to the current time if it is beetween the start and the end time.
       @hour_column = @conference.hours_from_start_time(@conf_start, @conference.end_hour)
@@ -37,7 +37,7 @@ class SchedulesController < ApplicationController
     @dates = @conference.start_date..@conference.end_date
 
     @events_schedules = @program.selected_event_schedules
-    @events_schedules = [] unless @events_schedules
+    @events_schedules ||= []
 
     @unscheduled_events = @program.events.confirmed - @events_schedules.map(&:event)
 
@@ -48,8 +48,10 @@ class SchedulesController < ApplicationController
   private
 
   def respond_to_options
-    respond_to do |format|
-      format.html { head :ok }
-    end if request.options?
+    if request.options?
+      respond_to do |format|
+        format.html { head :ok }
+      end
+    end
   end
 end
diff --git a/app/controllers/subscriptions_controller.rb b/app/controllers/subscriptions_controller.rb
index d5111835..e0e4daac 100644
--- a/app/controllers/subscriptions_controller.rb
+++ b/app/controllers/subscriptions_controller.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class SubscriptionsController < ApplicationController
   before_action :authenticate_user!
   load_resource :conference, find_by: :short_title
-  load_and_authorize_resource only: [:create, :destroy], through: :conference
+  load_and_authorize_resource only: %i[create destroy], through: :conference
 
   def create
     @subscription = current_user.subscriptions.build(conference_id: @conference.id)
diff --git a/app/controllers/ticket_purchases_controller.rb b/app/controllers/ticket_purchases_controller.rb
index 4221fb4e..dac4e34f 100644
--- a/app/controllers/ticket_purchases_controller.rb
+++ b/app/controllers/ticket_purchases_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TicketPurchasesController < ApplicationController
   before_action :authenticate_user!
   load_resource :conference, find_by: :short_title
diff --git a/app/controllers/tickets_controller.rb b/app/controllers/tickets_controller.rb
index 94893c27..270b83b4 100644
--- a/app/controllers/tickets_controller.rb
+++ b/app/controllers/tickets_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TicketsController < ApplicationController
   before_action :authenticate_user!
   load_resource :conference, find_by: :short_title
@@ -8,8 +10,6 @@ class TicketsController < ApplicationController
   def index; end
 
   def check_load_resource
-    if @tickets.empty?
-      redirect_to root_path, notice: "There are no tickets available for #{@conference.title}!"
-    end
+    redirect_to root_path, notice: "There are no tickets available for #{@conference.title}!" if @tickets.empty?
   end
 end
diff --git a/app/controllers/tracks_controller.rb b/app/controllers/tracks_controller.rb
index 6b584d22..6db26991 100644
--- a/app/controllers/tracks_controller.rb
+++ b/app/controllers/tracks_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TracksController < ApplicationController
   load_resource :conference, find_by: :short_title
   load_resource :program, through: :conference, singleton: true
@@ -29,7 +31,7 @@ class TracksController < ApplicationController
   end
 
   def update
-    if @track.update_attributes(track_params)
+    if @track.update(track_params)
       redirect_to conference_program_tracks_path(conference_id: @conference.short_title),
                   notice: 'Track request successfully updated.'
     else
diff --git a/app/controllers/users/omniauth_callbacks_controller.rb b/app/controllers/users/omniauth_callbacks_controller.rb
index 1d0400cd..b126f2c8 100644
--- a/app/controllers/users/omniauth_callbacks_controller.rb
+++ b/app/controllers/users/omniauth_callbacks_controller.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 module Users
   class OmniauthCallbacksController < Devise::OmniauthCallbacksController
-    skip_before_filter :verify_authenticity_token
+    skip_before_action :verify_authenticity_token
     skip_authorization_check
 
     User.omniauth_providers.each do |provider|
@@ -11,7 +13,7 @@ module Users
 
     def handle(provider)
       auth_hash = request.env['omniauth.auth']
-      unless auth_hash.info.email.present?
+      if auth_hash.info.email.blank?
         flash[:error] = "Email field is missing in your #{provider} account"
         redirect_to new_user_registration_path
         return
@@ -27,15 +29,13 @@ module Users
 
       begin
         user.save!
-        if openid.user != user
-          openid.user = user
-        end
+        openid.user = user if openid.user != user
         openid.save!
 
         sign_in user
         redirect_to request.env['omniauth.origin'] || root_path,
                     notice: "#{user.email} signed in successfully with #{provider}"
-      rescue => e
+      rescue StandardError => e
         flash[:error] = e.message
         redirect_back_or_to new_user_registration_path
       end
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 6c027abd..9337f893 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UsersController < ApplicationController
   load_and_authorize_resource
 
@@ -7,8 +9,7 @@ class UsersController < ApplicationController
   end
 
   # GET /users/1/edit
-  def edit
-  end
+  def edit; end
 
   # PATCH/PUT /users/1
   def update
@@ -22,8 +23,8 @@ class UsersController < ApplicationController
 
   private
 
-    # Only allow a trusted parameter "white list" through.
-    def user_params
-      params.require(:user).permit(:name, :biography, :nickname, :affiliation)
-    end
+  # Only allow a trusted parameter "white list" through.
+  def user_params
+    params.require(:user).permit(:name, :biography, :nickname, :affiliation)
+  end
 end
diff --git a/app/helpers/admin/volunteers_helper.rb b/app/helpers/admin/volunteers_helper.rb
index 6115f15b..0833c771 100644
--- a/app/helpers/admin/volunteers_helper.rb
+++ b/app/helpers/admin/volunteers_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Admin
   module VolunteersHelper
     def can_manage_volunteers?(conference)
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index f0311c7a..8c461d8f 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
   # Returns a string build from the start and end date of the given conference.
   #
@@ -60,7 +62,7 @@ module ApplicationHelper
   end
 
   def difficulty_levels(conference)
-    all = conference.program.difficulty_levels.map {|t| t.title}
+    all = conference.program.difficulty_levels.map(&:title)
     first = all[0...-1]
     last = all[-1]
     ts = ''
@@ -83,16 +85,14 @@ module ApplicationHelper
   # Output will be 'title, description and conference'
   def updated_attributes(version)
     version.changeset
-      .reject{ |_, values| values[0].blank? && values[1].blank? }
-      .keys.map{ |key| key.gsub('_id', '').tr('_', ' ')}.join(', ')
-      .reverse.sub(',', ' dna ').reverse
+           .reject { |_, values| values[0].blank? && values[1].blank? }
+           .keys.map { |key| key.gsub('_id', '').tr('_', ' ') }.join(', ')
+           .reverse.sub(',', ' dna ').reverse
   end
 
   def normalize_array_length(hashmap, length)
     hashmap.each_value do |value|
-      if value.length < length
-        value.fill(value[-1], value.length...length)
-      end
+      value.fill(value[-1], value.length...length) if value.length < length
     end
   end
 
@@ -115,28 +115,26 @@ module ApplicationHelper
     other_event_schedules.each do |other_event_schedule|
       next unless other_event_schedule.event.confirmed?
       other_event_time_range = (other_event_schedule.start_time.strftime '%Y-%m-%d %H:%M')...(other_event_schedule.end_time.strftime '%Y-%m-%d %H:%M')
-      if (event_time_range.to_a & other_event_time_range.to_a).present?
-        concurrent_events << other_event_schedule.event
-      end
+      concurrent_events << other_event_schedule.event if (event_time_range.to_a & other_event_time_range.to_a).present?
     end
     concurrent_events
   end
 
   def speaker_links(event)
-    safe_join(event.speakers.map{ |speaker| link_to speaker.name, admin_user_path(speaker) }, ',')
+    safe_join(event.speakers.map { |speaker| link_to speaker.name, admin_user_path(speaker) }, ',')
   end
 
   def speaker_selector_input(form)
-    users = User.active.pluck(:id, :name, :username, :email).map { |user| [user[0], user[1].blank? ? user[2] : user[1], user[2], user[3]] }.sort_by { |user| user[1].downcase }
+    users = User.active.pluck(:id, :name, :username, :email).map { |user| [user[0], user[1].presence || user[2], user[2], user[3]] }.sort_by { |user| user[1].downcase }
     form.input :speakers, as: :select,
-                          collection: options_for_select(users.map {|user| ["#{user[1]} (#{user[2]}) #{user[3]}", user[0]]}, @event.speakers.map(&:id)),
+                          collection: options_for_select(users.map { |user| ["#{user[1]} (#{user[2]}) #{user[3]}", user[0]] }, @event.speakers.map(&:id)),
                           include_blank: false, label: 'Speakers', input_html: { class: 'select-help-toggle', multiple: 'true' }
   end
 
   def responsibles_selector_input(form)
-    users = User.active.pluck(:id, :name, :username, :email).map { |user| [user[0], user[1].blank? ? user[2] : user[1], user[2], user[3]] }.sort_by { |user| user[1].downcase }
+    users = User.active.pluck(:id, :name, :username, :email).map { |user| [user[0], user[1].presence || user[2], user[2], user[3]] }.sort_by { |user| user[1].downcase }
     form.input :responsibles, as: :select,
-                              collection: options_for_select(users.map {|user| ["#{user[1]} (#{user[2]}) #{user[3]}", user[0]]}, @booth.responsibles.map(&:id)),
+                              collection: options_for_select(users.map { |user| ["#{user[1]} (#{user[2]}) #{user[3]}", user[0]] }, @booth.responsibles.map(&:id)),
                               include_blank: false, label: 'Responsibles', input_html: { class: 'select-help-toggle', multiple: 'true' },
                               hint: 'The people responsible for the booth. You can only select existing users.'
   end
@@ -154,9 +152,7 @@ module ApplicationHelper
   end
 
   def rescheduling_hint(affected_event_count)
-    if affected_event_count > 0
-      "You have #{affected_event_count} scheduled #{'event'.pluralize(affected_event_count)}. Changing the conference hours will unschedule those scheduled outside the conference hours."
-    end
+    "You have #{affected_event_count} scheduled #{'event'.pluralize(affected_event_count)}. Changing the conference hours will unschedule those scheduled outside the conference hours." if affected_event_count > 0
   end
 
   ##
diff --git a/app/helpers/conference_helper.rb b/app/helpers/conference_helper.rb
index 20ef6ba4..d6629814 100644
--- a/app/helpers/conference_helper.rb
+++ b/app/helpers/conference_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ConferenceHelper
   # Return true if only call_for_papers or call_for_tracks or call_for_booths is open
   def one_call_open(*calls)
@@ -6,7 +8,7 @@ module ConferenceHelper
   # Return true if exactly two of those calls are open: call_for_papers , call_for_tracks , call_for_booths
 
   def two_calls_open(*calls)
-    calls.count{ |call| call.try(:open?) } == 2
+    calls.count { |call| call.try(:open?) } == 2
   end
 
   # URL for sponsorship emails
diff --git a/app/helpers/date_time_helper.rb b/app/helpers/date_time_helper.rb
index a8e4f660..7e15e930 100644
--- a/app/helpers/date_time_helper.rb
+++ b/app/helpers/date_time_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DateTimeHelper
   ##
   # Includes functions related to date or time manipulations
diff --git a/app/helpers/events_helper.rb b/app/helpers/events_helper.rb
index 1140898b..5e67e0a9 100644
--- a/app/helpers/events_helper.rb
+++ b/app/helpers/events_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module EventsHelper
   ##
   # Includes functions related to events
diff --git a/app/helpers/format_helper.rb b/app/helpers/format_helper.rb
index a41c584e..63b6a367 100644
--- a/app/helpers/format_helper.rb
+++ b/app/helpers/format_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module FormatHelper
   ##
   # Includes functions related to formatting (like adding classes, colors)
@@ -44,24 +46,23 @@ module FormatHelper
   def target_progress_color(progress)
     progress = progress.to_i
     result =
-    case
-    when progress >= 90 then 'green'
-    when progress < 90 && progress >= 80 then 'orange'
-    else 'red'
-    end
+      if progress >= 90 then 'green'
+      elsif progress < 90 && progress >= 80 then 'orange'
+      else 'red'
+      end
 
     result
   end
 
   def days_left_color(days_left)
     days_left = days_left.to_i
-    if days_left > 30
-      result = 'green'
-    elsif days_left < 30 && days_left > 10
-      result = 'orange'
-    else
-      result = 'red'
-    end
+    result = if days_left > 30
+               'green'
+             elsif days_left < 30 && days_left > 10
+               'orange'
+             else
+               'red'
+             end
     result
   end
 
@@ -116,7 +117,7 @@ module FormatHelper
   end
 
   def word_pluralize(count, singular, plural = nil)
-    word = if (count == 1 || count =~ /^1(\.0+)?$/)
+    word = if count == 1 || count =~ /^1(\.0+)?$/
              singular
            else
              plural || singular.pluralize
@@ -134,7 +135,7 @@ module FormatHelper
     g = hexcolor[3..4].to_i(16)
     b = hexcolor[5..6].to_i(16)
     yiq = ((r * 299) + (g * 587) + (b * 114)) / 1000
-    (yiq >= 128) ? 'black' : 'white'
+    yiq >= 128 ? 'black' : 'white'
   end
 
   def td_height(rooms)
@@ -178,17 +179,15 @@ module FormatHelper
     item_class = 'item'
     item_class += ' first' if number == 0
     item_class += ' last' if number == (carousel_number - 1)
-    if (col && ((col / num_cols) == number)) || (!col && number == 0)
-      item_class += ' active'
-    end
+    item_class += ' active' if (col && ((col / num_cols) == number)) || (!col && number == 0)
     item_class
   end
 
   def selected_scheduled?(schedule)
-    (schedule == @selected_schedule) ? 'Yes' : 'No'
+    schedule == @selected_schedule ? 'Yes' : 'No'
   end
 
-  def markdown(text, escape_html=true)
+  def markdown(text, escape_html = true)
     return '' if text.nil?
 
     options = {
@@ -200,7 +199,7 @@ module FormatHelper
     markdown.render(text).html_safe
   end
 
-  def markdown_hint(text='')
+  def markdown_hint(text = '')
     markdown("#{text} Please look at #{link_to '**Markdown Syntax**', 'https://daringfireball.net/projects/markdown/syntax', target: '_blank'} to format your text", false)
   end
 
diff --git a/app/helpers/paths_helper.rb b/app/helpers/paths_helper.rb
index 46e82900..cfedc2bd 100644
--- a/app/helpers/paths_helper.rb
+++ b/app/helpers/paths_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module PathsHelper
   ##
   # Includes functions related to links or redirects
diff --git a/app/helpers/users_helper.rb b/app/helpers/users_helper.rb
index 763a44c9..611bc6db 100644
--- a/app/helpers/users_helper.rb
+++ b/app/helpers/users_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module UsersHelper
   ##
   # Includes functions related to users
@@ -12,10 +14,8 @@ module UsersHelper
     Devise.omniauth_providers.each do |provider|
       provider_key = "#{provider}_key"
       provider_secret = "#{provider}_secret"
-      unless Rails.application.secrets.send(provider_key).blank? || Rails.application.secrets.send(provider_secret).blank?
-        providers << provider
-      end
-      providers << provider if !ENV["OSEM_#{provider.upcase}_KEY"].blank? && !ENV["OSEM_#{provider.upcase}_SECRET"].blank?
+      providers << provider unless Rails.application.secrets.send(provider_key).blank? || Rails.application.secrets.send(provider_secret).blank?
+      providers << provider if ENV["OSEM_#{provider.upcase}_KEY"].present? && ENV["OSEM_#{provider.upcase}_SECRET"].present?
     end
 
     providers.uniq
@@ -25,6 +25,6 @@ module UsersHelper
   # Outputs the roles of a user, including the conferences for which the user has the roles
   # Eg. organizer(oSC13, oSC14), cfp(oSC12, oSC13)
   def show_roles(roles)
-    roles.map{ |x| x[0].titleize + ' (' + x[1].join(', ') + ')' }.join ', '
+    roles.map { |x| x[0].titleize + ' (' + x[1].join(', ') + ')' }.join ', '
   end
 end
diff --git a/app/helpers/versions_helper.rb b/app/helpers/versions_helper.rb
index 5788fe9d..50fadb49 100644
--- a/app/helpers/versions_helper.rb
+++ b/app/helpers/versions_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module VersionsHelper
   ##
   # Groups functions related to change description
@@ -119,10 +121,9 @@ module VersionsHelper
   end
 
   def event_change_description(version)
-    case
-    when version.event == 'create' then 'submitted new'
+    if version.event == 'create' then 'submitted new'
 
-    when version.changeset['state']
+    elsif version.changeset['state']
       case version.changeset['state'][1]
       when 'unconfirmed' then 'accepted'
       when 'withdrawn' then 'withdrew'
diff --git a/app/jobs/application_job.rb b/app/jobs/application_job.rb
index a009ace5..d92ffddc 100644
--- a/app/jobs/application_job.rb
+++ b/app/jobs/application_job.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ApplicationJob < ActiveJob::Base
 end
diff --git a/app/jobs/conference_cfp_update_mail_job.rb b/app/jobs/conference_cfp_update_mail_job.rb
index 7138bd59..43e74b12 100644
--- a/app/jobs/conference_cfp_update_mail_job.rb
+++ b/app/jobs/conference_cfp_update_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceCfpUpdateMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/jobs/conference_date_update_mail_job.rb b/app/jobs/conference_date_update_mail_job.rb
index 4218d22f..a50cc077 100644
--- a/app/jobs/conference_date_update_mail_job.rb
+++ b/app/jobs/conference_date_update_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceDateUpdateMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/jobs/conference_registration_date_update_mail_job.rb b/app/jobs/conference_registration_date_update_mail_job.rb
index ed7ee084..00864f7a 100644
--- a/app/jobs/conference_registration_date_update_mail_job.rb
+++ b/app/jobs/conference_registration_date_update_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceRegistrationDateUpdateMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/jobs/conference_schedule_update_mail_job.rb b/app/jobs/conference_schedule_update_mail_job.rb
index 02d03352..d500df2c 100644
--- a/app/jobs/conference_schedule_update_mail_job.rb
+++ b/app/jobs/conference_schedule_update_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceScheduleUpdateMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/jobs/conference_venue_update_mail_job.rb b/app/jobs/conference_venue_update_mail_job.rb
index 30203639..f53ef741 100644
--- a/app/jobs/conference_venue_update_mail_job.rb
+++ b/app/jobs/conference_venue_update_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceVenueUpdateMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/jobs/event_comment_mail_job.rb b/app/jobs/event_comment_mail_job.rb
index 36bc9294..bcc46ca7 100644
--- a/app/jobs/event_comment_mail_job.rb
+++ b/app/jobs/event_comment_mail_job.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventCommentMailJob < ApplicationJob
   queue_as :default
 
diff --git a/app/mailers/mailbot.rb b/app/mailers/mailbot.rb
index 63f95a40..d33973aa 100644
--- a/app/mailers/mailbot.rb
+++ b/app/mailers/mailbot.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Mailbot < ActionMailer::Base
   def registration_mail(conference, user)
     mail(to: user.email,
diff --git a/app/models/ability.rb b/app/models/ability.rb
index d6b3ef21..d048311a 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Ability
   include CanCan::Ability
 
@@ -15,7 +17,7 @@ class Ability
 
   # Abilities for not signed in users (guests)
   def not_signed_in
-    can [:index, :conferences], Organization
+    can %i[index conferences], Organization
     can [:index], Conference
     can [:show], Conference do |conference|
       conference.splashpage && conference.splashpage.public == true
@@ -31,20 +33,16 @@ class Ability
 
     # can view Commercials of confirmed Events
     can :show, Commercial, commercialable_type: 'Event', commercialable_id: Event.where(state: 'confirmed').pluck(:id)
-    can [:show, :create], User
+    can %i[show create], User
     unless ENV['OSEM_ICHAIN_ENABLED'] == 'true'
-      can :show, Registration do |registration|
-        registration.new_record?
-      end
+      can :show, Registration, &:new_record?
 
       can [:new, :create], Registration do |registration|
         conference = registration.conference
         conference.registration_open? && registration.new_record? && !conference.registration_limit_exceeded?
       end
 
-      can :show, Event do |event|
-        event.new_record?
-      end
+      can :show, Event, &:new_record?
 
       can [:new, :create], Event do |event|
         event.program.cfp_open? && event.new_record?
@@ -78,8 +76,8 @@ class Ability
     can :index, Organization
     can :index, Ticket
     can :manage, TicketPurchase, user_id: user.id
-    can [:new, :create], Payment, user_id: user.id
-    can [:index, :show], PhysicalTicket, user: user
+    can %i[new create], Payment, user_id: user.id
+    can %i[index show], PhysicalTicket, user: user
 
     can [:new, :create], Booth do |booth|
       booth.new_record? && booth.conference.program.cfps.for_booths.try(:open?)
@@ -89,7 +87,7 @@ class Ability
       booth.users.include?(user)
     end
 
-    can [:create, :destroy], Subscription, user_id: user.id
+    can %i[create destroy], Subscription, user_id: user.id
 
     can [:new, :create], Event do |event|
       event.program.cfp_open? && event.new_record?
@@ -108,7 +106,7 @@ class Ability
       track.new_record? && track.program.cfps.for_tracks.try(:open?)
     end
 
-    can [:index, :show, :restart, :confirm, :withdraw], Track, submitter_id: user.id
+    can %i[index show restart confirm withdraw], Track, submitter_id: user.id
 
     can [:edit, :update], Track do |track|
       user == track.submitter && !(track.accepted? || track.confirmed?)
diff --git a/app/models/admin_ability.rb b/app/models/admin_ability.rb
index 603f499e..03a6470f 100644
--- a/app/models/admin_ability.rb
+++ b/app/models/admin_ability.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AdminAbility
   include CanCan::Ability
 
@@ -28,12 +30,12 @@ class AdminAbility
       conference.registration_open? && !conference.registration_limit_exceeded? || conference.program.speakers.confirmed.include?(user)
     end
 
-    can [:index, :admins], Organization
+    can %i[index admins], Organization
     can :index, Ticket
     can :manage, TicketPurchase, user_id: user.id
-    can [:new, :create], Payment, user_id: user.id
+    can %i[new create], Payment, user_id: user.id
 
-    can [:create, :destroy], Subscription, user_id: user.id
+    can %i[create destroy], Subscription, user_id: user.id
 
     can [:new, :create], Event do |event|
       event.program.cfp_open? && event.new_record?
@@ -45,11 +47,11 @@ class AdminAbility
     can [:destroy], Openid
     can :access, Admin
     can :index, Commercial, commercialable_type: 'Conference'
-    cannot [:edit, :update, :destroy], Question, global: true
+    cannot %i[edit update destroy], Question, global: true
     # for admins
     can :manage, :all if user.is_admin
     # even admin cannot create new users with ICHAIN enabled
-    cannot [:new, :create], User if ENV['OSEM_ICHAIN_ENABLED'] == 'true'
+    cannot %i[new create], User if ENV['OSEM_ICHAIN_ENABLED'] == 'true'
     cannot :revert_object, PaperTrail::Version do |version|
       (version.event == 'create' && %w[Conference User Event].include?(version.item_type))
     end
@@ -67,9 +69,7 @@ class AdminAbility
     end
 
     # Prevent requests for tracks from being destroyed
-    cannot :destroy, Track do |track|
-      track.self_organized?
-    end
+    cannot :destroy, Track, &:self_organized?
     # Can't accept a booth when booth_limit is reached
     cannot :accept, Booth do |booth|
       conference = booth.conference
@@ -92,10 +92,10 @@ class AdminAbility
     org_ids_for_organization_admin = Organization.with_role(:organization_admin, user).pluck(:id)
     conf_ids_for_organization_admin = Conference.where(organization_id: org_ids_for_organization_admin).pluck(:id)
 
-    can [:read, :update, :destroy, :assign_org_admins, :unassign_org_admins, :admins], Organization, id: org_ids_for_organization_admin
+    can %i[read update destroy assign_org_admins unassign_org_admins admins], Organization, id: org_ids_for_organization_admin
     can :new, Conference
     can :manage, Conference, organization_id: org_ids_for_organization_admin
-    can [:index, :show], Role
+    can %i[index show], Role
 
     signed_in_with_organizer_role(user, conf_ids_for_organization_admin)
   end
@@ -108,7 +108,7 @@ class AdminAbility
     track_ids = Track.joins(:program).where('programs.conference_id IN (?)', conf_ids).pluck(:id)
 
     can :manage, Resource, conference_id: conf_ids
-    can [:read, :update, :destroy], Conference, id: conf_ids
+    can %i[read update destroy], Conference, id: conf_ids
     can :manage, Splashpage, conference_id: conf_ids
     can :manage, Contact, conference_id: conf_ids
     can :manage, EmailSettings, conference_id: conf_ids
@@ -163,8 +163,8 @@ class AdminAbility
         role.resource_type == 'Track' && (track_ids.include? role.resource_id)
     end
 
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, item_type: 'User'
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, conference_id: conf_ids
+    can %i[index revert_object revert_attribute], PaperTrail::Version, item_type: 'User'
+    can %i[index revert_object revert_attribute], PaperTrail::Version, conference_id: conf_ids
   end
 
   def signed_in_with_cfp_role(user)
@@ -174,7 +174,7 @@ class AdminAbility
     can :show, Conference do |conf|
       conf_ids_for_cfp.include?(conf.id)
     end
-    can [:index, :show, :update], Resource, conference_id: conf_ids_for_cfp
+    can %i[index show update], Resource, conference_id: conf_ids_for_cfp
     can :manage, Booth, conference_id: conf_ids_for_cfp
     can :manage, Event, program: { conference_id: conf_ids_for_cfp }
     can :manage, EventType, program: { conference_id: conf_ids_for_cfp }
@@ -203,7 +203,7 @@ class AdminAbility
         (Conference.with_role(:cfp, user).pluck(:id).include? role.resource_id)
     end
 
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version,
+    can %i[index revert_object revert_attribute], PaperTrail::Version,
         item_type: %w[Event EventType Track DifficultyLevel EmailSettings Room Cfp Program Comment], conference_id: conf_ids_for_cfp
     can [:index, :revert_object, :revert_attribute], PaperTrail::Version,
         ["item_type = 'Commercial' AND conference_id IN (?) AND (object LIKE '%Event%' OR object_changes LIKE '%Event%')", conf_ids_for_cfp] do |version|
@@ -219,7 +219,7 @@ class AdminAbility
     can :show, Conference do |conf|
       conf_ids_for_info_desk.include?(conf.id)
     end
-    can [:index, :show, :update], Resource, conference_id: conf_ids_for_info_desk
+    can %i[index show update], Resource, conference_id: conf_ids_for_info_desk
     can :manage, Registration, conference_id: conf_ids_for_info_desk
     can :manage, Question, conference_id: conf_ids_for_info_desk
     can :manage, Question do |question|
@@ -240,7 +240,7 @@ class AdminAbility
       role.resource_type == 'Conference' && role.name == 'info_desk' &&
         (Conference.with_role(:info_desk, user).pluck(:id).include? role.resource_id)
     end
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, item_type: 'Registration', conference_id: conf_ids_for_info_desk
+    can %i[index revert_object revert_attribute], PaperTrail::Version, item_type: 'Registration', conference_id: conf_ids_for_info_desk
   end
 
   def signed_in_with_volunteers_coordinator_role(user)
@@ -250,7 +250,7 @@ class AdminAbility
     can :show, Conference do |conf|
       conf_ids_for_volunteers_coordinator.include?(conf.id)
     end
-    can [:index, :show, :update], Resource, conference_id: conf_ids_for_volunteers_coordinator
+    can %i[index show update], Resource, conference_id: conf_ids_for_volunteers_coordinator
     can :manage, Vposition, conference_id: conf_ids_for_volunteers_coordinator
     can :manage, Vday, conference_id: conf_ids_for_volunteers_coordinator
 
@@ -286,9 +286,7 @@ class AdminAbility
 
     can :manage, Track, id: track_ids_for_track_organizer
 
-    cannot [:edit, :update], Track do |track|
-      track.self_organized_and_accepted_or_confirmed?
-    end
+    cannot %i[edit update], Track, &:self_organized_and_accepted_or_confirmed?
 
     # Show Roles in the admin sidebar and allow authorization of the index action
     can [:index, :show], Role do |role|
diff --git a/app/models/ahoy/event.rb b/app/models/ahoy/event.rb
index 74758c47..cf693623 100644
--- a/app/models/ahoy/event.rb
+++ b/app/models/ahoy/event.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Ahoy
   class Event < ApplicationRecord
     self.table_name = 'ahoy_events'
diff --git a/app/models/answer.rb b/app/models/answer.rb
index 6d1bca3c..abada979 100644
--- a/app/models/answer.rb
+++ b/app/models/answer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Answer < ApplicationRecord
   has_many :qanswers
   has_many :questions, through: :qanswers
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
index 10a4cba8..71fbba5b 100644
--- a/app/models/application_record.rb
+++ b/app/models/application_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
 end
diff --git a/app/models/booth.rb b/app/models/booth.rb
index e64a230a..7d2b4098 100644
--- a/app/models/booth.rb
+++ b/app/models/booth.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Booth < ApplicationRecord
   include ActiveRecord::Transitions
   has_paper_trail ignore: [:updated_at], meta: { conference_id: :conference_id }
@@ -41,28 +43,28 @@ class Booth < ApplicationRecord
     state :confirmed
 
     event :restart do
-      transitions to: :new, from: [:withdrawn, :rejected, :canceled]
+      transitions to: :new, from: %i[withdrawn rejected canceled]
     end
     event :withdraw do
-      transitions to: :withdrawn, from: [:new, :to_accept, :accepted, :to_reject, :rejected, :confirmed]
+      transitions to: :withdrawn, from: %i[new to_accept accepted to_reject rejected confirmed]
     end
     event :confirm do
       transitions to: :confirmed, from: [:accepted]
     end
     event :to_accept do
-      transitions to: :to_accept, from: [:new, :to_reject]
+      transitions to: :to_accept, from: %i[new to_reject]
     end
     event :to_reject do
-      transitions to: :to_reject, from: [:new, :to_accept]
+      transitions to: :to_reject, from: %i[new to_accept]
     end
     event :accept do
-      transitions to: :accepted, from: [:new, :to_accept]
+      transitions to: :accepted, from: %i[new to_accept]
     end
     event :reject do
-      transitions to: :rejected, from: [:new, :to_reject]
+      transitions to: :rejected, from: %i[new to_reject]
     end
     event :cancel do
-      transitions to: :canceled, from: [:accepted, :rejected, :to_accept, :to_reject, :confirmed]
+      transitions to: :canceled, from: %i[accepted rejected to_accept to_reject confirmed]
     end
   end
 
diff --git a/app/models/booth_request.rb b/app/models/booth_request.rb
index f57c712e..5cce46a1 100644
--- a/app/models/booth_request.rb
+++ b/app/models/booth_request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BoothRequest < ApplicationRecord
   belongs_to :booth
   belongs_to :user
diff --git a/app/models/campaign.rb b/app/models/campaign.rb
index 103274a0..3e02ccb4 100644
--- a/app/models/campaign.rb
+++ b/app/models/campaign.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Campaign < ApplicationRecord
   validates :name, :utm_campaign, presence: true
 
@@ -66,11 +68,11 @@ class Campaign < ApplicationRecord
   # * +Hash+ -> parameter => value
   def get_parameters
     conditions = {}
-    conditions[:utm_source] = self[:utm_source] unless self[:utm_source].blank?
-    conditions[:utm_medium] = self[:utm_medium] unless self[:utm_medium].blank?
-    conditions[:utm_term] = self[:utm_term] unless self[:utm_term].blank?
-    conditions[:utm_content] = self[:utm_content] unless self[:utm_content].blank?
-    conditions[:utm_campaign] = self[:utm_campaign] unless self[:utm_campaign].blank?
+    conditions[:utm_source] = self[:utm_source] if self[:utm_source].present?
+    conditions[:utm_medium] = self[:utm_medium] if self[:utm_medium].present?
+    conditions[:utm_term] = self[:utm_term] if self[:utm_term].present?
+    conditions[:utm_content] = self[:utm_content] if self[:utm_content].present?
+    conditions[:utm_campaign] = self[:utm_campaign] if self[:utm_campaign].present?
     conditions
   end
 end
diff --git a/app/models/cfp.rb b/app/models/cfp.rb
index 5105a6bd..8014df18 100644
--- a/app/models/cfp.rb
+++ b/app/models/cfp.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 # cannot delete program if there are events submitted
 
 class Cfp < ApplicationRecord
-  TYPES = %w(events booths tracks).freeze
+  TYPES = %w[events booths tracks].freeze
 
   has_paper_trail ignore: [:updated_at], meta: { conference_id: :conference_id }
   belongs_to :program
@@ -27,11 +29,11 @@ class Cfp < ApplicationRecord
   # * +True+ -> If cfp dates is updated and all other parameters are set
   # * +False+ -> Either cfp date is not updated or one or more parameter is not set
   def notify_on_cfp_date_update?
-    !end_date.blank? && !start_date.blank?\
+    end_date.present? && start_date.present?\
     && (start_date_changed? || end_date_changed?)\
     && program.conference.email_settings.send_on_cfp_dates_updated\
-    && !program.conference.email_settings.cfp_dates_updated_subject.blank?\
-    && !program.conference.email_settings.cfp_dates_updated_body.blank?
+    && program.conference.email_settings.cfp_dates_updated_subject.present?\
+    && program.conference.email_settings.cfp_dates_updated_body.present?
   end
 
   ##
@@ -106,20 +108,22 @@ class Cfp < ApplicationRecord
   private
 
   def before_end_of_conference
-    if program && program.conference && program.conference.end_date && end_date && (end_date > program.conference.end_date)
+    if program&.conference && program.conference.end_date && end_date && (end_date > program.conference.end_date)
       errors
-      .add(:end_date, "can't be after the conference end date (#{program.conference.end_date})")
+        .add(:end_date, "can't be after the conference end date (#{program.conference.end_date})")
     end
 
-    if program && program.conference && program.conference.end_date && start_date && (start_date > program.conference.end_date)
+    if program&.conference && program.conference.end_date && start_date && (start_date > program.conference.end_date)
       errors
-      .add(:start_date, "can't be after the conference end date (#{program.conference.end_date})")
+        .add(:start_date, "can't be after the conference end date (#{program.conference.end_date})")
     end
   end
 
   def start_after_end_date
-    errors
-    .add(:start_date, "can't be after the end date") if start_date && end_date && start_date > end_date
+    if start_date && end_date && start_date > end_date
+      errors
+        .add(:start_date, "can't be after the end date")
+    end
   end
 
   def conference_id
diff --git a/app/models/comment.rb b/app/models/comment.rb
index 535eea57..38a1c791 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,19 +1,21 @@
+# frozen_string_literal: true
+
 class Comment < ApplicationRecord
-  acts_as_nested_set scope: %i(commentable_id commentable_type)
+  acts_as_nested_set scope: %i[commentable_id commentable_type]
   validates :body, presence: true
   validates :user, presence: true
   after_create :send_notification
 
   # NOTE: install the acts_as_votable plugin if you
   # want user to vote on the quality of comments.
-  #acts_as_votable
+  # acts_as_votable
 
   belongs_to :commentable, counter_cache: true, polymorphic: true
 
   # NOTE: Comments belong to a user
   belongs_to :user
 
-  has_paper_trail on: %i(create destroy), meta: { conference_id: :conference_id }
+  has_paper_trail on: %i[create destroy], meta: { conference_id: :conference_id }
 
   # Helper class method that allows you to build a comment
   # by passing a commentable object, a user_id, and comment text
@@ -25,7 +27,7 @@ class Comment < ApplicationRecord
       user_id: user_id
   end
 
-  #helper method to check if a comment has children
+  # helper method to check if a comment has children
   def has_children?
     children.any?
   end
diff --git a/app/models/commercial.rb b/app/models/commercial.rb
index ad9597e4..2b4e1621 100644
--- a/app/models/commercial.rb
+++ b/app/models/commercial.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Commercial < ApplicationRecord
   require 'oembed'
 
@@ -6,7 +8,7 @@ class Commercial < ApplicationRecord
   has_paper_trail ignore: [:updated_at], meta: { conference_id: :conference_id }
 
   validates :url, presence: true, uniqueness: { scope: :commercialable }
-  validates :url, format: URI::regexp(%w(http https))
+  validates :url, format: URI.regexp(%w[http https])
 
   validate :valid_url
 
@@ -36,9 +38,7 @@ class Commercial < ApplicationRecord
       errors[:no_event] << id && next unless event
 
       commercial = event.commercials.new(url: url)
-      unless commercial.save
-        errors[:validation_errors] << "Could not create commercial for event with ID #{event.id} (" + commercial.errors.full_messages.to_sentence + ')'
-      end
+      errors[:validation_errors] << "Could not create commercial for event with ID #{event.id} (" + commercial.errors.full_messages.to_sentence + ')' unless commercial.save
     end
     errors
   end
@@ -47,9 +47,7 @@ class Commercial < ApplicationRecord
 
   def valid_url
     result = Commercial.render_from_url(url)
-    if result[:error]
-      errors.add(:base, result[:error])
-    end
+    errors.add(:base, result[:error]) if result[:error]
   end
 
   def self.register_provider
@@ -58,12 +56,12 @@ class Commercial < ApplicationRecord
     speakerdeck << 'http://speakerdeck.com/*'
 
     OEmbed::Providers.register(
-        OEmbed::Providers::Youtube,
-        OEmbed::Providers::Vimeo,
-        OEmbed::Providers::Slideshare,
-        OEmbed::Providers::Flickr,
-        OEmbed::Providers::Instagram,
-        speakerdeck
+      OEmbed::Providers::Youtube,
+      OEmbed::Providers::Vimeo,
+      OEmbed::Providers::Slideshare,
+      OEmbed::Providers::Flickr,
+      OEmbed::Providers::Instagram,
+      speakerdeck
     )
   end
 
diff --git a/app/models/concerns/revision_count.rb b/app/models/concerns/revision_count.rb
index 71789f34..4b395367 100644
--- a/app/models/concerns/revision_count.rb
+++ b/app/models/concerns/revision_count.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module RevisionCount
   extend ActiveSupport::Concern
 
diff --git a/app/models/conference.rb b/app/models/conference.rb
index 81e9ec32..50594039 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Conference < ApplicationRecord
   include RevisionCount
   require 'uri'
@@ -12,7 +14,7 @@ class Conference < ApplicationRecord
 
   belongs_to :organization
 
-  has_paper_trail ignore: %i(updated_at guid revision events_per_week), meta: { conference_id: :id }
+  has_paper_trail ignore: %i[updated_at guid revision events_per_week], meta: { conference_id: :id }
 
   has_and_belongs_to_many :questions
 
@@ -91,7 +93,7 @@ class Conference < ApplicationRecord
   after_create :create_free_ticket
   after_update :delete_event_schedules
 
-  enum ticket_layout: [:portrait, :landscape]
+  enum ticket_layout: %i[portrait landscape]
 
   ##
   # Checks if the user is registered to the conference
@@ -101,7 +103,7 @@ class Conference < ApplicationRecord
   # ====Returns
   # * +false+ -> If the user is registered
   # * +true+ - If the user isn't registered
-  def user_registered? user
+  def user_registered?(user)
     user.present? && registrations.where(user_id: user.id).count > 0
   end
 
@@ -112,8 +114,8 @@ class Conference < ApplicationRecord
     if start_hour_changed? || end_hour_changed?
       event_schedules = program.event_schedules.select do |event_schedule|
         event_schedule.start_time.hour < start_hour ||
-        event_schedule.end_time.hour > end_hour ||
-        (event_schedule.end_time.hour == end_hour && event_schedule.end_time.minute > 0)
+          event_schedule.end_time.hour > end_hour ||
+          (event_schedule.end_time.hour == end_hour && event_schedule.end_time.minute > 0)
       end
       event_schedules.each(&:destroy)
     end
@@ -151,7 +153,7 @@ class Conference < ApplicationRecord
   def get_submissions_per_week
     result = []
 
-    if program && program.cfp && program.events
+    if program&.cfp && program.events
       submissions = program.events.select(:week).group(:week).order(:week).count
       start_week = program.cfp.start_week
       weeks = program.cfp.weeks
@@ -168,7 +170,7 @@ class Conference < ApplicationRecord
   #  * +Array+ -> e.g. 'Submitted' => [0, 3, 3, 5]  -> first week 0 events, second week 3 events.
   def get_submissions_data
     result = {}
-    if program && program.cfp && program.events
+    if program&.cfp && program.events
       result = get_events_per_week_by_state
 
       start_week = program.cfp.start_week
@@ -196,9 +198,9 @@ class Conference < ApplicationRecord
     result = []
 
     if registrations &&
-        registration_period &&
-        registration_period.start_date &&
-        registration_period.end_date
+       registration_period &&
+       registration_period.start_date &&
+       registration_period.end_date
 
       reg = registrations.group(:week).order(:week).count
       start_week = get_registration_start_week
@@ -269,11 +271,10 @@ class Conference < ApplicationRecord
   def registration_weeks
     result = 0
     weeks = 0
-    if registration_period &&
-        registration_period.start_date &&
-        registration_period.end_date
+    if registration_period&.start_date &&
+       registration_period.end_date
       weeks = Date.new(registration_period.start_date.year, 12, 31)
-          .strftime('%W').to_i
+                  .strftime('%W').to_i
 
       result = get_registration_end_week - get_registration_start_week + 1
     end
@@ -343,7 +344,7 @@ class Conference < ApplicationRecord
       tracks: tracks_set?,
       event_types: event_types_set?,
       difficulty_levels: difficulty_levels_set?,
-      splashpage: splashpage && splashpage.public?
+      splashpage: splashpage&.public?
     }
 
     result.update(
@@ -370,8 +371,8 @@ class Conference < ApplicationRecord
   # * +hash+ -> user: submissions
   def get_top_submitter(limit = 5)
     submitter = EventUser.joins(:event).select(:user_id)
-        .where('event_role = ? and program_id = ?', 'submitter', Conference.find(id).program.id)
-        .limit(limit).group(:user_id)
+                         .where('event_role = ? and program_id = ?', 'submitter', Conference.find(id).program.id)
+                         .limit(limit).group(:user_id)
     counter = submitter.order('count_all desc').count(:all)
     Conference.calculate_user_submission_hash(submitter, counter)
   end
@@ -595,12 +596,12 @@ class Conference < ApplicationRecord
   # * +ActiveRecord+
   def self.get_active_conferences_for_dashboard
     result = Conference.where('start_date > ?', Time.now)
-        .select('id, short_title, color, start_date, organization_id')
+                       .select('id, short_title, color, start_date, organization_id')
 
     if result.empty?
       result = Conference
-          .select('id, short_title, color, start_date, organization_id').limit(2)
-          .order(start_date: :desc)
+               .select('id, short_title, color, start_date, organization_id').limit(2)
+               .order(start_date: :desc)
     end
     result
   end
@@ -671,9 +672,7 @@ class Conference < ApplicationRecord
         result[state.name] = count
       end
 
-      unless conference.events_per_week
-        conference.events_per_week = {}
-      end
+      conference.events_per_week = {} unless conference.events_per_week
 
       # Write to database
       conference.events_per_week[week] = result
@@ -785,7 +784,7 @@ class Conference < ApplicationRecord
   # the color. We make use of big prime numbers to avoid repetition and to make
   # consecutive colors clearly different.
   def next_color_component(component, i)
-    big_prime_numbers = {r: 113, g: 67, b: 151}
+    big_prime_numbers = { r: 113, g: 67, b: 151 }
     ((i * big_prime_numbers[component]) % 239 + 16).to_s(16)
   end
 
@@ -861,12 +860,9 @@ class Conference < ApplicationRecord
     # Completed weeks
     events_per_week.each do |week, values|
       values.each do |state, value|
-        if %i(confirmed unconfirmed).include?(state)
-          unless result[state.to_s.capitalize]
-            result[state.to_s.capitalize] = {}
-          end
-          result[state.to_s.capitalize][week.strftime('%W').to_i] = value
-        end
+        next unless %i[confirmed unconfirmed].include?(state)
+        result[state.to_s.capitalize] = {} unless result[state.to_s.capitalize]
+        result[state.to_s.capitalize][week.strftime('%W').to_i] = value
       end
     end
 
@@ -923,9 +919,7 @@ class Conference < ApplicationRecord
   # * +Array+
   def pad_left(first_week, start_week)
     left = []
-    if first_week > start_week
-      left = Array.new(first_week - start_week - 1, 0)
-    end
+    left = Array.new(first_week - start_week - 1, 0) if first_week > start_week
     left
   end
 
@@ -938,9 +932,7 @@ class Conference < ApplicationRecord
   def assert_keys_are_continuously(hash)
     keys = hash.keys
     (keys.min..keys.max).each do |key|
-      unless hash[key]
-        hash[key] = 0
-      end
+      hash[key] = 0 unless hash[key]
     end
     Hash[hash.sort]
   end
@@ -1048,12 +1040,11 @@ class Conference < ApplicationRecord
 
     grouped.each do |event|
       object = event.send(symbol)
-      if object
-        result[object.title] = {
-          'value' => counter[object.id],
-          'color' => object.color
-        }
-      end
+      next unless object
+      result[object.title] = {
+        'value' => counter[object.id],
+        'color' => object.color
+      }
     end
     result
   end
@@ -1067,12 +1058,11 @@ class Conference < ApplicationRecord
   def calculate_track_distribution_hash(tracks_grouped, tracks_counter)
     result = {}
     tracks_grouped.each do |event|
-      if event.track
-        result[event.track.name] = {
-          'value' => tracks_counter[event.track_id],
-          'color' => event.track.color
-        }
-      end
+      next unless event.track
+      result[event.track.name] = {
+        'value' => tracks_counter[event.track_id],
+        'color' => event.track.color
+      }
     end
     result
   end
@@ -1127,10 +1117,10 @@ class Conference < ApplicationRecord
     result = {}
     states.each do |key, value|
       result[key.capitalize] =
-          {
-            'value' => value,
-            'color' => Event.get_state_color(key)
-          }
+        {
+          'value' => value,
+          'color' => Event.get_state_color(key)
+        }
     end
     result
   end
@@ -1145,9 +1135,7 @@ class Conference < ApplicationRecord
     counter.each do |key, value|
       # make PG happy by including the user_id in ORDER
       submitter = submitters.where(user_id: key).order(:user_id).first
-      if submitter
-        result[submitter.user] = value
-      end
+      result[submitter.user] = value if submitter
     end
     result
   end
@@ -1165,9 +1153,9 @@ class Conference < ApplicationRecord
   #
   def generate_guid
     guid = SecureRandom.urlsafe_base64
-#     begin
-#       guid = SecureRandom.urlsafe_base64
-#     end while User.where(:guid => guid).exists?
+    #     begin
+    #       guid = SecureRandom.urlsafe_base64
+    #     end while User.where(:guid => guid).exists?
     self.guid = guid
   end
 
@@ -1175,19 +1163,17 @@ class Conference < ApplicationRecord
   # Adds a random color to the conference
   #
   def add_color
-    unless color
-      self.color = get_color
-    end
+    self.color = get_color unless color
   end
 
   def get_color
-    %w(
-        #000000 #0000FF #00FF00 #FF0000 #FFFF00 #9900CC
-        #CC0066 #00FFFF #FF00FF #C0C0C0 #00008B #FFD700
-        #FFA500 #FF1493 #FF00FF #F0FFFF #EE82EE #D2691E
-        #C0C0C0 #A52A2A #9ACD32 #9400D3 #8B008B #8B0000
-        #87CEEB #808080 #800080 #008B8B #006400
-      ).sample
+    %w[
+      #000000 #0000FF #00FF00 #FF0000 #FFFF00 #9900CC
+      #CC0066 #00FFFF #FF00FF #C0C0C0 #00008B #FFD700
+      #FFA500 #FF1493 #FF00FF #F0FFFF #EE82EE #D2691E
+      #C0C0C0 #A52A2A #9ACD32 #9400D3 #8B008B #8B0000
+      #87CEEB #808080 #800080 #008B8B #006400
+    ].sample
   end
 
   # Calculates items per week from a hash.
@@ -1206,9 +1192,7 @@ class Conference < ApplicationRecord
 
     items.each do |key, value|
       # Padding
-      if last_key < (key.to_i - 1)
-        result += Array.new(key.to_i - last_key - 1, sum)
-      end
+      result += Array.new(key.to_i - last_key - 1, sum) if last_key < (key.to_i - 1)
 
       sum += value
       result.push(sum)
@@ -1216,9 +1200,7 @@ class Conference < ApplicationRecord
     end
 
     # Padding right
-    if result.length < weeks
-      result += Array.new(weeks - result.length, sum)
-    end
+    result += Array.new(weeks - result.length, sum) if result.length < weeks
 
     result
   end
diff --git a/app/models/contact.rb b/app/models/contact.rb
index dd7196dd..f7db79e2 100644
--- a/app/models/contact.rb
+++ b/app/models/contact.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Contact < ApplicationRecord
   has_paper_trail on: [:update], ignore: [:updated_at], meta: { conference_id: :conference_id }
 
@@ -6,7 +8,7 @@ class Contact < ApplicationRecord
   validates :conference, presence: true
   # Conferences only have one contact
   validates :facebook, :twitter, :googleplus, :instagram, :mastodon,
-            format: URI::regexp(%w(http https)), allow_blank: true
+            format: URI.regexp(%w[http https]), allow_blank: true
 
   def has_social_media?
     return true if facebook.present? || twitter.present? || googleplus.present? || instagram.present? || mastodon.present? || email.present?
diff --git a/app/models/difficulty_level.rb b/app/models/difficulty_level.rb
index d9a09e22..98186693 100644
--- a/app/models/difficulty_level.rb
+++ b/app/models/difficulty_level.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DifficultyLevel < ApplicationRecord
   belongs_to :program, touch: true
   has_many :events, dependent: :nullify
diff --git a/app/models/email_settings.rb b/app/models/email_settings.rb
index 2c593b96..b8b682bb 100644
--- a/app/models/email_settings.rb
+++ b/app/models/email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailSettings < ApplicationRecord
   belongs_to :conference
 
@@ -11,12 +13,15 @@ class EmailSettings < ApplicationRecord
       'conference_start_date' => conference.start_date,
       'conference_end_date' => conference.end_date,
       'registrationlink' => Rails.application.routes.url_helpers.conference_conference_registration_url(
-                            conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')),
+        conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')
+      ),
       'conference_splash_link' => Rails.application.routes.url_helpers.conference_url(
-                                  conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')),
+        conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')
+      ),
 
       'schedule_link' => Rails.application.routes.url_helpers.conference_schedule_url(
-                         conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000'))
+        conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')
+      )
     }
 
     if conference.program.cfp
@@ -43,12 +48,11 @@ class EmailSettings < ApplicationRecord
     if event
       h['eventtitle'] = event.title
       h['proposalslink'] = Rails.application.routes.url_helpers.conference_program_proposals_url(
-                           conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000'))
+        conference.short_title, host: (ENV['OSEM_HOSTNAME'] || 'localhost:3000')
+      )
     end
 
-    if booth
-      h['booth_title'] = booth.title
-    end
+    h['booth_title'] = booth.title if booth
     h
   end
 
@@ -71,8 +75,8 @@ class EmailSettings < ApplicationRecord
 
   def parse_template(text, values)
     values.each do |key, value|
-      if value.kind_of?(Date)
-        text = text.gsub "{#{key}}", value.strftime('%Y-%m-%d') unless text.blank?
+      if value.is_a?(Date)
+        text = text.gsub "{#{key}}", value.strftime('%Y-%m-%d') if text.present?
       else
         text = text.gsub "{#{key}}", value unless text.blank? || value.blank?
       end
diff --git a/app/models/event.rb b/app/models/event.rb
index 943572eb..9d7d80aa 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class Event < ApplicationRecord
   include ActiveRecord::Transitions
   include RevisionCount
-  has_paper_trail on: [:create, :update], ignore: [:updated_at, :guid, :week], meta: { conference_id: :conference_id }
+  has_paper_trail on: %i[create update], ignore: %i[updated_at guid week], meta: { conference_id: :conference_id }
 
   acts_as_commentable
 
@@ -61,10 +63,10 @@ class Event < ApplicationRecord
     state :rejected
 
     event :restart do
-      transitions to: :new, from: [:rejected, :withdrawn, :canceled]
+      transitions to: :new, from: %i[rejected withdrawn canceled]
     end
     event :withdraw do
-      transitions to: :withdrawn, from: [:new, :unconfirmed, :confirmed]
+      transitions to: :withdrawn, from: %i[new unconfirmed confirmed]
     end
     event :accept do
       transitions to: :unconfirmed, from: [:new], on_transition: :process_acceptance
@@ -73,7 +75,7 @@ class Event < ApplicationRecord
       transitions to: :confirmed, from: :unconfirmed, on_transition: :process_confirmation
     end
     event :cancel do
-      transitions to: :canceled, from: [:unconfirmed, :confirmed]
+      transitions to: :canceled, from: %i[unconfirmed confirmed]
     end
     event :reject do
       transitions to: :rejected, from: [:new], on_transition: :process_rejection
@@ -108,7 +110,7 @@ class Event < ApplicationRecord
   # ====Returns
   # * +true+ -> If the event has votes (optionally, by the user)
   # * +false+ -> If the event does not have any votes (optionally, by the user)
-  def voted?(user=nil)
+  def voted?(user = nil)
     return votes.where(user: user).any? if user
 
     votes.any?
@@ -128,9 +130,7 @@ class Event < ApplicationRecord
   def speakers_ordered
     speakers_list = speakers.to_a
 
-    if speakers_list.reject! { |speaker| speaker == submitter }
-      speakers_list.unshift(submitter)
-    end
+    speakers_list.unshift(submitter) if speakers_list.reject! { |speaker| speaker == submitter }
 
     speakers_list
   end
@@ -141,28 +141,26 @@ class Event < ApplicationRecord
 
   def process_confirmation
     if program.conference.email_settings.send_on_confirmed_without_registration? &&
-        program.conference.email_settings.confirmed_without_registration_body &&
-        program.conference.email_settings.confirmed_without_registration_subject
-      if program.conference.registrations.where(user_id: submitter.id).first.nil?
-        Mailbot.confirm_reminder_mail(self).deliver_later
-      end
+       program.conference.email_settings.confirmed_without_registration_body &&
+       program.conference.email_settings.confirmed_without_registration_subject
+      Mailbot.confirm_reminder_mail(self).deliver_later if program.conference.registrations.where(user_id: submitter.id).first.nil?
     end
   end
 
   def process_acceptance(options)
     if program.conference.email_settings.send_on_accepted &&
-        program.conference.email_settings.accepted_body &&
-        program.conference.email_settings.accepted_subject &&
-        !options[:send_mail].blank?
+       program.conference.email_settings.accepted_body &&
+       program.conference.email_settings.accepted_subject &&
+       options[:send_mail].present?
       Mailbot.acceptance_mail(self).deliver_later
     end
   end
 
   def process_rejection(options)
     if program.conference.email_settings.send_on_rejected &&
-        program.conference.email_settings.rejected_body &&
-        program.conference.email_settings.rejected_subject &&
-        !options[:send_mail].blank?
+       program.conference.email_settings.rejected_body &&
+       program.conference.email_settings.rejected_subject &&
+       options[:send_mail].present?
       Mailbot.rejection_mail(self).deliver_later
     end
   end
@@ -186,28 +184,26 @@ class Event < ApplicationRecord
 
   def update_state(transition, mail = false, subject = false, send_mail = false, send_mail_param)
     alert = ''
-    if mail && send_mail_param && subject && send_mail
-      alert = 'Update Email Subject before Sending Mails'
-    end
-      begin
-        if mail
-          send(transition,
-               send_mail: send_mail_param)
-        else
-          send(transition)
-        end
-        save
-        # If the event was previously scheduled, and then withdrawn or cancelled
-        # its event_schedule will have enabled set to false
-        # If the event is now confirmed again, we want it to be available for scheduling
-        Rails.logger.debug "transition is #{transition}"
-        if transition == :confirm
-          Rails.logger.debug "schedules #{EventSchedule.unscoped.where(event: self, enabled: false)}"
-          EventSchedule.unscoped.where(event: self, enabled: false).destroy_all
-        end
-      rescue Transitions::InvalidTransition => e
-        alert = "Update state failed. #{e.message}"
+    alert = 'Update Email Subject before Sending Mails' if mail && send_mail_param && subject && send_mail
+    begin
+      if mail
+        send(transition,
+             send_mail: send_mail_param)
+      else
+        send(transition)
       end
+      save
+      # If the event was previously scheduled, and then withdrawn or cancelled
+      # its event_schedule will have enabled set to false
+      # If the event is now confirmed again, we want it to be available for scheduling
+      Rails.logger.debug "transition is #{transition}"
+      if transition == :confirm
+        Rails.logger.debug "schedules #{EventSchedule.unscoped.where(event: self, enabled: false)}"
+        EventSchedule.unscoped.where(event: self, enabled: false).destroy_all
+      end
+    rescue Transitions::InvalidTransition => e
+      alert = "Update state failed. #{e.message}"
+    end
     alert
   end
 
@@ -227,10 +223,10 @@ class Event < ApplicationRecord
     {
       registered: speakers.all? { |speaker| program.conference.user_registered? speaker },
       commercials: commercials.any?,
-      biographies: speakers.all? { |speaker| !speaker.biography.blank? },
-      subtitle: !subtitle.blank?,
-      track: (!track.blank? unless program.tracks.empty?),
-      difficulty_level: !difficulty_level.blank?,
+      biographies: speakers.all? { |speaker| speaker.biography.present? },
+      subtitle: subtitle.present?,
+      track: (track.present? unless program.tracks.empty?),
+      difficulty_level: difficulty_level.present?,
       title: true,
       abstract: true
     }.with_indifferent_access
@@ -266,9 +262,7 @@ class Event < ApplicationRecord
     event_schedules.find_by(schedule_id: selected_schedule_id).try(:start_time)
   end
 
-  def conference
-    program.conference
-  end
+  delegate :conference, to: :program
 
   private
 
@@ -309,9 +303,11 @@ class Event < ApplicationRecord
   end
 
   def before_end_of_conference
-    errors
-        .add(:created_at, "can't be after the conference end date!") if program.conference && program.conference.end_date &&
-        (Date.today > program.conference.end_date)
+    if program.conference&.end_date &&
+       (Date.today > program.conference.end_date)
+      errors
+        .add(:created_at, "can't be after the conference end date!")
+    end
   end
 
   def conference_id
@@ -322,7 +318,7 @@ class Event < ApplicationRecord
   # Allow only confirmed tracks that belong to the same program as the event
   #
   def valid_track
-    return unless track && track.program && program
+    return unless track&.program && program
     errors.add(:track, 'is invalid') unless track.confirmed? && track.program == program
   end
 
diff --git a/app/models/event_schedule.rb b/app/models/event_schedule.rb
index 9d59713d..f4d26c17 100644
--- a/app/models/event_schedule.rb
+++ b/app/models/event_schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventSchedule < ApplicationRecord
   default_scope { where(enabled: true) }
   belongs_to :schedule
@@ -71,13 +73,9 @@ class EventSchedule < ApplicationRecord
   def during_track
     return unless event.try(:track) && start_time
 
-    if event.track.try(:start_date) && event.track.start_date > start_time
-      errors.add(:start_time, "can't be before the track's start date (#{event.track.start_date})")
-    end
+    errors.add(:start_time, "can't be before the track's start date (#{event.track.start_date})") if event.track.try(:start_date) && event.track.start_date > start_time
 
-    if event.track.try(:end_date) && event.track.end_date + 1.day < end_time
-      errors.add(:end_time, "can't be after the track's end date (#{event.track.end_date})")
-    end
+    errors.add(:end_time, "can't be after the track's end date (#{event.track.end_date})") if event.track.try(:end_date) && event.track.end_date + 1.day < end_time
   end
 
   ##
diff --git a/app/models/event_type.rb b/app/models/event_type.rb
index 4b19621b..7de162ed 100644
--- a/app/models/event_type.rb
+++ b/app/models/event_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventType < ApplicationRecord
   belongs_to :program, touch: true
   has_many :events, dependent: :restrict_with_error
@@ -6,7 +8,7 @@ class EventType < ApplicationRecord
                   ignore: %i[updated_at]
 
   validates :title, presence: true
-  validates :length, numericality: {greater_than: 0}
+  validates :length, numericality: { greater_than: 0 }
   validates :minimum_abstract_length, presence: true
   validates :maximum_abstract_length, presence: true
   validate :length_step
diff --git a/app/models/event_user.rb b/app/models/event_user.rb
index 85e5f8d8..fd1baa2d 100644
--- a/app/models/event_user.rb
+++ b/app/models/event_user.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 class EventUser < ApplicationRecord
   # TODO: Do we need these roles?
-  ROLES = [%w[Speaker speaker], %w[Submitter submitter], %w[Moderator moderator]]
+  ROLES = [%w[Speaker speaker], %w[Submitter submitter], %w[Moderator moderator]].freeze
 
   belongs_to :event, touch: true
   belongs_to :user
diff --git a/app/models/events_registration.rb b/app/models/events_registration.rb
index 6539064e..735df2a7 100644
--- a/app/models/events_registration.rb
+++ b/app/models/events_registration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventsRegistration < ApplicationRecord
   belongs_to :registration
   belongs_to :event
diff --git a/app/models/lodging.rb b/app/models/lodging.rb
index 50feaf41..2f7a87ad 100644
--- a/app/models/lodging.rb
+++ b/app/models/lodging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Lodging < ApplicationRecord
   belongs_to :conference
 
diff --git a/app/models/openid.rb b/app/models/openid.rb
index b0f45f0c..feaa6a9d 100644
--- a/app/models/openid.rb
+++ b/app/models/openid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Openid < ApplicationRecord
   belongs_to :user
   validates :provider, :uid, :email, presence: true
diff --git a/app/models/organization.rb b/app/models/organization.rb
index 1e3974de..96a17bfa 100644
--- a/app/models/organization.rb
+++ b/app/models/organization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Organization < ApplicationRecord
   resourcify :roles, dependent: :delete_all
 
diff --git a/app/models/payment.rb b/app/models/payment.rb
index 3938dcb6..a7e9e22a 100644
--- a/app/models/payment.rb
+++ b/app/models/payment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Payment < ApplicationRecord
   has_many :ticket_purchases
   belongs_to :user
@@ -32,7 +34,6 @@ class Payment < ApplicationRecord
     self.authorization_code = gateway_response[:id]
     self.status = 'success'
     true
-
   rescue Stripe::StripeError => error
     errors.add(:base, error.message)
     self.status = 'failure'
diff --git a/app/models/physical_ticket.rb b/app/models/physical_ticket.rb
index e98646b0..2493cbbe 100644
--- a/app/models/physical_ticket.rb
+++ b/app/models/physical_ticket.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PhysicalTicket < ApplicationRecord
   belongs_to :ticket_purchase
   has_one :ticket, through: :ticket_purchase
diff --git a/app/models/program.rb b/app/models/program.rb
index 14554786..5d6fe426 100644
--- a/app/models/program.rb
+++ b/app/models/program.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # cannot delete program if there are events submitted
 
 class Program < ApplicationRecord
@@ -42,7 +44,7 @@ class Program < ApplicationRecord
   has_many :event_schedules, through: :events
 
   has_many :event_users, through: :events
-  has_many :program_events_speakers, -> {where(event_role: 'speaker')}, through: :events, source: :event_users
+  has_many :program_events_speakers, -> { where(event_role: 'speaker') }, through: :events, source: :event_users
   has_many :speakers, -> { distinct }, through: :program_events_speakers, source: :user do
     def confirmed
       joins(:events).where(events: { state: :confirmed })
@@ -61,7 +63,7 @@ class Program < ApplicationRecord
   accepts_nested_attributes_for :tracks, reject_if: proc { |r| r['name'].blank? }, allow_destroy: true
   accepts_nested_attributes_for :difficulty_levels, allow_destroy: true
 
-#   validates :conference_id, presence: true, uniqueness: true
+  #   validates :conference_id, presence: true, uniqueness: true
   validates :rating, numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: 10, only_integer: true }
   validates :schedule_interval, numericality: { greater_than_or_equal_to: 5, less_than_or_equal_to: 60 }, presence: true
   validate :schedule_interval_divisor_60
@@ -80,7 +82,7 @@ class Program < ApplicationRecord
     tracks.self_organized.confirmed.order(start_date: :asc).each do |track|
       event_schedules += track.selected_schedule.event_schedules.order(start_time: :asc) if track.selected_schedule
     end
-    event_schedules.sort_by(&:start_time) if event_schedules
+    event_schedules&.sort_by(&:start_time)
   end
 
   ##
@@ -154,11 +156,11 @@ class Program < ApplicationRecord
     # do not notify if the schedule is not public
     return false unless schedule_public
     # do not notify unless the mail content is set up
-    (!conference.email_settings.program_schedule_public_subject.blank? && !conference.email_settings.program_schedule_public_body.blank?)
+    (conference.email_settings.program_schedule_public_subject.present? && conference.email_settings.program_schedule_public_body.present?)
   end
 
   def languages_list
-    languages.split(',').map {|l| ISO_639.find(l).english_name} if languages.present?
+    languages.split(',').map { |l| ISO_639.find(l).english_name } if languages.present?
   end
 
   ##
@@ -224,16 +226,16 @@ class Program < ApplicationRecord
   # Check if languages string has the right format. Used as validation.
   #
   def check_languages_format
-    return unless languages.present?
+    return if languages.blank?
     # All white spaces are removed to allow languages to be separated by ',' and ', '. The languages string without spaces is saved
     self.languages = languages.delete(' ').downcase
-    errors.add(:languages, 'must be two letters separated by commas') && return unless
-    languages.match(/^$|(\A[a-z][a-z](,[a-z][a-z])*\z)/).present?
+    errors.add(:languages, 'must be two letters separated by commas') && return if
+    languages.match(/^$|(\A[a-z][a-z](,[a-z][a-z])*\z)/).blank?
     languages_array = languages.split(',')
     # We check that languages are not repeated
     errors.add(:languages, "can't be repeated") && return unless languages_array.uniq!.nil?
     # We check if every language is a valid ISO 639-1 language
-    errors.add(:languages, 'must be ISO 639-1 valid codes') unless languages_array.select{ |x| ISO_639.find(x).nil? }.empty?
+    errors.add(:languages, 'must be ISO 639-1 valid codes') unless languages_array.select { |x| ISO_639.find(x).nil? }.empty?
   end
 
   ##
@@ -259,7 +261,7 @@ class Program < ApplicationRecord
   def normalize_event_types_length
     event_types.each do |event_type|
       new_length = event_type.length > schedule_interval ? event_type.length - (event_type.length % schedule_interval) : schedule_interval
-      event_type.update_attributes length: new_length
+      event_type.update length: new_length
     end
   end
 end
diff --git a/app/models/qanswer.rb b/app/models/qanswer.rb
index 2e581131..535da321 100644
--- a/app/models/qanswer.rb
+++ b/app/models/qanswer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Qanswer < ApplicationRecord
   belongs_to :question
   belongs_to :answer, dependent: :delete
diff --git a/app/models/question.rb b/app/models/question.rb
index 0c7456a9..702a3784 100644
--- a/app/models/question.rb
+++ b/app/models/question.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Question < ApplicationRecord
   belongs_to :question_type
   has_and_belongs_to_many :conferences
diff --git a/app/models/question_type.rb b/app/models/question_type.rb
index 84fd1a80..2a5ebc24 100644
--- a/app/models/question_type.rb
+++ b/app/models/question_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class QuestionType < ApplicationRecord
   has_many :questions
 end
diff --git a/app/models/registration.rb b/app/models/registration.rb
index 45d2d55b..1bd6af0b 100644
--- a/app/models/registration.rb
+++ b/app/models/registration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Registration < ApplicationRecord
   require 'csv'
   belongs_to :user
@@ -9,7 +11,7 @@ class Registration < ApplicationRecord
   has_many :events_registrations
   has_many :events, through: :events_registrations, dependent: :destroy
 
-  has_paper_trail ignore: %i(updated_at week), meta: { conference_id: :conference_id }
+  has_paper_trail ignore: %i[updated_at week], meta: { conference_id: :conference_id }
 
   accepts_nested_attributes_for :user
   accepts_nested_attributes_for :qanswers
@@ -64,9 +66,7 @@ class Registration < ApplicationRecord
   end
 
   def send_registration_mail
-    if conference.email_settings.send_on_registration?
-      Mailbot.registration_mail(conference, user).deliver_later
-    end
+    Mailbot.registration_mail(conference, user).deliver_later if conference.email_settings.send_on_registration?
   end
 
   def set_week
@@ -77,8 +77,6 @@ class Registration < ApplicationRecord
   end
 
   def registration_limit_not_exceed
-    if conference.registration_limit > 0 && conference.registrations(:reload).count >= conference.registration_limit
-      errors.add(:base, 'Registration limit exceeded')
-    end
+    errors.add(:base, 'Registration limit exceeded') if conference.registration_limit > 0 && conference.registrations(:reload).count >= conference.registration_limit
   end
 end
diff --git a/app/models/registration_period.rb b/app/models/registration_period.rb
index 9aa82444..d5335591 100644
--- a/app/models/registration_period.rb
+++ b/app/models/registration_period.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RegistrationPeriod < ApplicationRecord
   belongs_to :conference
 
@@ -10,15 +12,21 @@ class RegistrationPeriod < ApplicationRecord
   private
 
   def before_end_of_conference
-    errors
-    .add(:start_date, "can't be after the conference end date (#{conference.end_date})") if conference && conference.end_date && start_date && (start_date > conference.end_date)
+    if conference&.end_date && start_date && (start_date > conference.end_date)
+      errors
+        .add(:start_date, "can't be after the conference end date (#{conference.end_date})")
+    end
 
-    errors
-    .add(:end_date, "can't be after the conference end date (#{conference.end_date})") if conference && conference.end_date && end_date && (end_date > conference.end_date)
+    if conference&.end_date && end_date && (end_date > conference.end_date)
+      errors
+        .add(:end_date, "can't be after the conference end date (#{conference.end_date})")
+    end
   end
 
   def start_date_before_end_date
-    errors
-    .add(:start_date, "can't be after the end date") if start_date && end_date && start_date > end_date
+    if start_date && end_date && start_date > end_date
+      errors
+        .add(:start_date, "can't be after the end date")
+    end
   end
 end
diff --git a/app/models/resource.rb b/app/models/resource.rb
index 77363cfb..991ce0cf 100644
--- a/app/models/resource.rb
+++ b/app/models/resource.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Resource < ApplicationRecord
   belongs_to :conference
   validates :name, :used, :quantity, presence: true
diff --git a/app/models/role.rb b/app/models/role.rb
index fcbac932..dd3ff2a6 100644
--- a/app/models/role.rb
+++ b/app/models/role.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class Role < ApplicationRecord
   belongs_to :resource, polymorphic: true
   has_many :users_roles
   has_many :users, through: :users_roles
 
-  has_paper_trail on: [:create, :update], only: [:name, :description], meta: { conference_id: :resource_id }
+  has_paper_trail on: %i[create update], only: %i[name description], meta: { conference_id: :resource_id }
 
   before_destroy :cancel
   scopify
diff --git a/app/models/room.rb b/app/models/room.rb
index 718704de..e80887c8 100644
--- a/app/models/room.rb
+++ b/app/models/room.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Room < ApplicationRecord
   include RevisionCount
   belongs_to :venue
@@ -12,9 +14,7 @@ class Room < ApplicationRecord
 
   validates :size, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
 
-  def conference
-    venue.conference
-  end
+  delegate :conference, to: :venue
 
   private
 
diff --git a/app/models/schedule.rb b/app/models/schedule.rb
index 3bd1f1fa..1584733f 100644
--- a/app/models/schedule.rb
+++ b/app/models/schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Schedule < ApplicationRecord
   belongs_to :program
   belongs_to :track
diff --git a/app/models/splashpage.rb b/app/models/splashpage.rb
index 388831ba..5cd9ef0d 100644
--- a/app/models/splashpage.rb
+++ b/app/models/splashpage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Splashpage < ApplicationRecord
   belongs_to :conference
 
diff --git a/app/models/sponsor.rb b/app/models/sponsor.rb
index d54d95c7..fa63411f 100644
--- a/app/models/sponsor.rb
+++ b/app/models/sponsor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Sponsor < ApplicationRecord
   belongs_to :sponsorship_level
   belongs_to :conference
diff --git a/app/models/sponsorship_level.rb b/app/models/sponsorship_level.rb
index f742e41b..48f41594 100644
--- a/app/models/sponsorship_level.rb
+++ b/app/models/sponsorship_level.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SponsorshipLevel < ApplicationRecord
   validates :title, presence: true
   belongs_to :conference
diff --git a/app/models/subscription.rb b/app/models/subscription.rb
index 9d78975a..3d341bc7 100644
--- a/app/models/subscription.rb
+++ b/app/models/subscription.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 class Subscription < ApplicationRecord
   belongs_to :conference
   belongs_to :user
 
-  has_paper_trail on: %i(create destroy), ignore: [:updated_at], meta: { conference_id: :conference_id }
+  has_paper_trail on: %i[create destroy], ignore: [:updated_at], meta: { conference_id: :conference_id }
 
   validates :user_id, uniqueness: { scope: :conference_id, message: 'already subscribed!' }
 end
diff --git a/app/models/target.rb b/app/models/target.rb
index 55365a6a..424d075f 100644
--- a/app/models/target.rb
+++ b/app/models/target.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Target < ApplicationRecord
   include ActionView::Helpers::TextHelper
 
diff --git a/app/models/ticket.rb b/app/models/ticket.rb
index fa053e0d..a57c90cc 100644
--- a/app/models/ticket.rb
+++ b/app/models/ticket.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Ticket < ApplicationRecord
   belongs_to :conference
   has_many :ticket_purchases, dependent: :destroy
@@ -58,7 +60,7 @@ class Ticket < ApplicationRecord
 
   def self.total_price_user(conference, user, paid: false)
     tickets = TicketPurchase.where(conference: conference, user: user, paid: paid)
-    tickets.inject(0){ |sum, ticket| sum + (ticket.amount_paid * ticket.quantity) }
+    tickets.inject(0) { |sum, ticket| sum + (ticket.amount_paid * ticket.quantity) }
   end
 
   def tickets_turnover_total(id)
@@ -77,8 +79,6 @@ class Ticket < ApplicationRecord
   def tickets_of_conference_have_same_currency
     tickets = Ticket.where(conference_id: conference_id)
     return if tickets.count.zero? || (tickets.count == 1 && self == tickets.first)
-    unless tickets.all?{|t| t.price_currency == price_currency }
-      errors.add(:price_currency, 'is different from the existing tickets of this conference.')
-    end
+    errors.add(:price_currency, 'is different from the existing tickets of this conference.') unless tickets.all? { |t| t.price_currency == price_currency }
   end
 end
diff --git a/app/models/ticket_purchase.rb b/app/models/ticket_purchase.rb
index 35f36b4c..752dbf2b 100644
--- a/app/models/ticket_purchase.rb
+++ b/app/models/ticket_purchase.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TicketPurchase < ApplicationRecord
   belongs_to :ticket
   belongs_to :user
@@ -38,9 +40,7 @@ class TicketPurchase < ApplicationRecord
                      else
                        purchase_ticket(conference, quantity, ticket, user)
                      end
-          if purchase && !purchase.save
-            errors.push(purchase.errors.full_messages)
-          end
+          errors.push(purchase.errors.full_messages) if purchase && !purchase.save
         end
       end
     end
@@ -75,7 +75,7 @@ class TicketPurchase < ApplicationRecord
   end
 
   def pay(payment)
-    update_attributes(paid: true, payment: payment)
+    update(paid: true, payment: payment)
     PhysicalTicket.transaction do
       quantity.times { physical_tickets.create }
     end
@@ -83,15 +83,11 @@ class TicketPurchase < ApplicationRecord
   end
 
   def one_registration_ticket_per_user
-    if ticket.try(:registration_ticket?) && quantity != 1
-      errors.add(:quantity, 'cannot be greater than one for registration tickets.')
-    end
+    errors.add(:quantity, 'cannot be greater than one for registration tickets.') if ticket.try(:registration_ticket?) && quantity != 1
   end
 
   def registration_ticket_already_purchased
-    if ticket.try(:registration_ticket?) && user.tickets.for_registration(conference).present?
-      errors.add(:quantity, 'cannot be greater than one for registration tickets.')
-    end
+    errors.add(:quantity, 'cannot be greater than one for registration tickets.') if ticket.try(:registration_ticket?) && user.tickets.for_registration(conference).present?
   end
 end
 
diff --git a/app/models/ticket_scanning.rb b/app/models/ticket_scanning.rb
index 27536c86..70b9af2f 100644
--- a/app/models/ticket_scanning.rb
+++ b/app/models/ticket_scanning.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TicketScanning < ApplicationRecord
   belongs_to :physical_ticket
 
@@ -6,8 +8,6 @@ class TicketScanning < ApplicationRecord
   private
 
   def mark_user_present
-    if physical_ticket.ticket.registration_ticket?
-      physical_ticket.user.mark_attendance_for_conference(physical_ticket.conference)
-    end
+    physical_ticket.user.mark_attendance_for_conference(physical_ticket.conference) if physical_ticket.ticket.registration_ticket?
   end
 end
diff --git a/app/models/track.rb b/app/models/track.rb
index 21f6eaa1..36cfdab2 100644
--- a/app/models/track.rb
+++ b/app/models/track.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Track < ApplicationRecord
   include ActiveRecord::Transitions
   include RevisionCount
@@ -24,7 +26,7 @@ class Track < ApplicationRecord
             }
   validates :state,
             presence: true,
-            inclusion: { in: %w(new to_accept accepted confirmed to_reject rejected canceled withdrawn) }
+            inclusion: { in: %w[new to_accept accepted confirmed to_reject rejected canceled withdrawn] }
   validates :cfp_active, inclusion: { in: [true, false] }
   validates :start_date, presence: true, if: :self_organized_and_accepted_or_confirmed?
   validates :end_date, presence: true, if: :self_organized_and_accepted_or_confirmed?
@@ -54,34 +56,32 @@ class Track < ApplicationRecord
     state :withdrawn
 
     event :restart do
-      transitions to: :new, from: [:rejected, :withdrawn, :canceled]
+      transitions to: :new, from: %i[rejected withdrawn canceled]
     end
     event :to_accept do
-      transitions to: :to_accept, from: [:new, :to_reject]
+      transitions to: :to_accept, from: %i[new to_reject]
     end
     event :accept do
-      transitions to: :accepted, from: [:new, :to_accept], on_transition: :create_organizer_role
+      transitions to: :accepted, from: %i[new to_accept], on_transition: :create_organizer_role
     end
     event :confirm do
       transitions to: :confirmed, from: [:accepted], on_transition: :assign_role_to_submitter
     end
     event :to_reject do
-      transitions to: :to_reject, from: [:new, :to_accept]
+      transitions to: :to_reject, from: %i[new to_accept]
     end
     event :reject do
-      transitions to: :rejected, from: [:new, :to_reject]
+      transitions to: :rejected, from: %i[new to_reject]
     end
     event :cancel do
-      transitions to: :canceled, from: [:to_accept, :to_reject, :accepted, :confirmed], on_transition: :revoke_role_and_cleanup
+      transitions to: :canceled, from: %i[to_accept to_reject accepted confirmed], on_transition: :revoke_role_and_cleanup
     end
     event :withdraw do
-      transitions to: :withdrawn, from: [:new, :to_accept, :to_reject, :accepted, :confirmed], on_transition: :revoke_role_and_cleanup
+      transitions to: :withdrawn, from: %i[new to_accept to_reject accepted confirmed], on_transition: :revoke_role_and_cleanup
     end
   end
 
-  def conference
-    program.conference
-  end
+  delegate :conference, to: :program
 
   ##
   # Checks if the track is self-organized
@@ -113,10 +113,8 @@ class Track < ApplicationRecord
   def revoke_role_and_cleanup
     role = Role.find_by(name: 'track_organizer', resource: self)
 
-    if role
-      role.users.each do |user|
-        user.remove_role 'track_organizer', self
-      end
+    role&.users&.each do |user|
+      user.remove_role 'track_organizer', self
     end
 
     self.selected_schedule_id = nil
@@ -175,9 +173,9 @@ class Track < ApplicationRecord
 
   def generate_guid
     guid = SecureRandom.urlsafe_base64
-#     begin
-#       guid = SecureRandom.urlsafe_base64
-#     end while Person.where(:guid => guid).exists?
+    #     begin
+    #       guid = SecureRandom.urlsafe_base64
+    #     end while Person.where(:guid => guid).exists?
     self.guid = guid
   end
 
@@ -227,12 +225,11 @@ class Track < ApplicationRecord
     return unless start_date && end_date && room && program.try(:tracks)
     (program.tracks.accepted + program.tracks.confirmed - [self]).each do |existing_track|
       next unless existing_track.room == room && existing_track.start_date && existing_track.end_date
-      if start_date >= existing_track.start_date && start_date <= existing_track.end_date ||
-         end_date >= existing_track.start_date && end_date <= existing_track.end_date ||
-         start_date <= existing_track.start_date && end_date >= existing_track.end_date
-        errors.add(:track, 'has overlapping dates with a confirmed or accepted track in the same room')
-        break
-      end
+      next unless start_date >= existing_track.start_date && start_date <= existing_track.end_date ||
+                  end_date >= existing_track.start_date && end_date <= existing_track.end_date ||
+                  start_date <= existing_track.start_date && end_date >= existing_track.end_date
+      errors.add(:track, 'has overlapping dates with a confirmed or accepted track in the same room')
+      break
     end
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index cb09e78c..cdd3e241 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IChainRecordNotFound < StandardError
 end
 
@@ -17,8 +19,8 @@ class User < ApplicationRecord
   has_many :users_roles
   has_many :roles, through: :users_roles, dependent: :destroy
 
-  has_paper_trail on: [:create, :update], ignore: [:sign_in_count, :remember_created_at, :current_sign_in_at, :last_sign_in_at, :current_sign_in_ip, :last_sign_in_ip, :unconfirmed_email,
-                                                   :avatar_content_type, :avatar_file_size, :avatar_updated_at, :updated_at, :confirmation_sent_at, :confirmation_token, :reset_password_token]
+  has_paper_trail on: %i[create update], ignore: %i[sign_in_countremember_created_atcurrent_sign_in_atlast_sign_in_atcurrent_sign_in_iplast_sign_in_ipunconfirmed_email
+                                                    avatar_content_type avatar_file_size avatar_updated_at updated_at confirmation_sent_at confirmation_token reset_password_token]
 
   include Gravtastic
   gravtastic size: 32
@@ -28,7 +30,7 @@ class User < ApplicationRecord
   after_save :touch_events
 
   # add scope
-  scope :comment_notifiable, ->(conference) {joins(:roles).where('roles.name IN (?)', [:organizer, :cfp]).where('roles.resource_type = ? AND roles.resource_id = ?', 'Conference', conference.id)}
+  scope :comment_notifiable, ->(conference) { joins(:roles).where('roles.name IN (?)', %i[organizer cfp]).where('roles.resource_type = ? AND roles.resource_id = ?', 'Conference', conference.id) }
 
   # Include default devise modules. Others available are:
   # :token_authenticatable, :confirmable,
@@ -40,7 +42,7 @@ class User < ApplicationRecord
                     else
                       [:database_authenticatable, :registerable,
                        :recoverable, :rememberable, :trackable, :validatable, :confirmable,
-                       :omniauthable, omniauth_providers: [:suse, :google, :facebook, :github]]
+                       :omniauthable, omniauth_providers: %i[suse google facebook github]]
                     end
 
   devise(*devise_modules)
@@ -51,9 +53,9 @@ class User < ApplicationRecord
 
   has_many :event_users, dependent: :destroy
   has_many :events, -> { distinct }, through: :event_users
-  has_many :presented_events, -> { joins(:event_users).where(event_users: {event_role: 'speaker'}).distinct }, through: :event_users, source: :event
+  has_many :presented_events, -> { joins(:event_users).where(event_users: { event_role: 'speaker' }).distinct }, through: :event_users, source: :event
   has_many :registrations, dependent: :destroy do
-    def for_conference conference
+    def for_conference(conference)
       where(conference: conference).first
     end
   end
@@ -61,7 +63,7 @@ class User < ApplicationRecord
   has_many :ticket_purchases, dependent: :destroy
   has_many :payments, dependent: :destroy
   has_many :tickets, through: :ticket_purchases, source: :ticket do
-    def for_registration conference
+    def for_registration(conference)
       where(conference: conference, registration_ticket: true).first
     end
   end
@@ -81,7 +83,7 @@ class User < ApplicationRecord
 
   validates :username,
             uniqueness: {
-                case_sensitive: false
+              case_sensitive: false
             },
             presence: true
 
@@ -95,48 +97,48 @@ class User < ApplicationRecord
   # === Returns
   # * +true+ if the user attended the event
   # * +false+ if the user did not attend the event
-  def attended_event? event
+  def attended_event?(event)
     event_registration = event.events_registrations.find_by(registration: registrations)
 
-    return false unless event_registration.present?
+    return false if event_registration.blank?
     event_registration.attended
   end
 
-  def mark_attendance_for_conference conference
+  def mark_attendance_for_conference(conference)
     registration = registrations.for_conference(conference)
     registration.attended = true
     registration.save
   end
 
   def name
-    self[:name].blank? ? username : self[:name]
+    self[:name].presence || username
   end
 
   ##
   # Checks if a user has registered to an event
   # ====Returns
   # * +true+ or +false+
-  def registered_to_event? event
+  def registered_to_event?(event)
     event.registrations.include? registrations.find_by(conference: event.program.conference)
   end
 
-  def subscribed? conference
+  def subscribed?(conference)
     subscriptions.find_by(conference_id: conference.id).present?
   end
 
-  def supports? conference
+  def supports?(conference)
     ticket_purchases.find_by(conference_id: conference.id).present?
   end
 
   def self.for_ichain_username(username, attributes)
     user = find_by(username: username)
 
-    raise UserDisabled if user && user.is_disabled
+    raise UserDisabled if user&.is_disabled
 
     if user
-      user.update_attributes(email: attributes[:email],
-                             last_sign_in_at: user.current_sign_in_at,
-                             current_sign_in_at: Time.current)
+      user.update(email: attributes[:email],
+                  last_sign_in_at: user.current_sign_in_at,
+                  current_sign_in_at: Time.current)
     else
       begin
         user = create!(username: username, email: attributes[:email])
@@ -163,9 +165,7 @@ class User < ApplicationRecord
   def self.find_for_auth(auth, current_user = nil)
     user = current_user
 
-    if user.nil? # No current user available, user is not already logged in
-      user = User.where(email: auth.info.email).first_or_initialize
-    end
+    user = User.where(email: auth.info.email).first_or_initialize if user.nil? # No current user available, user is not already logged in
 
     if user.new_record?
       user.email = auth.info.email
@@ -231,9 +231,7 @@ class User < ApplicationRecord
   private
 
   def setup_role
-    if User.count == 1 && User.first.email == 'deleted@localhost.osem'
-      self.is_admin = true
-    end
+    self.is_admin = true if User.count == 1 && User.first.email == 'deleted@localhost.osem'
   end
 
   def touch_events
diff --git a/app/models/users_role.rb b/app/models/users_role.rb
index f233e995..6e8d86fb 100644
--- a/app/models/users_role.rb
+++ b/app/models/users_role.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 class UsersRole < ApplicationRecord
   belongs_to :role
   belongs_to :user
 
-  has_paper_trail on: [:create, :destroy], meta: { conference_id: :conference_id }
+  has_paper_trail on: %i[create destroy], meta: { conference_id: :conference_id }
 
   private
 
diff --git a/app/models/vchoice.rb b/app/models/vchoice.rb
index b258c34d..bf5d05a6 100644
--- a/app/models/vchoice.rb
+++ b/app/models/vchoice.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vchoice < ApplicationRecord
   belongs_to :vday
   belongs_to :vposition
diff --git a/app/models/vday.rb b/app/models/vday.rb
index bd122291..5a9b52cf 100644
--- a/app/models/vday.rb
+++ b/app/models/vday.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vday < ApplicationRecord
   belongs_to :conference
 
diff --git a/app/models/venue.rb b/app/models/venue.rb
index 6a758242..7139c042 100644
--- a/app/models/venue.rb
+++ b/app/models/venue.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 class Venue < ApplicationRecord
   belongs_to :conference
   has_one :commercial, as: :commercialable, dependent: :destroy
   has_many :rooms, dependent: :destroy
   before_create :generate_guid
 
-  has_paper_trail ignore: [:updated_at, :guid], meta: { conference_id: :conference_id }
+  has_paper_trail ignore: %i[updated_at guid], meta: { conference_id: :conference_id }
 
   accepts_nested_attributes_for :commercial, allow_destroy: true
   validates :name, :street, :city, :country, presence: true
@@ -19,7 +21,7 @@ class Venue < ApplicationRecord
 
   def country_name
     name = ISO3166::Country[country]
-    name.name if name
+    name&.name
   end
 
   def location?
@@ -37,7 +39,7 @@ class Venue < ApplicationRecord
     # do not notify unless the address changed
     return false unless name_changed? || street_changed? || city_changed? || country_changed?
     # do not notify unless the mail content is set up
-    (!conference.email_settings.venue_updated_subject.blank? && !conference.email_settings.venue_updated_body.blank?)
+    (conference.email_settings.venue_updated_subject.present? && conference.email_settings.venue_updated_body.present?)
   end
 
   # TODO: create a module to be mixed into model to perform same operation
diff --git a/app/models/visit.rb b/app/models/visit.rb
index 76b1981b..0afa9183 100644
--- a/app/models/visit.rb
+++ b/app/models/visit.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Visit < ApplicationRecord
   has_many :ahoy_events, class_name: 'Ahoy::Event'
   belongs_to :user
diff --git a/app/models/vote.rb b/app/models/vote.rb
index 9e1c572f..2ce0e671 100644
--- a/app/models/vote.rb
+++ b/app/models/vote.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vote < ApplicationRecord
   belongs_to :user
   belongs_to :event
diff --git a/app/models/vposition.rb b/app/models/vposition.rb
index 38ef27fe..6599bc8a 100644
--- a/app/models/vposition.rb
+++ b/app/models/vposition.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Vposition < ApplicationRecord
   belongs_to :conference
 
diff --git a/app/pdfs/ticket_pdf.rb b/app/pdfs/ticket_pdf.rb
index d21a1e27..834d12e2 100644
--- a/app/pdfs/ticket_pdf.rb
+++ b/app/pdfs/ticket_pdf.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'open-uri'
 
 class TicketPdf < Prawn::Document
diff --git a/app/serializers/conference_serializer.rb b/app/serializers/conference_serializer.rb
index 7bb96131..fa94ad78 100644
--- a/app/serializers/conference_serializer.rb
+++ b/app/serializers/conference_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ConferenceSerializer < ActiveModel::Serializer
   include ApplicationHelper
   attributes :short_title, :title, :description, :start_date, :end_date, :picture_url,
@@ -5,41 +7,41 @@ class ConferenceSerializer < ActiveModel::Serializer
              :date_range, :revision
 
   def difficulty_levels
-    object.program.difficulty_levels.map do |difficulty_level| { id: difficulty_level.id,
-                                                                 title: difficulty_level.title,
-                                                                 description: difficulty_level.description
-                                                               }
+    object.program.difficulty_levels.map do |difficulty_level|
+      { id: difficulty_level.id,
+        title: difficulty_level.title,
+        description: difficulty_level.description }
     end
   end
 
   def event_types
-    object.program.event_types.map do |event_type| { id: event_type.id,
-                                                     title: event_type.title,
-                                                     length: event_type.length,
-                                                     description: event_type.description
-                                                   }
+    object.program.event_types.map do |event_type|
+      { id: event_type.id,
+        title: event_type.title,
+        length: event_type.length,
+        description: event_type.description }
     end
   end
 
   def rooms
     if object.venue
-      object.venue.rooms.map do |room| { id: room.id,
-                                         size: room.size,
-                                         events: room.event_schedules.map do |event_schedule| { guid: event_schedule.event.title,
-                                                                                                title:  event_schedule.event.title,
-                                                                                                subtitle: event_schedule.event.subtitle,
-                                                                                                abstract: event_schedule.event.abstract,
-                                                                                                description: event_schedule.event.description,
-                                                                                                is_highlight: event_schedule.event.is_highlight,
-                                                                                                require_registration:  event_schedule.event.require_registration,
-                                                                                                start_time: event_schedule.start_time,
-                                                                                                event_type_id: event_schedule.event.event_type.id,
-                                                                                                difficulty_level_id: event_schedule.event.difficulty_level_id,
-                                                                                                track_id: event_schedule.event.track_id,
-                                                                                                speaker_names: event_schedule.event.speaker_names
-                                                                                              }
-                                                 end
-                                       }
+      object.venue.rooms.map do |room|
+        { id: room.id,
+          size: room.size,
+          events: room.event_schedules.map do |event_schedule|
+                    { guid: event_schedule.event.title,
+                      title:  event_schedule.event.title,
+                      subtitle: event_schedule.event.subtitle,
+                      abstract: event_schedule.event.abstract,
+                      description: event_schedule.event.description,
+                      is_highlight: event_schedule.event.is_highlight,
+                      require_registration:  event_schedule.event.require_registration,
+                      start_time: event_schedule.start_time,
+                      event_type_id: event_schedule.event.event_type.id,
+                      difficulty_level_id: event_schedule.event.difficulty_level_id,
+                      track_id: event_schedule.event.track_id,
+                      speaker_names: event_schedule.event.speaker_names }
+                  end }
       end
     else
       []
@@ -47,10 +49,10 @@ class ConferenceSerializer < ActiveModel::Serializer
   end
 
   def tracks
-    object.program.tracks.map do |track| { 'id' => track.id,
-                                           'name' => track.name,
-                                           'description' => track.description
-                                         }
+    object.program.tracks.map do |track|
+      { 'id' => track.id,
+        'name' => track.name,
+        'description' => track.description }
     end
   end
 
@@ -59,8 +61,6 @@ class ConferenceSerializer < ActiveModel::Serializer
   end
 
   def date_range
-    if defined? date_string(object.start_date, object.end_date)
-      date_string(object.start_date, object.end_date).try(:split, ',').try(:first)
-    end
+    date_string(object.start_date, object.end_date).try(:split, ',').try(:first) if defined? date_string(object.start_date, object.end_date)
   end
 end
diff --git a/app/serializers/conferences_array_serializer.rb b/app/serializers/conferences_array_serializer.rb
index aacaa681..8ca8df53 100644
--- a/app/serializers/conferences_array_serializer.rb
+++ b/app/serializers/conferences_array_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #
 # Needed in order to add the API version number to the conferences array
 #
diff --git a/app/serializers/event_schedule_serializer.rb b/app/serializers/event_schedule_serializer.rb
index c0de52eb..71a2ea59 100644
--- a/app/serializers/event_schedule_serializer.rb
+++ b/app/serializers/event_schedule_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventScheduleSerializer < ActiveModel::Serializer
   include ActionView::Helpers::TextHelper
 
diff --git a/app/serializers/event_serializer.rb b/app/serializers/event_serializer.rb
index d58d23d2..26d53801 100644
--- a/app/serializers/event_serializer.rb
+++ b/app/serializers/event_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EventSerializer < ActiveModel::Serializer
   include ActionView::Helpers::TextHelper
 
diff --git a/app/serializers/room_serializer.rb b/app/serializers/room_serializer.rb
index fc9b1921..c75db316 100644
--- a/app/serializers/room_serializer.rb
+++ b/app/serializers/room_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RoomSerializer < ActiveModel::Serializer
   attributes :guid, :name, :description
 
diff --git a/app/serializers/speaker_serializer.rb b/app/serializers/speaker_serializer.rb
index 4a455a61..ee7e6dec 100644
--- a/app/serializers/speaker_serializer.rb
+++ b/app/serializers/speaker_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SpeakerSerializer < ActiveModel::Serializer
   include ActionView::Helpers::TextHelper
 
diff --git a/app/serializers/track_serializer.rb b/app/serializers/track_serializer.rb
index 0019a150..0eb7bebb 100644
--- a/app/serializers/track_serializer.rb
+++ b/app/serializers/track_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TrackSerializer < ActiveModel::Serializer
   attributes :guid, :name, :color
 end
diff --git a/app/uploaders/picture_uploader.rb b/app/uploaders/picture_uploader.rb
index 41bcab7b..7fbaadf7 100644
--- a/app/uploaders/picture_uploader.rb
+++ b/app/uploaders/picture_uploader.rb
@@ -1,4 +1,4 @@
-# encoding: utf-8
+# frozen_string_literal: true
 
 class PictureUploader < CarrierWave::Uploader::Base
   include CarrierWave::MiniMagick
@@ -43,7 +43,7 @@ class PictureUploader < CarrierWave::Uploader::Base
   # Returns the id of the instance in a split path form. e.g. returns
   # 000/001/234 for an id of 1234. Stolen from paperclip...
   def id_partition
-    ('%09d'.freeze % model.id).scan(/\d{3}/).join('/'.freeze)
+    format('%09d', model.id).scan(/\d{3}/).join('/')
   end
 
   # Override the directory where uploaded files will be stored.
@@ -84,7 +84,7 @@ class PictureUploader < CarrierWave::Uploader::Base
   # Add a white list of extensions which are allowed to be uploaded.
   # For images you might use something like this:
   def extension_white_list
-    %w(jpg jpeg gif png)
+    %w[jpg jpeg gif png]
   end
 
   def content_type_whitelist
diff --git a/app/views/admin/booths/_all_booths.xlsx.axlsx b/app/views/admin/booths/_all_booths.xlsx.axlsx
index bd1cc1db..81d1ce0d 100644
--- a/app/views/admin/booths/_all_booths.xlsx.axlsx
+++ b/app/views/admin/booths/_all_booths.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'all booths') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Booth ID',
          'Title',
          'Description',
@@ -21,7 +23,7 @@ wb.add_worksheet(name: 'all booths') do |sheet|
     row << booth.submitter_relationship
     row << booth.website_url
     row << booth.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,20,35,35,20,30,35,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 20, 35, 35, 20, 30, 35, 10
   end
 end
diff --git a/app/views/admin/booths/_confirmed_booths.xlsx.axlsx b/app/views/admin/booths/_confirmed_booths.xlsx.axlsx
index 2dc10013..8c990f77 100644
--- a/app/views/admin/booths/_confirmed_booths.xlsx.axlsx
+++ b/app/views/admin/booths/_confirmed_booths.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'all booths') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Booth ID',
          'Title',
          'Description',
@@ -21,7 +23,7 @@ wb.add_worksheet(name: 'all booths') do |sheet|
     row << booth.submitter_relationship
     row << booth.website_url
     row << booth.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,20,35,35,20,30,35,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 20, 35, 35, 20, 30, 35, 10
   end
 end
diff --git a/app/views/admin/booths/booths.xlsx.axlsx b/app/views/admin/booths/booths.xlsx.axlsx
index 5fe084db..33d16e72 100644
--- a/app/views/admin/booths/booths.xlsx.axlsx
+++ b/app/views/admin/booths/booths.xlsx.axlsx
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 xlsx_package.use_autowidth = true
 if @booth_export_option == 'confirmed'
diff --git a/app/views/admin/events/_all_events.xlsx.axlsx b/app/views/admin/events/_all_events.xlsx.axlsx
index 3197cf38..44f4deb6 100644
--- a/app/views/admin/events/_all_events.xlsx.axlsx
+++ b/app/views/admin/events/_all_events.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'all events') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Event ID',
          'Title',
          'Abstract',
@@ -20,7 +22,7 @@ wb.add_worksheet(name: 'all events') do |sheet|
     row << event.id
     row << event.title
     row << event.abstract
-    row << (event.time.present? ? "#{event.time.strftime("%Y-%m-%d")} #{event.time.strftime("%I:%M%p")} " : '')
+    row << (event.time.present? ? "#{event.time.strftime('%Y-%m-%d')} #{event.time.strftime('%I:%M%p')} " : '')
     row << event.submitter.name
     row << event.speaker_names
     row << event.speaker_emails
@@ -29,7 +31,7 @@ wb.add_worksheet(name: 'all events') do |sheet|
     row << (event.difficulty_level.present? ? event.difficulty_level.title : '')
     row << (event.room.present? ? event.room.name : '')
     row << event.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,15,35,13,18,18,28,12,15,15,15,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 15, 35, 13, 18, 18, 28, 12, 15, 15, 15, 10
   end
 end
diff --git a/app/views/admin/events/_all_with_comments.xlsx.axlsx b/app/views/admin/events/_all_with_comments.xlsx.axlsx
index fd798ca5..8a877c79 100644
--- a/app/views/admin/events/_all_with_comments.xlsx.axlsx
+++ b/app/views/admin/events/_all_with_comments.xlsx.axlsx
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 wb.use_shared_strings = true
 wb.add_worksheet(name: 'events with comments') do |sheet|
   bold_style = wb.styles.add_style(b: true)
@@ -20,13 +22,13 @@ wb.add_worksheet(name: 'events with comments') do |sheet|
   @events.each do |event|
     all_comments = ''
     event.root_comments.each do |comment|
-      all_comments <<  "#{comment.created_at.strftime("%Y-%m-%d")} #{comment.created_at.strftime("%I:%M%p")}  #{comment.user.name}: #{comment.body}\n"
+      all_comments << "#{comment.created_at.strftime('%Y-%m-%d')} #{comment.created_at.strftime('%I:%M%p')}  #{comment.user.name}: #{comment.body}\n"
     end
     row = []
     row << event.id
     row << event.title
     row << event.abstract
-    row << (event.time.present? ? "#{event.time.strftime("%Y-%m-%d")} #{event.time.strftime("%I:%M%p")} " : '')
+    row << (event.time.present? ? "#{event.time.strftime('%Y-%m-%d')} #{event.time.strftime('%I:%M%p')} " : '')
     row << event.submitter.name
     row << event.speaker_names
     row << event.speaker_emails
@@ -37,6 +39,6 @@ wb.add_worksheet(name: 'events with comments') do |sheet|
     row << event.state
     row << all_comments.strip
     sheet.add_row row, style: cell_style
-    sheet.column_widths 10,15,35,13,18,18,28,12,15,15,15,10
+    sheet.column_widths 10, 15, 35, 13, 18, 18, 28, 12, 15, 15, 15, 10
   end
 end
diff --git a/app/views/admin/events/_confirmed_events.xlsx.axlsx b/app/views/admin/events/_confirmed_events.xlsx.axlsx
index a1c8c886..204bcb5c 100644
--- a/app/views/admin/events/_confirmed_events.xlsx.axlsx
+++ b/app/views/admin/events/_confirmed_events.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'confirmed events') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Event ID',
          'Title',
          'Abstract',
@@ -20,7 +22,7 @@ wb.add_worksheet(name: 'confirmed events') do |sheet|
     row << event.id
     row << event.title
     row << event.abstract
-    row << (event.time.present? ? "#{event.time.strftime("%Y-%m-%d")} #{event.time.strftime("%I:%M%p")} " : '')
+    row << (event.time.present? ? "#{event.time.strftime('%Y-%m-%d')} #{event.time.strftime('%I:%M%p')} " : '')
     row << event.submitter.name
     row << event.speaker_names
     row << event.speaker_emails
@@ -29,7 +31,7 @@ wb.add_worksheet(name: 'confirmed events') do |sheet|
     row << (event.difficulty_level.present? ? event.difficulty_level.title : '')
     row << (event.room.present? ? event.room.name : '')
     row << event.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,15,35,13,18,18,28,12,15,15,15,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 15, 35, 13, 18, 18, 28, 12, 15, 15, 15, 10
   end
 end
diff --git a/app/views/admin/events/events.xlsx.axlsx b/app/views/admin/events/events.xlsx.axlsx
index abfd1365..bc90bd79 100644
--- a/app/views/admin/events/events.xlsx.axlsx
+++ b/app/views/admin/events/events.xlsx.axlsx
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 if @event_export_option == 'confirmed'
-  render partial: 'confirmed_events', locals: {:wb => wb}
+  render partial: 'confirmed_events', locals: { wb: wb }
 elsif @event_export_option == 'all'
-  render partial: 'all_events', locals: {:wb => wb}
+  render partial: 'all_events', locals: { wb: wb }
 elsif @event_export_option == 'all_with_comments'
-  render partial: 'all_with_comments', locals: {:wb => wb}
+  render partial: 'all_with_comments', locals: { wb: wb }
 end
diff --git a/app/views/admin/registrations/index.xlsx.axlsx b/app/views/admin/registrations/index.xlsx.axlsx
index babc24ef..57fa5bb6 100644
--- a/app/views/admin/registrations/index.xlsx.axlsx
+++ b/app/views/admin/registrations/index.xlsx.axlsx
@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 wb.add_worksheet(name: 'registrations') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  row = ['Attended', 'Name', 'Nickname', 'Affilιation', 'Email', 'Arrival', 'Departure']
+  row = %w[Attended Name Nickname Affilιation Email Arrival Departure]
 
   @conference.questions.each do |question|
     row << question.title
   end
 
-  sheet.add_row row, :style => bold_style
+  sheet.add_row row, style: bold_style
 
   @registrations.each do |registration|
     row = []
-    row << ( registration.attended ? 'X' : '' )
+    row << (registration.attended ? 'X' : '')
     row << registration.name
     row << registration.nickname
     row << registration.affiliation
@@ -20,7 +22,7 @@ wb.add_worksheet(name: 'registrations') do |sheet|
     row << registration.departure.to_s
     @conference.questions.each do |question|
       qa = registration.qanswers.find_by(question: question)
-      answer = ( qa ? qa.answer.title : '' )
+      answer = (qa ? qa.answer.title : '')
 
       row << answer
     end
@@ -28,4 +30,3 @@ wb.add_worksheet(name: 'registrations') do |sheet|
     sheet.add_row row
   end
 end
-
diff --git a/app/views/admin/tracks/_all_tracks.xlsx.axlsx b/app/views/admin/tracks/_all_tracks.xlsx.axlsx
index d1397193..ee29fb33 100644
--- a/app/views/admin/tracks/_all_tracks.xlsx.axlsx
+++ b/app/views/admin/tracks/_all_tracks.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'all tracks') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Track ID',
          'Name',
          'Description',
@@ -23,7 +25,7 @@ wb.add_worksheet(name: 'all tracks') do |sheet|
     row << track.try(:submitter).try(:name)
     row << (track.cfp_active? ? 'Yes' : 'No')
     row << track.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,20,50,20,12,12,20,15,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 20, 50, 20, 12, 12, 20, 15, 10
   end
 end
diff --git a/app/views/admin/tracks/_confirmed_tracks.xlsx.axlsx b/app/views/admin/tracks/_confirmed_tracks.xlsx.axlsx
index 673b985c..6c3c84ee 100644
--- a/app/views/admin/tracks/_confirmed_tracks.xlsx.axlsx
+++ b/app/views/admin/tracks/_confirmed_tracks.xlsx.axlsx
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 wb.add_worksheet(name: 'all tracks') do |sheet|
   bold_style = wb.styles.add_style(b: true)
-  wrap_text = wb.styles.add_style alignment: {wrap_text: true}
+  wrap_text = wb.styles.add_style alignment: { wrap_text: true }
   row = ['Track ID',
          'Name',
          'Description',
@@ -23,7 +25,7 @@ wb.add_worksheet(name: 'all tracks') do |sheet|
     row << track.try(:submitter).try(:name)
     row << (track.cfp_active? ? 'Yes' : 'No')
     row << track.state
-    sheet.add_row row , style: wrap_text
-    sheet.column_widths 10,20,50,20,12,12,20,15,10
+    sheet.add_row row, style: wrap_text
+    sheet.column_widths 10, 20, 50, 20, 12, 12, 20, 15, 10
   end
 end
diff --git a/app/views/admin/tracks/tracks.xlsx.axlsx b/app/views/admin/tracks/tracks.xlsx.axlsx
index 6a84da9b..f90b6005 100644
--- a/app/views/admin/tracks/tracks.xlsx.axlsx
+++ b/app/views/admin/tracks/tracks.xlsx.axlsx
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 wb = xlsx_package.workbook
 if @track_export_option == 'confirmed'
   render partial: 'confirmed_tracks', locals: { wb: wb }
diff --git a/config.ru b/config.ru
index a0123600..ccfab02b 100644
--- a/config.ru
+++ b/config.ru
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
-require ::File.expand_path('../config/environment',  __FILE__)
+require ::File.expand_path('../config/environment', __FILE__)
 use Rack::Deflater
 run Osem::Application
diff --git a/db/migrate/20121223110942_devise_create_users.rb b/db/migrate/20121223110942_devise_create_users.rb
index 60cc97dc..c566b064 100644
--- a/db/migrate/20121223110942_devise_create_users.rb
+++ b/db/migrate/20121223110942_devise_create_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeviseCreateUsers < ActiveRecord::Migration
   def up
     create_table(:users) do |t|
diff --git a/db/migrate/20121223115038_create_conferences_table.rb b/db/migrate/20121223115038_create_conferences_table.rb
index 932b66e7..2f2e170e 100644
--- a/db/migrate/20121223115038_create_conferences_table.rb
+++ b/db/migrate/20121223115038_create_conferences_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateConferencesTable < ActiveRecord::Migration
   def up
     create_table :conferences do |t|
diff --git a/db/migrate/20121223115106_create_people_table.rb b/db/migrate/20121223115106_create_people_table.rb
index 75563b7d..63160bb8 100644
--- a/db/migrate/20121223115106_create_people_table.rb
+++ b/db/migrate/20121223115106_create_people_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreatePeopleTable < ActiveRecord::Migration
   def up
     create_table :people do |t|
diff --git a/db/migrate/20121223115117_create_rooms_table.rb b/db/migrate/20121223115117_create_rooms_table.rb
index 0a45ac62..57cf72e6 100644
--- a/db/migrate/20121223115117_create_rooms_table.rb
+++ b/db/migrate/20121223115117_create_rooms_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateRoomsTable < ActiveRecord::Migration
   def up
     create_table :rooms do |t|
diff --git a/db/migrate/20121223115125_create_tracks_table.rb b/db/migrate/20121223115125_create_tracks_table.rb
index 5680c476..067bdad1 100644
--- a/db/migrate/20121223115125_create_tracks_table.rb
+++ b/db/migrate/20121223115125_create_tracks_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateTracksTable < ActiveRecord::Migration
   def up
     create_table :tracks do |t|
@@ -11,6 +13,5 @@ class CreateTracksTable < ActiveRecord::Migration
     end
   end
 
-  def down
-  end
+  def down; end
 end
diff --git a/db/migrate/20121223115135_create_events_table.rb b/db/migrate/20121223115135_create_events_table.rb
index 56f14f36..6ec49ff0 100644
--- a/db/migrate/20121223115135_create_events_table.rb
+++ b/db/migrate/20121223115135_create_events_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventsTable < ActiveRecord::Migration
   def up
     create_table :events do |t|
@@ -26,6 +28,5 @@ class CreateEventsTable < ActiveRecord::Migration
     end
   end
 
-  def down
-  end
+  def down; end
 end
diff --git a/db/migrate/20121223120413_create_event_types.rb b/db/migrate/20121223120413_create_event_types.rb
index 3257ade4..f34dfa77 100644
--- a/db/migrate/20121223120413_create_event_types.rb
+++ b/db/migrate/20121223120413_create_event_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventTypes < ActiveRecord::Migration
   def up
     create_table :event_types do |t|
diff --git a/db/migrate/20121223122307_create_event_people_table.rb b/db/migrate/20121223122307_create_event_people_table.rb
index 27e32a44..3ac46fa2 100644
--- a/db/migrate/20121223122307_create_event_people_table.rb
+++ b/db/migrate/20121223122307_create_event_people_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventPeopleTable < ActiveRecord::Migration
   def self.up
     create_table :event_people do |t|
diff --git a/db/migrate/20121223122842_create_venue_table.rb b/db/migrate/20121223122842_create_venue_table.rb
index 38e7115f..f2a07e39 100644
--- a/db/migrate/20121223122842_create_venue_table.rb
+++ b/db/migrate/20121223122842_create_venue_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVenueTable < ActiveRecord::Migration
   def up
     create_table :venues do |t|
diff --git a/db/migrate/20121223135240_create_roles_table.rb b/db/migrate/20121223135240_create_roles_table.rb
index 2fa3e899..fc3b5119 100644
--- a/db/migrate/20121223135240_create_roles_table.rb
+++ b/db/migrate/20121223135240_create_roles_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateRolesTable < ActiveRecord::Migration
   def self.up
     create_table :roles do |t|
diff --git a/db/migrate/20121223135447_user_roles_table.rb b/db/migrate/20121223135447_user_roles_table.rb
index 459b3172..70aec74c 100644
--- a/db/migrate/20121223135447_user_roles_table.rb
+++ b/db/migrate/20121223135447_user_roles_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UserRolesTable < ActiveRecord::Migration
   def self.up
     create_table :roles_users, id: false do |t|
diff --git a/db/migrate/20121224144728_create_cfp_table.rb b/db/migrate/20121224144728_create_cfp_table.rb
index eb730271..03ef90dc 100644
--- a/db/migrate/20121224144728_create_cfp_table.rb
+++ b/db/migrate/20121224144728_create_cfp_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateCfpTable < ActiveRecord::Migration
   def up
     create_table :call_for_papers do |t|
diff --git a/db/migrate/20130103134212_create_registrations_table.rb b/db/migrate/20130103134212_create_registrations_table.rb
index 41877ad5..c9b604d8 100644
--- a/db/migrate/20130103134212_create_registrations_table.rb
+++ b/db/migrate/20130103134212_create_registrations_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateRegistrationsTable < ActiveRecord::Migration
   def up
     create_table :registrations do |t|
@@ -14,6 +16,5 @@ class CreateRegistrationsTable < ActiveRecord::Migration
     end
   end
 
-  def down
-  end
+  def down; end
 end
diff --git a/db/migrate/20130104142209_create_comments.rb b/db/migrate/20130104142209_create_comments.rb
index b9c9ce79..3e49125a 100644
--- a/db/migrate/20130104142209_create_comments.rb
+++ b/db/migrate/20130104142209_create_comments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateComments < ActiveRecord::Migration
   def self.up
     create_table :comments do |t|
diff --git a/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb b/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
index d70bee0f..ff53ee5c 100644
--- a/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
+++ b/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ActsAsCommentableUpgradeMigration < ActiveRecord::Migration
   def self.up
     rename_column :comments, :comment, :body
diff --git a/db/migrate/20130105115603_create_event_attachments_table.rb b/db/migrate/20130105115603_create_event_attachments_table.rb
index 0332eb03..9de9fd2d 100644
--- a/db/migrate/20130105115603_create_event_attachments_table.rb
+++ b/db/migrate/20130105115603_create_event_attachments_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventAttachmentsTable < ActiveRecord::Migration
   def up
     create_table :event_attachments do |t|
diff --git a/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb b/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
index 912c639b..5aff90b2 100644
--- a/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
+++ b/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRegistrationDatesToConferencesTable < ActiveRecord::Migration
   def change
     add_column :conferences, :registration_start_date, :date
diff --git a/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb b/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
index 5eaa39df..78c126b2 100644
--- a/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
+++ b/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveCfpAndRegBooleansFromConferences < ActiveRecord::Migration
   def up
     remove_column :conferences, :cfp_open
diff --git a/db/migrate/20130107114930_create_versions.rb b/db/migrate/20130107114930_create_versions.rb
index 02694362..91d11caf 100644
--- a/db/migrate/20130107114930_create_versions.rb
+++ b/db/migrate/20130107114930_create_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVersions < ActiveRecord::Migration
   def self.up
     create_table :versions do |t|
@@ -9,11 +11,11 @@ class CreateVersions < ActiveRecord::Migration
       t.text     :object_changes
       t.datetime :created_at
     end
-    add_index :versions, [:item_type, :item_id]
+    add_index :versions, %i[item_type item_id]
   end
 
   def self.down
-    remove_index :versions, [:item_type, :item_id]
+    remove_index :versions, %i[item_type item_id]
     drop_table :versions
   end
 end
diff --git a/db/migrate/20130113105652_create_email_table.rb b/db/migrate/20130113105652_create_email_table.rb
index a7b6b3e6..8a38dfd4 100644
--- a/db/migrate/20130113105652_create_email_table.rb
+++ b/db/migrate/20130113105652_create_email_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEmailTable < ActiveRecord::Migration
   def up
     create_table :email_settings do |t|
diff --git a/db/migrate/20130113132225_add_subjects_to_email_settings.rb b/db/migrate/20130113132225_add_subjects_to_email_settings.rb
index 9adb821c..8242c1fb 100644
--- a/db/migrate/20130113132225_add_subjects_to_email_settings.rb
+++ b/db/migrate/20130113132225_add_subjects_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSubjectsToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :registration_subject, :string
diff --git a/db/migrate/20130117130949_add_logo_to_conferences_table.rb b/db/migrate/20130117130949_add_logo_to_conferences_table.rb
index 454c33c9..47197b08 100644
--- a/db/migrate/20130117130949_add_logo_to_conferences_table.rb
+++ b/db/migrate/20130117130949_add_logo_to_conferences_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddLogoToConferencesTable < ActiveRecord::Migration
   def change
     add_column :conferences, :logo_file_name, :string
diff --git a/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb b/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
index 9872d182..326b9a12 100644
--- a/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
+++ b/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeArrivalRegistrationsDateToDatetime < ActiveRecord::Migration
   def up
     change_column :registrations, :arrival, :datetime
diff --git a/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb b/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
index 9ca53b4c..240e4ed8 100644
--- a/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
+++ b/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMinimumAndMaximumAbstractLengthsToEventTypes < ActiveRecord::Migration
   def change
     add_column :event_types, :minimum_abstract_length, :integer, default: 0
diff --git a/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb b/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
index 50287c31..b0e7a917 100644
--- a/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
+++ b/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDietaryChoiceToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :use_dietary_choices, :boolean, default: false
diff --git a/db/migrate/20130202091051_create_dietary_choices_table.rb b/db/migrate/20130202091051_create_dietary_choices_table.rb
index 464c7250..1ab353d4 100644
--- a/db/migrate/20130202091051_create_dietary_choices_table.rb
+++ b/db/migrate/20130202091051_create_dietary_choices_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateDietaryChoicesTable < ActiveRecord::Migration
   def up
     create_table :dietary_choices do |t|
diff --git a/db/migrate/20130202091229_add_dietary_choice_to_registration.rb b/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
index 5694d206..343de790 100644
--- a/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
+++ b/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDietaryChoiceToRegistration < ActiveRecord::Migration
   def change
     add_column :registrations, :dietary_choice_id, :integer
diff --git a/db/migrate/20130202093137_add_dietary_text_to_registration.rb b/db/migrate/20130202093137_add_dietary_text_to_registration.rb
index 3147cd3c..6a1e356d 100644
--- a/db/migrate/20130202093137_add_dietary_text_to_registration.rb
+++ b/db/migrate/20130202093137_add_dietary_text_to_registration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDietaryTextToRegistration < ActiveRecord::Migration
   def change
     add_column :registrations, :other_dietary_choice, :text
diff --git a/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb b/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
index e98b4e2f..ad5d85da 100644
--- a/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
+++ b/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddHandicappedAccessToRegistrations < ActiveRecord::Migration
   def change
     add_column :registrations, :handicapped_access_required, :boolean, default: false
diff --git a/db/migrate/20130202130737_create_supporter_level_table.rb b/db/migrate/20130202130737_create_supporter_level_table.rb
index 417fe9d0..60e1d08b 100644
--- a/db/migrate/20130202130737_create_supporter_level_table.rb
+++ b/db/migrate/20130202130737_create_supporter_level_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSupporterLevelTable < ActiveRecord::Migration
   def up
     create_table :supporter_levels do |t|
diff --git a/db/migrate/20130202130923_create_table_supporter_registrations.rb b/db/migrate/20130202130923_create_table_supporter_registrations.rb
index 5137ebb9..00f03e64 100644
--- a/db/migrate/20130202130923_create_table_supporter_registrations.rb
+++ b/db/migrate/20130202130923_create_table_supporter_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateTableSupporterRegistrations < ActiveRecord::Migration
   def up
     create_table :supporter_registrations do |t|
diff --git a/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb b/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
index f201511a..53247ccc 100644
--- a/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
+++ b/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUseSupporterLevelsToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :use_supporter_levels, :boolean, default: false
diff --git a/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb b/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
index bb9dc5ad..4ab121de 100644
--- a/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
+++ b/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 class RenameAttendingSocialEventsWithPartner < ActiveRecord::Migration
   def up
     rename_column :registrations, :attending_social_events_with_partner, :attending_with_partner
   end
 
-  def down
-  end
+  def down; end
 end
diff --git a/db/migrate/20130211170728_add_irc_nick_to_people_table.rb b/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
index 36cc5c62..060b85c1 100644
--- a/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
+++ b/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIrcNickToPeopleTable < ActiveRecord::Migration
   def change
     add_column :people, :irc_nickname, :string
diff --git a/db/migrate/20130216070725_create_social_events_table.rb b/db/migrate/20130216070725_create_social_events_table.rb
index 52ebaa06..22f89dbc 100644
--- a/db/migrate/20130216070725_create_social_events_table.rb
+++ b/db/migrate/20130216070725_create_social_events_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSocialEventsTable < ActiveRecord::Migration
   def up
     create_table :social_events do |t|
diff --git a/db/migrate/20130216120112_create_registrations_social_events_table.rb b/db/migrate/20130216120112_create_registrations_social_events_table.rb
index 9a783d4f..a6a98d16 100644
--- a/db/migrate/20130216120112_create_registrations_social_events_table.rb
+++ b/db/migrate/20130216120112_create_registrations_social_events_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateRegistrationsSocialEventsTable < ActiveRecord::Migration
   def up
     create_table :registrations_social_events, id: false do |t|
diff --git a/db/migrate/20130216122155_set_registration_defaults_to_false.rb b/db/migrate/20130216122155_set_registration_defaults_to_false.rb
index bbb45d64..af13b223 100644
--- a/db/migrate/20130216122155_set_registration_defaults_to_false.rb
+++ b/db/migrate/20130216122155_set_registration_defaults_to_false.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 class SetRegistrationDefaultsToFalse < ActiveRecord::Migration
   def up
     change_column :registrations, :using_affiliated_lodging, :boolean, default: false
   end
 
-  def down
-  end
+  def down; end
 end
diff --git a/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb b/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
index 9d438e54..9339819c 100644
--- a/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
+++ b/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSpecialNeedsFieldToRegistrations < ActiveRecord::Migration
   def change
     add_column :registrations, :other_special_needs, :text
diff --git a/db/migrate/20130515125823_change_attachment_default.rb b/db/migrate/20130515125823_change_attachment_default.rb
index 89701f12..4f73cf4d 100644
--- a/db/migrate/20130515125823_change_attachment_default.rb
+++ b/db/migrate/20130515125823_change_attachment_default.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeAttachmentDefault < ActiveRecord::Migration
   def up
     change_column_default(:event_attachments, :public, true)
diff --git a/db/migrate/20130515131420_change_venue_types.rb b/db/migrate/20130515131420_change_venue_types.rb
index f588fe55..00b1cb0a 100644
--- a/db/migrate/20130515131420_change_venue_types.rb
+++ b/db/migrate/20130515131420_change_venue_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeVenueTypes < ActiveRecord::Migration
   def up
     change_column :venues, :name, :text
diff --git a/db/migrate/20130626095459_add_video_id_to_events.rb b/db/migrate/20130626095459_add_video_id_to_events.rb
index 14f034e4..da79497f 100644
--- a/db/migrate/20130626095459_add_video_id_to_events.rb
+++ b/db/migrate/20130626095459_add_video_id_to_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVideoIdToEvents < ActiveRecord::Migration
   def change
     add_column :events, :video_id, :string
diff --git a/db/migrate/20130705055128_add_revision_to_conference.rb b/db/migrate/20130705055128_add_revision_to_conference.rb
index 728b6551..d8e3070c 100644
--- a/db/migrate/20130705055128_add_revision_to_conference.rb
+++ b/db/migrate/20130705055128_add_revision_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRevisionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :revision, :integer
diff --git a/db/migrate/20130711043459_create_events_registrations_table.rb b/db/migrate/20130711043459_create_events_registrations_table.rb
index 0c084a9a..9275880a 100644
--- a/db/migrate/20130711043459_create_events_registrations_table.rb
+++ b/db/migrate/20130711043459_create_events_registrations_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventsRegistrationsTable < ActiveRecord::Migration
   def up
     create_table :events_registrations, id: false do |t|
diff --git a/db/migrate/20130711044247_add_require_registration_to_events.rb b/db/migrate/20130711044247_add_require_registration_to_events.rb
index c89d042d..a4f2f643 100644
--- a/db/migrate/20130711044247_add_require_registration_to_events.rb
+++ b/db/migrate/20130711044247_add_require_registration_to_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRequireRegistrationToEvents < ActiveRecord::Migration
   def change
     add_column :events, :require_registration, :boolean
diff --git a/db/migrate/20130712072609_add_attended_to_registrations.rb b/db/migrate/20130712072609_add_attended_to_registrations.rb
index 3a6f15ee..598f432e 100644
--- a/db/migrate/20130712072609_add_attended_to_registrations.rb
+++ b/db/migrate/20130712072609_add_attended_to_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddAttendedToRegistrations < ActiveRecord::Migration
   def change
     add_column :registrations, :attended, :boolean, default: 0
diff --git a/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb b/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
index d0cabf03..4078efc0 100644
--- a/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
+++ b/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddScheduleChangesToCallForPapers < ActiveRecord::Migration
   def change
     add_column :call_for_papers, :schedule_changes, :boolean, default: 0
diff --git a/db/migrate/20130815085420_create_votes.rb b/db/migrate/20130815085420_create_votes.rb
index 1b4460a7..d0e514a6 100644
--- a/db/migrate/20130815085420_create_votes.rb
+++ b/db/migrate/20130815085420_create_votes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVotes < ActiveRecord::Migration
   def up
     create_table :votes do |t|
diff --git a/db/migrate/20130815201317_add_rating_to_call_for_papers.rb b/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
index 1aab4ac6..b5537596 100644
--- a/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
+++ b/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRatingToCallForPapers < ActiveRecord::Migration
   def change
     add_column :call_for_papers, :rating, :integer, null: 1
diff --git a/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb b/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
index 386a3064..67c8f020 100644
--- a/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
+++ b/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRatingDescToCallForPapers < ActiveRecord::Migration
   def change
     add_column :call_for_papers, :rating_desc, :text
diff --git a/db/migrate/20130821094246_add_volunteer_to_registrations.rb b/db/migrate/20130821094246_add_volunteer_to_registrations.rb
index 98a2e3fe..b0719aab 100644
--- a/db/migrate/20130821094246_add_volunteer_to_registrations.rb
+++ b/db/migrate/20130821094246_add_volunteer_to_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVolunteerToRegistrations < ActiveRecord::Migration
   def change
     add_column :registrations, :volunteer, :boolean
diff --git a/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb b/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
index b725d532..6621e547 100644
--- a/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
+++ b/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVolunteerExperienceToRegistrations < ActiveRecord::Migration
   def change
     add_column :people, :volunteer_experience, :text
diff --git a/db/migrate/20130821102047_add_tshirt_to_people.rb b/db/migrate/20130821102047_add_tshirt_to_people.rb
index 9519dc91..b25b7023 100644
--- a/db/migrate/20130821102047_add_tshirt_to_people.rb
+++ b/db/migrate/20130821102047_add_tshirt_to_people.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTshirtToPeople < ActiveRecord::Migration
   def change
     add_column :people, :tshirt, :string
diff --git a/db/migrate/20130821102108_add_mobile_to_people.rb b/db/migrate/20130821102108_add_mobile_to_people.rb
index f4e9ae68..550b63aa 100644
--- a/db/migrate/20130821102108_add_mobile_to_people.rb
+++ b/db/migrate/20130821102108_add_mobile_to_people.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMobileToPeople < ActiveRecord::Migration
   def change
     add_column :people, :mobile, :string
diff --git a/db/migrate/20130821102404_add_languages_to_people.rb b/db/migrate/20130821102404_add_languages_to_people.rb
index 2ffbbb3b..3d554988 100644
--- a/db/migrate/20130821102404_add_languages_to_people.rb
+++ b/db/migrate/20130821102404_add_languages_to_people.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddLanguagesToPeople < ActiveRecord::Migration
   def change
     add_column :people, :languages, :string
diff --git a/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb b/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
index f78ccd18..25054495 100644
--- a/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
+++ b/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUseVpositionsToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :use_vpositions, :boolean
diff --git a/db/migrate/20130821102618_add_use_vdays_to_conferences.rb b/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
index 70af09c4..ce921316 100644
--- a/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
+++ b/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUseVdaysToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :use_vdays, :boolean
diff --git a/db/migrate/20130821133651_create_vpositions.rb b/db/migrate/20130821133651_create_vpositions.rb
index af7fa36c..dd9d3ed4 100644
--- a/db/migrate/20130821133651_create_vpositions.rb
+++ b/db/migrate/20130821133651_create_vpositions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVpositions < ActiveRecord::Migration
   def up
     create_table :vpositions do |t|
diff --git a/db/migrate/20130821133850_create_vdays.rb b/db/migrate/20130821133850_create_vdays.rb
index c4d83d4c..9c05c279 100644
--- a/db/migrate/20130821133850_create_vdays.rb
+++ b/db/migrate/20130821133850_create_vdays.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVdays < ActiveRecord::Migration
   def up
     create_table :vdays do |t|
diff --git a/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb b/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
index 9ec2317a..bdeede4d 100644
--- a/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
+++ b/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCreatedAtToSupporterRegistrations < ActiveRecord::Migration
   def change
     add_column :supporter_registrations, :created_at, :datetime
diff --git a/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb b/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
index 7fe2f314..89b9fa80 100644
--- a/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
+++ b/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeDefaultRatingInCallForPapers < ActiveRecord::Migration
   def up
     change_column :call_for_papers, :rating, :integer, default: 3
diff --git a/db/migrate/20131228214532_create_vchoices.rb b/db/migrate/20131228214532_create_vchoices.rb
index 04fabb75..0114f532 100644
--- a/db/migrate/20131228214532_create_vchoices.rb
+++ b/db/migrate/20131228214532_create_vchoices.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVchoices < ActiveRecord::Migration
   def change
     create_table :vchoices do |t|
diff --git a/db/migrate/20131229072532_registrations_vchoices.rb b/db/migrate/20131229072532_registrations_vchoices.rb
index 1c25a32f..3110ea2e 100644
--- a/db/migrate/20131229072532_registrations_vchoices.rb
+++ b/db/migrate/20131229072532_registrations_vchoices.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RegistrationsVchoices < ActiveRecord::Migration
   def up
     create_table :registrations_vchoices, id: false do |t|
diff --git a/db/migrate/20140109190643_create_questions.rb b/db/migrate/20140109190643_create_questions.rb
index e0272cdb..e78b4d20 100644
--- a/db/migrate/20140109190643_create_questions.rb
+++ b/db/migrate/20140109190643_create_questions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateQuestions < ActiveRecord::Migration
   def change
     create_table :questions do |t|
diff --git a/db/migrate/20140109190844_create_question_types.rb b/db/migrate/20140109190844_create_question_types.rb
index 3a2582fd..7a8f07d3 100644
--- a/db/migrate/20140109190844_create_question_types.rb
+++ b/db/migrate/20140109190844_create_question_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateQuestionTypes < ActiveRecord::Migration
   def change
     create_table :question_types do |t|
diff --git a/db/migrate/20140109191042_create_answers.rb b/db/migrate/20140109191042_create_answers.rb
index 35394d79..5356bda7 100644
--- a/db/migrate/20140109191042_create_answers.rb
+++ b/db/migrate/20140109191042_create_answers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateAnswers < ActiveRecord::Migration
   def change
     create_table :answers do |t|
diff --git a/db/migrate/20140109191145_create_qanswers.rb b/db/migrate/20140109191145_create_qanswers.rb
index 4b31744f..4bc39588 100644
--- a/db/migrate/20140109191145_create_qanswers.rb
+++ b/db/migrate/20140109191145_create_qanswers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateQanswers < ActiveRecord::Migration
   def change
     create_table :qanswers do |t|
diff --git a/db/migrate/20140109191321_create_conferences_questions.rb b/db/migrate/20140109191321_create_conferences_questions.rb
index 7cb8dbaf..659de9a4 100644
--- a/db/migrate/20140109191321_create_conferences_questions.rb
+++ b/db/migrate/20140109191321_create_conferences_questions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateConferencesQuestions < ActiveRecord::Migration
   def change
     create_table :conferences_questions, id: false do |t|
diff --git a/db/migrate/20140112192801_create_qanswers_registrations.rb b/db/migrate/20140112192801_create_qanswers_registrations.rb
index e523173a..9501defe 100644
--- a/db/migrate/20140112192801_create_qanswers_registrations.rb
+++ b/db/migrate/20140112192801_create_qanswers_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateQanswersRegistrations < ActiveRecord::Migration
   def change
     create_table :qanswers_registrations, id: false do |t|
diff --git a/db/migrate/20140212172244_create_difficulty_levels.rb b/db/migrate/20140212172244_create_difficulty_levels.rb
index bdd9547c..02faced0 100644
--- a/db/migrate/20140212172244_create_difficulty_levels.rb
+++ b/db/migrate/20140212172244_create_difficulty_levels.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateDifficultyLevels < ActiveRecord::Migration
   def change
     create_table :difficulty_levels do |t|
diff --git a/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb b/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
index c60721e4..02391e2a 100644
--- a/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
+++ b/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUseDifficultyLevelsToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :use_difficulty_levels, :boolean, default: false
diff --git a/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb b/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
index 56bcecb6..e4594d1e 100644
--- a/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
+++ b/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDifficultyLevelIdToEvents < ActiveRecord::Migration
   def change
     add_column :events, :difficulty_level_id, :integer
diff --git a/db/migrate/20140304192527_add_use_volunteers_to_conference.rb b/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
index 568aeec5..d7c030fa 100644
--- a/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
+++ b/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUseVolunteersToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :use_volunteers, :boolean
diff --git a/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb b/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
index 4ab07be9..052ea315 100644
--- a/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
+++ b/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UseVdaysVpositionsDefaults < ActiveRecord::Migration
   def up
     change_column :conferences, :use_vpositions, :boolean, default: false
diff --git a/db/migrate/20140319143547_rename_video_to_media_on_events.rb b/db/migrate/20140319143547_rename_video_to_media_on_events.rb
index 754c8af4..f5d6d771 100644
--- a/db/migrate/20140319143547_rename_video_to_media_on_events.rb
+++ b/db/migrate/20140319143547_rename_video_to_media_on_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameVideoToMediaOnEvents < ActiveRecord::Migration
   def up
     rename_column :events, :video_id, :media_id
diff --git a/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb b/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
index f08d925c..fb82814f 100644
--- a/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
+++ b/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSchedulePublicToCallForPapers < ActiveRecord::Migration
   def change
     add_column :call_for_papers, :schedule_public, :boolean
diff --git a/db/migrate/20140414131028_add_video_to_conferences.rb b/db/migrate/20140414131028_add_video_to_conferences.rb
index 3fbe01b8..ea781109 100644
--- a/db/migrate/20140414131028_add_video_to_conferences.rb
+++ b/db/migrate/20140414131028_add_video_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVideoToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :media_id, :string
diff --git a/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb b/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
index c8bd9bb4..8f25368d 100644
--- a/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
+++ b/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveRatingDescFromCfp < ActiveRecord::Migration
   def up
     remove_column :call_for_papers, :rating_desc
diff --git a/db/migrate/20140528072939_add_color_to_conference.rb b/db/migrate/20140528072939_add_color_to_conference.rb
index c3f83980..37aa6f99 100644
--- a/db/migrate/20140528072939_add_color_to_conference.rb
+++ b/db/migrate/20140528072939_add_color_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddColorToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :color, :string, default: '#000000'
diff --git a/db/migrate/20140528084706_add_description_to_conference.rb b/db/migrate/20140528084706_add_description_to_conference.rb
index 0cb7291d..9e1612fc 100644
--- a/db/migrate/20140528084706_add_description_to_conference.rb
+++ b/db/migrate/20140528084706_add_description_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDescriptionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :description, :text
diff --git a/db/migrate/20140528115842_add_registration_description_to_conference.rb b/db/migrate/20140528115842_add_registration_description_to_conference.rb
index b893de72..3886549a 100644
--- a/db/migrate/20140528115842_add_registration_description_to_conference.rb
+++ b/db/migrate/20140528115842_add_registration_description_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRegistrationDescriptionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :registration_description, :text
diff --git a/db/migrate/20140529133052_add_ticket_description_to_conference.rb b/db/migrate/20140529133052_add_ticket_description_to_conference.rb
index ccb610d9..bbd4b997 100644
--- a/db/migrate/20140529133052_add_ticket_description_to_conference.rb
+++ b/db/migrate/20140529133052_add_ticket_description_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTicketDescriptionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :ticket_description, :text
diff --git a/db/migrate/20140529133228_add_description_to_supporter_level.rb b/db/migrate/20140529133228_add_description_to_supporter_level.rb
index 4473c851..68b04806 100644
--- a/db/migrate/20140529133228_add_description_to_supporter_level.rb
+++ b/db/migrate/20140529133228_add_description_to_supporter_level.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDescriptionToSupporterLevel < ActiveRecord::Migration
   def change
     add_column :supporter_levels, :description, :text
diff --git a/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb b/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
index c7ac5002..cc993529 100644
--- a/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
+++ b/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTicketPriceToSupporterLevel < ActiveRecord::Migration
   def change
     add_column :supporter_levels, :ticket_price, :string
diff --git a/db/migrate/20140530082708_remove_color_defaults.rb b/db/migrate/20140530082708_remove_color_defaults.rb
index 4292ecca..d5b7fe50 100644
--- a/db/migrate/20140530082708_remove_color_defaults.rb
+++ b/db/migrate/20140530082708_remove_color_defaults.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveColorDefaults < ActiveRecord::Migration
   def change
     change_column_default(:tracks, :color, nil)
diff --git a/db/migrate/20140603092041_create_openids.rb b/db/migrate/20140603092041_create_openids.rb
index 4ca63029..93cf271d 100644
--- a/db/migrate/20140603092041_create_openids.rb
+++ b/db/migrate/20140603092041_create_openids.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateOpenids < ActiveRecord::Migration
   def change
     create_table :openids do |t|
diff --git a/db/migrate/20140604061951_create_lodgings.rb b/db/migrate/20140604061951_create_lodgings.rb
index 45412bcc..e9192e33 100644
--- a/db/migrate/20140604061951_create_lodgings.rb
+++ b/db/migrate/20140604061951_create_lodgings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateLodgings < ActiveRecord::Migration
   def change
     create_table :lodgings do |t|
diff --git a/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb b/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
index 7d567199..b1e3d052 100644
--- a/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
+++ b/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveHardDeadlineFromCallForPapers < ActiveRecord::Migration
   def up
     remove_column :call_for_papers, :hard_deadline
diff --git a/db/migrate/20140605055802_create_sponsorship_levels.rb b/db/migrate/20140605055802_create_sponsorship_levels.rb
index 1a93980b..e192b2c1 100644
--- a/db/migrate/20140605055802_create_sponsorship_levels.rb
+++ b/db/migrate/20140605055802_create_sponsorship_levels.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSponsorshipLevels < ActiveRecord::Migration
   def change
     create_table :sponsorship_levels do |t|
diff --git a/db/migrate/20140605115251_create_sponsors.rb b/db/migrate/20140605115251_create_sponsors.rb
index 0c3bd063..fb2751d2 100644
--- a/db/migrate/20140605115251_create_sponsors.rb
+++ b/db/migrate/20140605115251_create_sponsors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSponsors < ActiveRecord::Migration
   def change
     create_table :sponsors do |t|
diff --git a/db/migrate/20140605125153_update_event_states.rb b/db/migrate/20140605125153_update_event_states.rb
index b4a888c6..e5302c8e 100644
--- a/db/migrate/20140605125153_update_event_states.rb
+++ b/db/migrate/20140605125153_update_event_states.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UpdateEventStates < ActiveRecord::Migration
   def change
     execute "UPDATE events SET state='new' WHERE state = 'review';"
diff --git a/db/migrate/20140606102331_add_sponsor_description_to_conference.rb b/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
index 39d6de6e..eb01d770 100644
--- a/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
+++ b/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSponsorDescriptionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :sponsor_description, :text
diff --git a/db/migrate/20140606102358_add_sponsor_email_to_conference.rb b/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
index 7dc0b56e..7446746b 100644
--- a/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
+++ b/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSponsorEmailToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :sponsor_email, :string
diff --git a/db/migrate/20140609172219_add_person_attributes_to_user.rb b/db/migrate/20140609172219_add_person_attributes_to_user.rb
index 140d7771..e9b1fcee 100644
--- a/db/migrate/20140609172219_add_person_attributes_to_user.rb
+++ b/db/migrate/20140609172219_add_person_attributes_to_user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPersonAttributesToUser < ActiveRecord::Migration
   def change
     add_column :users, :name, :string
diff --git a/db/migrate/20140610064046_create_photos.rb b/db/migrate/20140610064046_create_photos.rb
index 846b7934..5e1aab05 100644
--- a/db/migrate/20140610064046_create_photos.rb
+++ b/db/migrate/20140610064046_create_photos.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreatePhotos < ActiveRecord::Migration
   def change
     create_table :photos do |t|
diff --git a/db/migrate/20140610163947_create_event_users.rb b/db/migrate/20140610163947_create_event_users.rb
index 7d0fdbe3..668b3006 100644
--- a/db/migrate/20140610163947_create_event_users.rb
+++ b/db/migrate/20140610163947_create_event_users.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 class CreateEventUsers < ActiveRecord::Migration
-  class TempPerson < ActiveRecord::Base
+  class TempPerson < ApplicationRecord
     self.table_name = 'people'
   end
 
-  class TempEventPerson < ActiveRecord::Base
+  class TempEventPerson < ApplicationRecord
     self.table_name = 'event_people'
   end
 
-  class TempEventUser < ActiveRecord::Base
+  class TempEventUser < ApplicationRecord
     self.table_name = 'event_users'
   end
 
diff --git a/db/migrate/20140610165551_migrate_data_person_to_user.rb b/db/migrate/20140610165551_migrate_data_person_to_user.rb
index d606ba28..7743b324 100644
--- a/db/migrate/20140610165551_migrate_data_person_to_user.rb
+++ b/db/migrate/20140610165551_migrate_data_person_to_user.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class MigrateDataPersonToUser < ActiveRecord::Migration
-  class TempPerson < ActiveRecord::Base
+  class TempPerson < ApplicationRecord
     self.table_name = 'people'
   end
 
-  class TempUser < ActiveRecord::Base
+  class TempUser < ApplicationRecord
     self.table_name = 'users'
   end
 
@@ -11,11 +13,11 @@ class MigrateDataPersonToUser < ActiveRecord::Migration
     TempPerson.all.each do |p|
       user = TempUser.find_by(id: p.user_id)
       next unless user
-      if p.public_name.empty?
-        user.name = p.email
-      else
-        user.name = p.public_name
-      end
+      user.name = if p.public_name.empty?
+                    p.email
+                  else
+                    p.public_name
+                  end
       user.biography = p.biography
       user.nickname = p.irc_nickname
       user.affiliation = p.company
diff --git a/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb b/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
index ac54e435..d592a118 100644
--- a/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
+++ b/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class ChangePersonIdToUserIdInRegistrations < ActiveRecord::Migration
-  class TempPerson < ActiveRecord::Base
+  class TempPerson < ApplicationRecord
     self.table_name = 'people'
   end
 
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
   end
 
@@ -13,11 +15,10 @@ class ChangePersonIdToUserIdInRegistrations < ActiveRecord::Migration
     TempPerson.all.each do |t|
       registrations = TempRegistration.where(person_id: t.id)
 
-      unless registrations.empty?
-        registrations.each do |r|
-          r.user_id = t.user_id
-          r.save!
-        end
+      next if registrations.empty?
+      registrations.each do |r|
+        r.user_id = t.user_id
+        r.save!
       end
     end
 
diff --git a/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb b/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
index 973f0001..7073d345 100644
--- a/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
+++ b/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class ChangePersonIdToUserIdInVotes < ActiveRecord::Migration
-  class TempPerson < ActiveRecord::Base
+  class TempPerson < ApplicationRecord
     self.table_name = 'people'
   end
 
-  class TempVote < ActiveRecord::Base
+  class TempVote < ApplicationRecord
     self.table_name = 'votes'
   end
 
@@ -13,11 +15,10 @@ class ChangePersonIdToUserIdInVotes < ActiveRecord::Migration
     TempPerson.all.each do |t|
       votes = TempVote.where(person_id: t.id)
 
-      unless votes.empty?
-        votes.each do |v|
-          v.user_id = t.user_id
-          v.save!
-        end
+      next if votes.empty?
+      votes.each do |v|
+        v.user_id = t.user_id
+        v.save!
       end
     end
 
diff --git a/db/migrate/20140612141123_add_color_to_event_type.rb b/db/migrate/20140612141123_add_color_to_event_type.rb
index 210256ea..ffe250a4 100644
--- a/db/migrate/20140612141123_add_color_to_event_type.rb
+++ b/db/migrate/20140612141123_add_color_to_event_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddColorToEventType < ActiveRecord::Migration
   def change
     add_column :event_types, :color, :string
diff --git a/db/migrate/20140612181230_add_social_urls_to_conference.rb b/db/migrate/20140612181230_add_social_urls_to_conference.rb
index 5144cbd2..44cd3373 100644
--- a/db/migrate/20140612181230_add_social_urls_to_conference.rb
+++ b/db/migrate/20140612181230_add_social_urls_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSocialUrlsToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :twitter_url, :string
diff --git a/db/migrate/20140613083115_add_photo_to_venue.rb b/db/migrate/20140613083115_add_photo_to_venue.rb
index c2d0454c..8d2f7a52 100644
--- a/db/migrate/20140613083115_add_photo_to_venue.rb
+++ b/db/migrate/20140613083115_add_photo_to_venue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPhotoToVenue < ActiveRecord::Migration
   def change
     add_column :venues, :photo_file_name, :string
diff --git a/db/migrate/20140614171853_add_lodging_description_to_conference.rb b/db/migrate/20140614171853_add_lodging_description_to_conference.rb
index 37dd2c30..7e34573a 100644
--- a/db/migrate/20140614171853_add_lodging_description_to_conference.rb
+++ b/db/migrate/20140614171853_add_lodging_description_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddLodgingDescriptionToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :lodging_description, :text
diff --git a/db/migrate/20140614174354_add_website_link_to_lodging.rb b/db/migrate/20140614174354_add_website_link_to_lodging.rb
index 63c37bb3..d7f6d809 100644
--- a/db/migrate/20140614174354_add_website_link_to_lodging.rb
+++ b/db/migrate/20140614174354_add_website_link_to_lodging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddWebsiteLinkToLodging < ActiveRecord::Migration
   def change
     add_column :lodgings, :website_link, :string
diff --git a/db/migrate/20140616131731_add_make_conference_public_to_conference.rb b/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
index 9cf9195b..20c41a52 100644
--- a/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
+++ b/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMakeConferencePublicToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :make_conference_public, :boolean, default: false
diff --git a/db/migrate/20140616132153_create_targets.rb b/db/migrate/20140616132153_create_targets.rb
index 0295816e..3f5e4b7e 100644
--- a/db/migrate/20140616132153_create_targets.rb
+++ b/db/migrate/20140616132153_create_targets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateTargets < ActiveRecord::Migration
   def change
     create_table :targets do |t|
diff --git a/db/migrate/20140616132456_create_campaigns.rb b/db/migrate/20140616132456_create_campaigns.rb
index 9e696b68..edb06d58 100644
--- a/db/migrate/20140616132456_create_campaigns.rb
+++ b/db/migrate/20140616132456_create_campaigns.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateCampaigns < ActiveRecord::Migration
   def change
     create_table :campaigns do |t|
diff --git a/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb b/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
index 5822c6cd..a716507c 100644
--- a/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
+++ b/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCheckboxesForSplashComponentsToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :include_registrations_in_splash, :boolean, default: false
diff --git a/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb b/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
index 415927e4..e8ab8e23 100644
--- a/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
+++ b/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIncludeCfpInSplashToCallForPapers < ActiveRecord::Migration
   def change
     add_column :call_for_papers, :include_cfp_in_splash, :boolean, default: false
diff --git a/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb b/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
index eeb7bfea..fc6d82d3 100644
--- a/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
+++ b/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVenueCheckboxesToVenue < ActiveRecord::Migration
   def change
     add_column :venues, :include_venue_in_splash, :boolean, default: false
diff --git a/db/migrate/20140620130306_add_banner_photo_to_conference.rb b/db/migrate/20140620130306_add_banner_photo_to_conference.rb
index 37b66b6e..c6ca6ecc 100644
--- a/db/migrate/20140620130306_add_banner_photo_to_conference.rb
+++ b/db/migrate/20140620130306_add_banner_photo_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddBannerPhotoToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :banner_photo_file_name, :string
diff --git a/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb b/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
index 99e72412..229172ea 100644
--- a/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
+++ b/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIncludeBannerInSplashToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :include_banner_in_splash, :boolean, default: false
diff --git a/db/migrate/20140623100942_create_visits.rb b/db/migrate/20140623100942_create_visits.rb
index 561fa177..49d409b6 100644
--- a/db/migrate/20140623100942_create_visits.rb
+++ b/db/migrate/20140623100942_create_visits.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateVisits < ActiveRecord::Migration
   def change
     create_table :visits do |t|
diff --git a/db/migrate/20140623101032_create_ahoy_events.rb b/db/migrate/20140623101032_create_ahoy_events.rb
index c865a59c..7e873a75 100644
--- a/db/migrate/20140623101032_create_ahoy_events.rb
+++ b/db/migrate/20140623101032_create_ahoy_events.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 class CreateAhoyEvents < ActiveRecord::Migration
   def change
-    create_table :ahoy_events  do |t|
+    create_table :ahoy_events do |t|
       t.uuid :visit_id
       # user
       t.integer :user_id
diff --git a/db/migrate/20140623150541_drop_person_and_event_person_tables.rb b/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
index d83ae15b..779f4450 100644
--- a/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
+++ b/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DropPersonAndEventPersonTables < ActiveRecord::Migration
   def change
     drop_table :people
diff --git a/db/migrate/20140625112608_add_week_to_event.rb b/db/migrate/20140625112608_add_week_to_event.rb
index 72d05389..a5f45bbc 100644
--- a/db/migrate/20140625112608_add_week_to_event.rb
+++ b/db/migrate/20140625112608_add_week_to_event.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddWeekToEvent < ActiveRecord::Migration
-  class Event < ActiveRecord::Base
+  class Event < ApplicationRecord
   end
 
   def up
diff --git a/db/migrate/20140625114813_add_week_to_registration.rb b/db/migrate/20140625114813_add_week_to_registration.rb
index 29484a79..14b97c4a 100644
--- a/db/migrate/20140625114813_add_week_to_registration.rb
+++ b/db/migrate/20140625114813_add_week_to_registration.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddWeekToRegistration < ActiveRecord::Migration
-  class Registration < ActiveRecord::Base
+  class Registration < ApplicationRecord
   end
 
   def up
diff --git a/db/migrate/20140627165718_add_instagram_url_to_conference.rb b/db/migrate/20140627165718_add_instagram_url_to_conference.rb
index d405bbc4..bb6859d9 100644
--- a/db/migrate/20140627165718_add_instagram_url_to_conference.rb
+++ b/db/migrate/20140627165718_add_instagram_url_to_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddInstagramUrlToConference < ActiveRecord::Migration
   def change
     add_column :conferences, :instagram_url, :string
diff --git a/db/migrate/20140701123203_add_events_per_week_to_conference.rb b/db/migrate/20140701123203_add_events_per_week_to_conference.rb
index 2b4d3342..646ac9ea 100644
--- a/db/migrate/20140701123203_add_events_per_week_to_conference.rb
+++ b/db/migrate/20140701123203_add_events_per_week_to_conference.rb
@@ -1,14 +1,16 @@
+# frozen_string_literal: true
+
 class AddEventsPerWeekToConference < ActiveRecord::Migration
-  class TempVersion < ActiveRecord::Base
+  class TempVersion < ApplicationRecord
     self.table_name = 'versions'
     serialize :object_changes, HashWithIndifferentAccess
   end
 
-  class TempEvent < ActiveRecord::Base
+  class TempEvent < ApplicationRecord
     self.table_name = 'events'
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
     serialize :events_per_week, Hash
   end
@@ -18,56 +20,54 @@ class AddEventsPerWeekToConference < ActiveRecord::Migration
     TempConference.reset_column_information
 
     TempVersion.where(item_type: 'Event').each do |event_version|
-      event = TempEvent.find_by_id(event_version.item_id)
-      if event
-        conference = TempConference.find_by_id(event.conference_id)
-        if conference
-          week = event_version.created_at.end_of_week
+      event = TempEvent.find_by(id: event_version.item_id)
+      next unless event
+      conference = TempConference.find_by(id: event.conference_id)
+      next unless conference
+      week = event_version.created_at.end_of_week
 
-          no_events = {
-              new: 0,
-              withdrawn: 0,
-              unconfirmed: 0,
-              confirmed: 0,
-              canceled: 0,
-              rejected: 0,
-          }
+      no_events = {
+        new: 0,
+        withdrawn: 0,
+        unconfirmed: 0,
+        confirmed: 0,
+        canceled: 0,
+        rejected: 0
+      }
 
-          if !conference.events_per_week
-            conference.events_per_week = {
-                week => no_events
-            }
-          elsif !conference.events_per_week[week]
-            conference.events_per_week[week] = no_events
-          end
-
-          if event_version.object_changes &&
-              event_version.event == 'create'
-
-            # Increment the new state
-            conference.events_per_week[week][:new] += 1
-          elsif event_version.object_changes &&
-              event_version.object_changes[:state]
-
-            prev_state = event_version.object_changes[:state][0].to_sym
-            next_state = event_version.object_changes[:state][1].to_sym
-
-            # Backward compatibility: deprecated state :review now :new
-            if prev_state == :review
-              prev_state = :new
-            elsif  next_state == :review
-              next_state = :new
-            end
-
-            # Increment the next state
-            conference.events_per_week[week][next_state] += 1
-
-            # Decrement the previous state
-            conference.events_per_week[week][prev_state] -= 1
-          end
-          conference.save
-        end
+      if !conference.events_per_week
+        conference.events_per_week = {
+          week => no_events
+        }
+      elsif !conference.events_per_week[week]
+        conference.events_per_week[week] = no_events
       end
+
+      if event_version.object_changes &&
+         event_version.event == 'create'
+
+        # Increment the new state
+        conference.events_per_week[week][:new] += 1
+      elsif event_version.object_changes &&
+            event_version.object_changes[:state]
+
+        prev_state = event_version.object_changes[:state][0].to_sym
+        next_state = event_version.object_changes[:state][1].to_sym
+
+        # Backward compatibility: deprecated state :review now :new
+        if prev_state == :review
+          prev_state = :new
+        elsif next_state == :review
+          next_state = :new
+        end
+
+        # Increment the next state
+        conference.events_per_week[week][next_state] += 1
+
+        # Decrement the previous state
+        conference.events_per_week[week][prev_state] -= 1
+      end
+      conference.save
     end
 
     # Cumulate the previous weeks to get a snapshot
diff --git a/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb b/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
index 24889597..6755eb36 100644
--- a/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
+++ b/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddConferenceDatesUpdatesToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :send_on_updated_conference_dates, :boolean, default: true
diff --git a/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb b/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
index 6313619b..6c33a5a3 100644
--- a/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
+++ b/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddConferenceRegistrationDatesUpdatesToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :send_on_updated_conference_registration_dates, :boolean, default: true
diff --git a/db/migrate/20140711072651_add_description_and_resource_to_roles.rb b/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
index 8e5a16ec..7243d268 100644
--- a/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
+++ b/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 class AddDescriptionAndResourceToRoles < ActiveRecord::Migration
   def change
     add_column :roles, :description, :string
     add_reference :roles, :resource, polymorphic: true
 
     add_index(:roles, :name)
-    add_index(:roles, [:name, :resource_type, :resource_id])
-    add_index(:roles_users, [:user_id, :role_id])
+    add_index(:roles, %i[name resource_type resource_id])
+    add_index(:roles_users, %i[user_id role_id])
   end
 end
diff --git a/db/migrate/20140711113037_add_venue_update_to_email_settings.rb b/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
index 9280181b..a03d1704 100644
--- a/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
+++ b/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVenueUpdateToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :send_on_venue_update, :boolean, default: true
diff --git a/db/migrate/20140714141156_add_volunteer_fields_to_user.rb b/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
index cf69a37f..293b179d 100644
--- a/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
+++ b/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVolunteerFieldsToUser < ActiveRecord::Migration
   def change
     add_column :users, :mobile, :string
diff --git a/db/migrate/20140716115448_add_default_value_to_email_settings.rb b/db/migrate/20140716115448_add_default_value_to_email_settings.rb
index 947aca55..404219fa 100644
--- a/db/migrate/20140716115448_add_default_value_to_email_settings.rb
+++ b/db/migrate/20140716115448_add_default_value_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDefaultValueToEmailSettings < ActiveRecord::Migration
   def up
     change_column :email_settings, :send_on_registration, :boolean, default: false
diff --git a/db/migrate/20140718103856_add_is_admin_to_users.rb b/db/migrate/20140718103856_add_is_admin_to_users.rb
index 1511d822..de524058 100644
--- a/db/migrate/20140718103856_add_is_admin_to_users.rb
+++ b/db/migrate/20140718103856_add_is_admin_to_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIsAdminToUsers < ActiveRecord::Migration
   def change
     add_column :users, :is_admin, :boolean, default: false
diff --git a/db/migrate/20140719160903_create_delayed_jobs.rb b/db/migrate/20140719160903_create_delayed_jobs.rb
index ee7515c2..e9e32d0f 100644
--- a/db/migrate/20140719160903_create_delayed_jobs.rb
+++ b/db/migrate/20140719160903_create_delayed_jobs.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class CreateDelayedJobs < ActiveRecord::Migration
   def self.up
     create_table :delayed_jobs, force: true do |table|
       table.integer  :priority, default: 0, null: false # Allows some jobs to jump to the front of the queue
       table.integer  :attempts, default: 0, null: false # Provides for retries, but still fail eventually.
-      table.text     :handler, null: false                 # YAML-encoded string of the object that will do work
+      table.text     :handler, null: false # YAML-encoded string of the object that will do work
       table.text     :last_error                              # reason for last failure (See Note below)
       table.datetime :run_at                                  # When to run. Could be Time.zone.now for immediately, or sometime in the future.
       table.datetime :locked_at                               # Set when a client is working on this object
@@ -13,7 +15,7 @@ class CreateDelayedJobs < ActiveRecord::Migration
       table.timestamps
     end
 
-    add_index :delayed_jobs, [:priority, :run_at], name: 'delayed_jobs_priority'
+    add_index :delayed_jobs, %i[priority run_at], name: 'delayed_jobs_priority'
   end
 
   def self.down
diff --git a/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb b/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
index b7f0e6bb..dc4206b3 100644
--- a/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
+++ b/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCallForPapersUpdatesToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :send_on_call_for_papers_dates_updates, :boolean, default: false
diff --git a/db/migrate/20140724153520_create_subscriptions.rb b/db/migrate/20140724153520_create_subscriptions.rb
index 25124489..80a246df 100644
--- a/db/migrate/20140724153520_create_subscriptions.rb
+++ b/db/migrate/20140724153520_create_subscriptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSubscriptions < ActiveRecord::Migration
   def change
     create_table :subscriptions do |t|
diff --git a/db/migrate/20140730104658_migrate_roles_for_cancancan.rb b/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
index d4259863..04f93632 100644
--- a/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
+++ b/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MigrateRolesForCancancan < ActiveRecord::Migration
   def up
     # Store the number of existing roles
@@ -17,12 +19,10 @@ class MigrateRolesForCancancan < ActiveRecord::Migration
     end
 
     # Delete old roles
-    Role.first(old_roles).each do |role|
-      role.destroy
-    end
+    Role.first(old_roles).each(&:destroy)
   end
 
   def down
-    raise ActiveRecord::IrreversibleMigration.new('Cannot reverse migration.')
+    raise ActiveRecord::IrreversibleMigration, 'Cannot reverse migration.'
   end
 end
diff --git a/db/migrate/20140731153332_create_contacts.rb b/db/migrate/20140731153332_create_contacts.rb
index df1b3ce7..db76cd09 100644
--- a/db/migrate/20140731153332_create_contacts.rb
+++ b/db/migrate/20140731153332_create_contacts.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateContacts < ActiveRecord::Migration
   def change
     create_table :contacts do |t|
diff --git a/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb b/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
index 6098c024..97dce34b 100644
--- a/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
+++ b/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
@@ -1,25 +1,26 @@
+# frozen_string_literal: true
+
 class MoveConferenceContactDetailsToContact < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempContact < ActiveRecord::Base
+  class TempContact < ApplicationRecord
     self.table_name = 'contacts'
   end
 
   def change
     # Move all the settings to the new object
     TempConference.all.each do |conference|
-      unless TempContact.exists?(conference_id: conference.id)
-        TempContact.create(social_tag: conference.social_tag,
-                           email: conference.contact_email,
-                           facebook: conference.facebook_url,
-                           googleplus: conference.google_url,
-                           twitter: conference.twitter_url,
-                           instagram: conference.instagram_url,
-                           public: conference.include_social_media_in_splash,
-                           conference_id: conference.id)
-      end
+      next if TempContact.exists?(conference_id: conference.id)
+      TempContact.create(social_tag: conference.social_tag,
+                         email: conference.contact_email,
+                         facebook: conference.facebook_url,
+                         googleplus: conference.google_url,
+                         twitter: conference.twitter_url,
+                         instagram: conference.instagram_url,
+                         public: conference.include_social_media_in_splash,
+                         conference_id: conference.id)
     end
     # Then remove all the columns
     remove_column :conferences, :social_tag
diff --git a/db/migrate/20140801103645_create_commercials.rb b/db/migrate/20140801103645_create_commercials.rb
index 62074a6f..bc73fb82 100644
--- a/db/migrate/20140801103645_create_commercials.rb
+++ b/db/migrate/20140801103645_create_commercials.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateCommercials < ActiveRecord::Migration
   def change
     create_table :commercials do |t|
diff --git a/db/migrate/20140801164901_move_conference_media_to_commercial.rb b/db/migrate/20140801164901_move_conference_media_to_commercial.rb
index d22f541c..5baf1e62 100644
--- a/db/migrate/20140801164901_move_conference_media_to_commercial.rb
+++ b/db/migrate/20140801164901_move_conference_media_to_commercial.rb
@@ -1,23 +1,23 @@
+# frozen_string_literal: true
+
 class MoveConferenceMediaToCommercial < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempCommercial < ActiveRecord::Base
+  class TempCommercial < ApplicationRecord
     self.table_name = 'commercials'
   end
 
   def change
     # Move all the settings to the new object
     TempConference.all.each do |conference|
-      unless TempCommercial.exists?(commercialable_id: conference.id, commercialable_id: 'Conference')
-        unless conference.media_id.blank? || conference.media_type.blank?
-          TempCommercial.create(commercial_id: conference.media_id,
-                                commercial_type: conference.media_type,
-                                commercialable_id: conference.id,
-                                commercialable_type: 'Conference')
-        end
-      end
+      next if TempCommercial.exists?(commercialable_id: conference.id, commercialable_id: 'Conference')
+      next if conference.media_id.blank? || conference.media_type.blank?
+      TempCommercial.create(commercial_id: conference.media_id,
+                            commercial_type: conference.media_type,
+                            commercialable_id: conference.id,
+                            commercialable_type: 'Conference')
     end
 
     # Then remove all the columns
diff --git a/db/migrate/20140801170430_move_event_media_to_commercial.rb b/db/migrate/20140801170430_move_event_media_to_commercial.rb
index b4fdc16f..0093c4b3 100644
--- a/db/migrate/20140801170430_move_event_media_to_commercial.rb
+++ b/db/migrate/20140801170430_move_event_media_to_commercial.rb
@@ -1,23 +1,23 @@
+# frozen_string_literal: true
+
 class MoveEventMediaToCommercial < ActiveRecord::Migration
-  class TempEvent < ActiveRecord::Base
+  class TempEvent < ApplicationRecord
     self.table_name = 'events'
   end
 
-  class TempCommercial < ActiveRecord::Base
+  class TempCommercial < ApplicationRecord
     self.table_name = 'commercials'
   end
 
   def change
     # Move all the settings to the new object
     TempEvent.all.each do |event|
-      unless TempCommercial.exists?(commercialable_id: event.id, commercialable_id: 'Conference')
-        unless event.media_id.blank? || event.media_type.blank?
-          TempCommercial.create(commercial_id: event.media_id,
-                                commercial_type: event.media_type,
-                                commercialable_id: event.id,
-                                commercialable_type: 'Event')
-        end
-      end
+      next if TempCommercial.exists?(commercialable_id: event.id, commercialable_id: 'Conference')
+      next if event.media_id.blank? || event.media_type.blank?
+      TempCommercial.create(commercial_id: event.media_id,
+                            commercial_type: event.media_type,
+                            commercialable_id: event.id,
+                            commercialable_type: 'Event')
     end
 
     # Then remove all the columns
diff --git a/db/migrate/20140804185823_create_registration_periods.rb b/db/migrate/20140804185823_create_registration_periods.rb
index 4906144a..e8814623 100644
--- a/db/migrate/20140804185823_create_registration_periods.rb
+++ b/db/migrate/20140804185823_create_registration_periods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateRegistrationPeriods < ActiveRecord::Migration
   def up
     create_table :registration_periods do |t|
diff --git a/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb b/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
index 7d86ae75..7bac1ece 100644
--- a/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
+++ b/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
@@ -1,21 +1,22 @@
+# frozen_string_literal: true
+
 class MoveConferenceRegistrationDataToRegistrationPeriods < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempRegistrationPeriod < ActiveRecord::Base
+  class TempRegistrationPeriod < ApplicationRecord
     self.table_name = 'registration_periods'
   end
 
   def up
     # Move all the settings to the new object
     TempConference.all.each do |conference|
-      unless TempRegistrationPeriod.exists?(conference_id: conference.id)
-        TempRegistrationPeriod.create(conference_id: conference.id,
-                                      start_date: conference.registration_start_date,
-                                      end_date: conference.registration_end_date,
-                                      description: conference.registration_description)
-      end
+      next if TempRegistrationPeriod.exists?(conference_id: conference.id)
+      TempRegistrationPeriod.create(conference_id: conference.id,
+                                    start_date: conference.registration_start_date,
+                                    end_date: conference.registration_end_date,
+                                    description: conference.registration_description)
     end
 
     # Remove Columns
diff --git a/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb b/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
index 38fb10b6..c88ccba5 100644
--- a/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
+++ b/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameSupporterLevelToTicket < ActiveRecord::Migration
   def up
     rename_table :supporter_levels, :tickets
diff --git a/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb b/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
index 8be20de2..6baf22f2 100644
--- a/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
+++ b/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 class MigratingSupporterRegistrationsToTicketUsers < ActiveRecord::Migration
-  class TempSupporterRegistrations < ActiveRecord::Base
+  class TempSupporterRegistrations < ApplicationRecord
     self.table_name = 'supporter_registrations'
   end
 
-  class TempUser < ActiveRecord::Base
+  class TempUser < ApplicationRecord
     self.table_name = 'users'
   end
 
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
   end
 
@@ -39,20 +41,20 @@ class MigratingSupporterRegistrationsToTicketUsers < ActiveRecord::Migration
     # Sum up if a user has bought more than one ticket
     TempSupporterRegistrations.all.each do |s|
       sup_reg = TempSupporterRegistrations.where(
-          ticket_id: s.ticket_id,
-          user_id: s.user_id,
-          conference_id: s.conference_id)
+        ticket_id: s.ticket_id,
+        user_id: s.user_id,
+        conference_id: s.conference_id
+      )
       quantity = sup_reg.count
 
-      if quantity > 1
-        # Save the amount in the first one
-        s.quantity = quantity
-        s.save
+      next unless quantity > 1
+      # Save the amount in the first one
+      s.quantity = quantity
+      s.save
 
-        # Delete the other
-        sup_reg = sup_reg.where('id not in (?)', [s.id])
-        sup_reg.destroy_all
-      end
+      # Delete the other
+      sup_reg = sup_reg.where('id not in (?)', [s.id])
+      sup_reg.destroy_all
     end
 
     remove_column :supporter_registrations, :registration_id
diff --git a/db/migrate/20140820123503_assign_users_to_events.rb b/db/migrate/20140820123503_assign_users_to_events.rb
index dc0334a7..4473c6e5 100644
--- a/db/migrate/20140820123503_assign_users_to_events.rb
+++ b/db/migrate/20140820123503_assign_users_to_events.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 class AssignUsersToEvents < ActiveRecord::Migration
-  class TempEvent < ActiveRecord::Base
+  class TempEvent < ApplicationRecord
     self.table_name = 'events'
   end
 
-  class TempUser < ActiveRecord::Base
+  class TempUser < ApplicationRecord
     self.table_name = 'users'
   end
 
-  class TempEventUser < ActiveRecord::Base
+  class TempEventUser < ApplicationRecord
     self.table_name = 'event_users'
     belongs_to :temp_event
     belongs_to :temp_user
@@ -37,6 +39,6 @@ class AssignUsersToEvents < ActiveRecord::Migration
   end
 
   def down
-    raise ActiveRecord::IrreversibleMigration.new('Cannot reverse migration.')
+    raise ActiveRecord::IrreversibleMigration, 'Cannot reverse migration.'
   end
 end
diff --git a/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb b/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
index 60b77df2..1f8733aa 100644
--- a/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
+++ b/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
@@ -1,35 +1,33 @@
+# frozen_string_literal: true
+
 class UndoWrongMigration20140801080705AddUsersToEvents < ActiveRecord::Migration
-  class TempEvent < ActiveRecord::Base
+  class TempEvent < ApplicationRecord
     self.table_name = 'events'
   end
 
-  class TempUser < ActiveRecord::Base
+  class TempUser < ApplicationRecord
     self.table_name = 'users'
   end
 
-  class TempEventUser < ActiveRecord::Base
+  class TempEventUser < ApplicationRecord
     self.table_name = 'event_users'
     belongs_to :temp_event
     belongs_to :temp_user
   end
 
-  class Version < ActiveRecord::Base
+  class Version < ApplicationRecord
     self.table_name = 'versions'
   end
 
   def up
-    if ActiveRecord::Migrator.get_all_versions.include? 20140801080705
+    if ActiveRecord::Migrator.get_all_versions.include? 20_140_801_080_705
       user_deleted = TempUser.find_by(email: 'deleted@localhost.osem')
 
       TempEvent.all.each do |event|
         whodunnit = Version.find_by(item_type: 'Event', item_id: event.id, event: 'create').whodunnit
         original_user = TempUser.find_by(id: whodunnit)
 
-        if original_user.blank?
-          original_submitter = user_deleted
-        else
-          original_submitter = original_user
-        end
+        original_submitter = original_user.presence || user_deleted
 
         # Substitute submitter record
         submitter = TempEventUser.find_by(event_id: event.id, event_role: 'submitter')
@@ -45,6 +43,6 @@ class UndoWrongMigration20140801080705AddUsersToEvents < ActiveRecord::Migration
   end
 
   def down
-    raise ActiveRecord::IrreversibleMigration.new('Cannot reverse migration.')
+    raise ActiveRecord::IrreversibleMigration, 'Cannot reverse migration.'
   end
 end
diff --git a/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb b/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
index 0dbf1045..4afa8603 100644
--- a/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
+++ b/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class SplitTicketPriceInPriceAndCurrency < ActiveRecord::Migration
-  class TempTicket < ActiveRecord::Base
+  class TempTicket < ApplicationRecord
     self.table_name = 'tickets'
   end
 
@@ -8,18 +10,17 @@ class SplitTicketPriceInPriceAndCurrency < ActiveRecord::Migration
 
     TempTicket.all.each do |ticket|
       # Replace currency symbol with ISO Code
-      if ticket.ticket_price
-        ticket.ticket_price.gsub!('€', 'EUR')
-        ticket.ticket_price.gsub!('$', 'USD')
-        ticket.ticket_price.gsub!('£', 'GBP')
-        ticket.ticket_price.gsub!('¥', 'CNY')
-        ticket.ticket_price.gsub!('₹', 'INR')
+      next unless ticket.ticket_price
+      ticket.ticket_price.gsub!('€', 'EUR')
+      ticket.ticket_price.gsub!('$', 'USD')
+      ticket.ticket_price.gsub!('£', 'GBP')
+      ticket.ticket_price.gsub!('¥', 'CNY')
+      ticket.ticket_price.gsub!('₹', 'INR')
 
-        money = ticket.ticket_price.to_money
-        ticket.price_cents = money.cents
-        ticket.price_currency = money.currency_as_string
-        ticket.save
-      end
+      money = ticket.ticket_price.to_money
+      ticket.price_cents = money.cents
+      ticket.price_currency = money.currency_as_string
+      ticket.save
     end
 
     remove_column :tickets, :ticket_price
diff --git a/db/migrate/20140825091222_create_splashpages.rb b/db/migrate/20140825091222_create_splashpages.rb
index 0c9ca9b6..4056d86c 100644
--- a/db/migrate/20140825091222_create_splashpages.rb
+++ b/db/migrate/20140825091222_create_splashpages.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSplashpages < ActiveRecord::Migration
   def change
     create_table :splashpages do |t|
diff --git a/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb b/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
index 222fa20b..c229934b 100644
--- a/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
+++ b/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
@@ -1,64 +1,64 @@
+# frozen_string_literal: true
+
 class MoveSplashpageAttributesFromConferenceToSplashpage < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempRegistrationPeriod < ActiveRecord::Base
+  class TempRegistrationPeriod < ApplicationRecord
     self.table_name = 'registration_periods'
   end
 
-  class TempContact < ActiveRecord::Base
+  class TempContact < ApplicationRecord
     self.table_name = 'contacts'
   end
 
-  class TempVenue < ActiveRecord::Base
+  class TempVenue < ApplicationRecord
     self.table_name = 'venues'
   end
 
-  class TempSplashpage < ActiveRecord::Base
+  class TempSplashpage < ApplicationRecord
     self.table_name = 'splashpages'
   end
 
   def change
     # Copy values to splashpage
     TempConference.all.each do |conference|
-      unless TempSplashpage.exists?(conference_id: conference.id)
-        splash = TempSplashpage.create(conference_id: conference.id,
-                                       public: conference.make_conference_public,
-                                       include_registrations: conference.include_registrations_in_splash,
-                                       include_tracks: conference.include_tracks_in_splash,
-                                       include_program: conference.include_program_in_splash,
-                                       include_banner: conference.include_banner_in_splash,
-                                       include_tickets: conference.include_tickets_in_splash,
-                                       ticket_description: conference.ticket_description,
-                                       include_sponsors: conference.include_sponsors_in_splash,
-                                       sponsor_description: conference.sponsor_description,
-                                       lodging_description: conference.lodging_description,
-                                       banner_description: conference.description,
-                                       banner_photo_file_name: conference.banner_photo_file_name,
-                                       banner_photo_content_type: conference.banner_photo_content_type,
-                                       banner_photo_file_size: conference.banner_photo_file_size,
-                                       banner_photo_updated_at: conference.banner_photo_updated_at)
+      next if TempSplashpage.exists?(conference_id: conference.id)
+      splash = TempSplashpage.create(conference_id: conference.id,
+                                     public: conference.make_conference_public,
+                                     include_registrations: conference.include_registrations_in_splash,
+                                     include_tracks: conference.include_tracks_in_splash,
+                                     include_program: conference.include_program_in_splash,
+                                     include_banner: conference.include_banner_in_splash,
+                                     include_tickets: conference.include_tickets_in_splash,
+                                     ticket_description: conference.ticket_description,
+                                     include_sponsors: conference.include_sponsors_in_splash,
+                                     sponsor_description: conference.sponsor_description,
+                                     lodging_description: conference.lodging_description,
+                                     banner_description: conference.description,
+                                     banner_photo_file_name: conference.banner_photo_file_name,
+                                     banner_photo_content_type: conference.banner_photo_content_type,
+                                     banner_photo_file_size: conference.banner_photo_file_size,
+                                     banner_photo_updated_at: conference.banner_photo_updated_at)
 
-        contact = TempContact.find_by(conference_id: conference.id)
-        if contact
-          splash.include_social_media = contact.public
-          splash.save
-        end
-
-        registration = TempRegistrationPeriod.find_by(conference_id: conference.id)
-        if registration
-          splash.registration_description = registration.description
-          splash.save
-        end
-
-        venue = TempVenue.find_by(id: conference.venue_id)
-        if venue
-          splash.include_lodgings = venue.include_lodgings_in_splash
-          splash.include_venue = venue.include_venue_in_splash
-          splash.save
-        end
+      contact = TempContact.find_by(conference_id: conference.id)
+      if contact
+        splash.include_social_media = contact.public
+        splash.save
       end
+
+      registration = TempRegistrationPeriod.find_by(conference_id: conference.id)
+      if registration
+        splash.registration_description = registration.description
+        splash.save
+      end
+
+      venue = TempVenue.find_by(id: conference.venue_id)
+      next unless venue
+      splash.include_lodgings = venue.include_lodgings_in_splash
+      splash.include_venue = venue.include_venue_in_splash
+      splash.save
     end
 
     # Remove columns
diff --git a/db/migrate/20140930092923_move_sponsor_email_to_contact.rb b/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
index 2fe5f47a..cff288d5 100644
--- a/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
+++ b/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class MoveSponsorEmailToContact < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempContact < ActiveRecord::Base
+  class TempContact < ApplicationRecord
     self.table_name = 'contacts'
   end
 
diff --git a/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb b/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
index ad2328c9..335db82e 100644
--- a/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
+++ b/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 class AddRequireHandicappedAccessToQuestions < ActiveRecord::Migration
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_registrations
     has_many :temp_questions
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -27,25 +29,25 @@ class AddRequireHandicappedAccessToQuestions < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
     belongs_to :temp_answer
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
diff --git a/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb b/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
index 0a63a380..2451fbcb 100644
--- a/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
+++ b/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 class AddAttendingWithPartnerToQuestions < ActiveRecord::Migration
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_registrations
     has_many :temp_questions
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -27,25 +29,25 @@ class AddAttendingWithPartnerToQuestions < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
     belongs_to :temp_answer
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
diff --git a/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb b/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
index fb0d8781..c4128a24 100644
--- a/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
+++ b/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 class AddStayingAtSuggestedHotelToQuestions < ActiveRecord::Migration
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_registrations
     has_many :temp_questions
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -27,25 +29,25 @@ class AddStayingAtSuggestedHotelToQuestions < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
     belongs_to :temp_answer
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
diff --git a/db/migrate/20141031225635_add_attending_social_events_to_questions.rb b/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
index 54e3bb33..e85f73b1 100644
--- a/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
+++ b/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 class AddAttendingSocialEventsToQuestions < ActiveRecord::Migration
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_registrations
     has_many :temp_questions
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -27,25 +29,25 @@ class AddAttendingSocialEventsToQuestions < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
     belongs_to :temp_answer
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
diff --git a/db/migrate/20141103132913_add_username_to_users.rb b/db/migrate/20141103132913_add_username_to_users.rb
index 59cd8591..48b0573c 100644
--- a/db/migrate/20141103132913_add_username_to_users.rb
+++ b/db/migrate/20141103132913_add_username_to_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddUsernameToUsers < ActiveRecord::Migration
   def change
     add_column :users, :username, :string
diff --git a/db/migrate/20141104131625_generate_username.rb b/db/migrate/20141104131625_generate_username.rb
index e1ddf111..0f1745de 100644
--- a/db/migrate/20141104131625_generate_username.rb
+++ b/db/migrate/20141104131625_generate_username.rb
@@ -1,15 +1,16 @@
+# frozen_string_literal: true
+
 class GenerateUsername < ActiveRecord::Migration
-  class TempUser < ActiveRecord::Base
+  class TempUser < ApplicationRecord
     self.table_name = 'users'
   end
 
   def change
     TempUser.all.each do |user|
-      if user.username.blank?
-        username = user.email.split('@')[0]
-        username += user.id.to_s if TempUser.find_by(username: username)
-        user.update_attributes(username: username)
-      end
+      next if user.username.present?
+      username = user.email.split('@')[0]
+      username += user.id.to_s if TempUser.find_by(username: username)
+      user.update(username: username)
     end
   end
 end
diff --git a/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb b/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
index 07830d74..6f3fa63c 100644
--- a/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
+++ b/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIsDisabledFlagToUser < ActiveRecord::Migration
   def change
     add_column :users, :is_disabled, :boolean, default: false
diff --git a/db/migrate/20141109172204_set_room_public_default_to_false.rb b/db/migrate/20141109172204_set_room_public_default_to_false.rb
index ae215bab..1b198154 100644
--- a/db/migrate/20141109172204_set_room_public_default_to_false.rb
+++ b/db/migrate/20141109172204_set_room_public_default_to_false.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SetRoomPublicDefaultToFalse < ActiveRecord::Migration
   def change
     change_column :rooms, :public, :boolean, default: false
diff --git a/db/migrate/20141113134103_add_position_to_sponsorship_level.rb b/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
index 5663d3e6..3683964d 100644
--- a/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
+++ b/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPositionToSponsorshipLevel < ActiveRecord::Migration
   def change
     add_column :sponsorship_levels, :position, :integer
diff --git a/db/migrate/20141117214230_move_banner_description_to_conference.rb b/db/migrate/20141117214230_move_banner_description_to_conference.rb
index 6073926f..ce3d7e8d 100644
--- a/db/migrate/20141117214230_move_banner_description_to_conference.rb
+++ b/db/migrate/20141117214230_move_banner_description_to_conference.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class MoveBannerDescriptionToConference < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempSplashpage < ActiveRecord::Base
+  class TempSplashpage < ApplicationRecord
     self.table_name = 'splashpages'
   end
 
@@ -15,7 +17,7 @@ class MoveBannerDescriptionToConference < ActiveRecord::Migration
     TempConference.all.each do |conference|
       if TempSplashpage.exists?(conference_id: conference.id)
         splash = TempSplashpage.find_by(conference_id: conference.id)
-        conference.update_attributes(description: splash.banner_description)
+        conference.update(description: splash.banner_description)
       end
     end
 
diff --git a/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb b/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
index 343ea467..e4701a12 100644
--- a/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
+++ b/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DropSplashDescriptionsAndPhoto < ActiveRecord::Migration
   def change
     remove_column :splashpages, :ticket_description
diff --git a/db/migrate/20141118143700_add_address_fields_to_venue.rb b/db/migrate/20141118143700_add_address_fields_to_venue.rb
index 01df5d9b..c91d6033 100644
--- a/db/migrate/20141118143700_add_address_fields_to_venue.rb
+++ b/db/migrate/20141118143700_add_address_fields_to_venue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddAddressFieldsToVenue < ActiveRecord::Migration
   def change
     add_column :venues, :street, :string
diff --git a/db/migrate/20141118150427_cleanup_venue.rb b/db/migrate/20141118150427_cleanup_venue.rb
index b985c676..31cb86fd 100644
--- a/db/migrate/20141118150427_cleanup_venue.rb
+++ b/db/migrate/20141118150427_cleanup_venue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CleanupVenue < ActiveRecord::Migration
   def change
     change_column :venues, :name, :string
diff --git a/db/migrate/20141118153918_change_venue_conference_association.rb b/db/migrate/20141118153918_change_venue_conference_association.rb
index 810179e5..773c254c 100644
--- a/db/migrate/20141118153918_change_venue_conference_association.rb
+++ b/db/migrate/20141118153918_change_venue_conference_association.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class ChangeVenueConferenceAssociation < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempVenue < ActiveRecord::Base
+  class TempVenue < ApplicationRecord
     self.table_name = 'venues'
   end
 
@@ -15,7 +17,7 @@ class ChangeVenueConferenceAssociation < ActiveRecord::Migration
     TempConference.all.each do |conference|
       if TempVenue.exists?(id: conference.venue_id)
         venue = TempVenue.find_by(id: conference.venue_id)
-        venue.update_attributes(conference_id: conference.id)
+        venue.update(conference_id: conference.id)
       end
     end
 
diff --git a/db/migrate/20141118162030_change_lodging_association_to_conference.rb b/db/migrate/20141118162030_change_lodging_association_to_conference.rb
index 352075ec..3e476d3e 100644
--- a/db/migrate/20141118162030_change_lodging_association_to_conference.rb
+++ b/db/migrate/20141118162030_change_lodging_association_to_conference.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 class ChangeLodgingAssociationToConference < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempVenue < ActiveRecord::Base
+  class TempVenue < ApplicationRecord
     self.table_name = 'venues'
   end
 
-  class TempLodging < ActiveRecord::Base
+  class TempLodging < ApplicationRecord
     self.table_name = 'lodgings'
   end
 
@@ -17,12 +19,11 @@ class ChangeLodgingAssociationToConference < ActiveRecord::Migration
 
     # Change association from venue and conference
     TempConference.all.each do |conference|
-      if TempVenue.exists?(conference_id: conference.id)
-        venue = TempVenue.find_by(conference_id: conference.id)
-        lodgings = TempLodging.where(venue_id: venue.id)
-        lodgings.each do |lodging|
-          lodging.update_attributes(conference_id: conference.id)
-        end
+      next unless TempVenue.exists?(conference_id: conference.id)
+      venue = TempVenue.find_by(conference_id: conference.id)
+      lodgings = TempLodging.where(venue_id: venue.id)
+      lodgings.each do |lodging|
+        lodging.update(conference_id: conference.id)
       end
     end
 
diff --git a/db/migrate/20141120205757_remove_public_from_room.rb b/db/migrate/20141120205757_remove_public_from_room.rb
index fa44e5ac..f96aa84c 100644
--- a/db/migrate/20141120205757_remove_public_from_room.rb
+++ b/db/migrate/20141120205757_remove_public_from_room.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemovePublicFromRoom < ActiveRecord::Migration
   def change
     remove_column :rooms, :public, :boolean, default: false
diff --git a/db/migrate/20141121102656_remove_description_from_call_for_paper.rb b/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
index 89e8cdbb..fc6282a5 100644
--- a/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
+++ b/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveDescriptionFromCallForPaper < ActiveRecord::Migration
   def change
     remove_column :call_for_papers, :description, :text
diff --git a/db/migrate/20141127161313_add_is_highlight_in_events.rb b/db/migrate/20141127161313_add_is_highlight_in_events.rb
index 0b61ef26..694e0ea2 100644
--- a/db/migrate/20141127161313_add_is_highlight_in_events.rb
+++ b/db/migrate/20141127161313_add_is_highlight_in_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIsHighlightInEvents < ActiveRecord::Migration
   def change
     add_column :events, :is_highlight, :boolean, default: false
diff --git a/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb b/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
index 2f794f75..9eb23d78 100644
--- a/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
+++ b/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 class MigrateDataRemoveColumnIncludeCfpInSplashAddColumnIncludeCfp < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempCallForPaper < ActiveRecord::Base
+  class TempCallForPaper < ApplicationRecord
     self.table_name = 'call_for_papers'
   end
 
-  class TempSplashpage < ActiveRecord::Base
+  class TempSplashpage < ApplicationRecord
     self.table_name = 'splashpages'
   end
 
@@ -17,11 +19,10 @@ class MigrateDataRemoveColumnIncludeCfpInSplashAddColumnIncludeCfp < ActiveRecor
     TempConference.all.each do |conference|
       cfp = TempCallForPaper.find_by(conference_id: conference.id)
 
-      if cfp && cfp.include_cfp_in_splash
-        splashpage = TempSplashpage.find_or_initialize_by(conference_id: conference.id)
-        splashpage.include_cfp = cfp.include_cfp_in_splash # true
-        splashpage.save!
-      end
+      next unless cfp&.include_cfp_in_splash
+      splashpage = TempSplashpage.find_or_initialize_by(conference_id: conference.id)
+      splashpage.include_cfp = cfp.include_cfp_in_splash # true
+      splashpage.save!
     end
 
     remove_column :call_for_papers, :include_cfp_in_splash, :boolean, default: false
diff --git a/db/migrate/20141130182139_drop_table_event_attachments.rb b/db/migrate/20141130182139_drop_table_event_attachments.rb
index 76f2d72e..dbe856c1 100644
--- a/db/migrate/20141130182139_drop_table_event_attachments.rb
+++ b/db/migrate/20141130182139_drop_table_event_attachments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DropTableEventAttachments < ActiveRecord::Migration
   def change
     drop_table :event_attachments
diff --git a/db/migrate/20150304135935_add_created_atto_qanswer.rb b/db/migrate/20150304135935_add_created_atto_qanswer.rb
index a0a2f4cf..e4a319e2 100644
--- a/db/migrate/20150304135935_add_created_atto_qanswer.rb
+++ b/db/migrate/20150304135935_add_created_atto_qanswer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCreatedAttoQanswer < ActiveRecord::Migration
   def change
     add_column :qanswers, :created_at, :datetime
diff --git a/db/migrate/20150415121038_add_description_to_event_type.rb b/db/migrate/20150415121038_add_description_to_event_type.rb
index fa688c02..3979d574 100644
--- a/db/migrate/20150415121038_add_description_to_event_type.rb
+++ b/db/migrate/20150415121038_add_description_to_event_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDescriptionToEventType < ActiveRecord::Migration
   def change
     add_column :event_types, :description, :string
diff --git a/db/migrate/20150417050953_add_url_to_commercial.rb b/db/migrate/20150417050953_add_url_to_commercial.rb
index 56adf34f..46bf73fb 100644
--- a/db/migrate/20150417050953_add_url_to_commercial.rb
+++ b/db/migrate/20150417050953_add_url_to_commercial.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddUrlToCommercial < ActiveRecord::Migration
-  class TempCommercial < ActiveRecord::Base
+  class TempCommercial < ApplicationRecord
     self.table_name = 'commercials'
   end
 
diff --git a/db/migrate/20150929142405_change_postalcode_format_in_venues.rb b/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
index 010f9349..93fdf50f 100644
--- a/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
+++ b/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class ChangePostalcodeFormatInVenues < ActiveRecord::Migration
   def up
     change_column :venues, :postalcode, :string
   end
 
   def down
-    raise ActiveRecord::IrreversibleMigration.new('Cannot reverse migration.')
+    raise ActiveRecord::IrreversibleMigration, 'Cannot reverse migration.'
   end
 end
diff --git a/db/migrate/20151005161518_rename_templates_in_email_settings.rb b/db/migrate/20151005161518_rename_templates_in_email_settings.rb
index 8cb3ad49..848cd9a3 100644
--- a/db/migrate/20151005161518_rename_templates_in_email_settings.rb
+++ b/db/migrate/20151005161518_rename_templates_in_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameTemplatesInEmailSettings < ActiveRecord::Migration
   def change
     rename_column :email_settings, :registration_email_template, :registration_body
diff --git a/db/migrate/20151018152439_create_programs_table.rb b/db/migrate/20151018152439_create_programs_table.rb
index 4a71edb4..5f61292b 100644
--- a/db/migrate/20151018152439_create_programs_table.rb
+++ b/db/migrate/20151018152439_create_programs_table.rb
@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 class CreateProgramsTable < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempCfp < ActiveRecord::Base
+  class TempCfp < ApplicationRecord
     self.table_name = 'cfps'
   end
 
-  class TempCallForPaper < ActiveRecord::Base
+  class TempCallForPaper < ApplicationRecord
     self.table_name = 'call_for_papers'
   end
 
-  class TempProgram < ActiveRecord::Base
+  class TempProgram < ApplicationRecord
     self.table_name = 'programs'
   end
 
@@ -27,21 +29,19 @@ class CreateProgramsTable < ActiveRecord::Migration
     add_column :call_for_papers, :program_id, :integer
 
     TempConference.all.each do |conference|
-      unless TempProgram.find_by(conference_id: conference.id)
-        program = TempProgram.new
-        program.conference_id = conference.id
-        program.save!
+      next if TempProgram.find_by(conference_id: conference.id)
+      program = TempProgram.new
+      program.conference_id = conference.id
+      program.save!
 
-        if (cfp = TempCallForPaper.find_by(conference_id: conference.id))
-          cfp.program_id = program.id
-          cfp.save!
+      next unless (cfp = TempCallForPaper.find_by(conference_id: conference.id))
+      cfp.program_id = program.id
+      cfp.save!
 
-          program.rating = cfp.rating
-          program.schedule_public = cfp.schedule_public
-          program.schedule_fluid = cfp.schedule_changes
-          program.save!
-        end
-      end
+      program.rating = cfp.rating
+      program.schedule_public = cfp.schedule_public
+      program.schedule_fluid = cfp.schedule_changes
+      program.save!
     end
     remove_column :call_for_papers, :conference_id
     remove_column :call_for_papers, :rating
@@ -58,16 +58,14 @@ class CreateProgramsTable < ActiveRecord::Migration
     add_column :call_for_papers, :schedule_changes, :boolean, default: false
 
     TempConference.all.each do |conference|
-      if (program = TempProgram.find_by(conference_id: conference.id))
-        if (cfp = TempCallForPaper.find_by(program_id: program.id))
-          cfp.conference_id = program.conference_id
-          cfp.rating = program.rating
-          cfp.schedule_public = program.schedule_public
-          cfp.schedule_changes = program.schedule_fluid
+      next unless (program = TempProgram.find_by(conference_id: conference.id))
+      next unless (cfp = TempCallForPaper.find_by(program_id: program.id))
+      cfp.conference_id = program.conference_id
+      cfp.rating = program.rating
+      cfp.schedule_public = program.schedule_public
+      cfp.schedule_changes = program.schedule_fluid
 
-          cfp.save!
-        end
-      end
+      cfp.save!
     end
 
     remove_column :call_for_papers, :program_id
diff --git a/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb b/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
index b540b9a3..37190852 100644
--- a/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
+++ b/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
@@ -1,25 +1,27 @@
+# frozen_string_literal: true
+
 class RenameConferenceIdToProgramIdInEventsTracksDifficultyLevels < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempEvent < ActiveRecord::Base
+  class TempEvent < ApplicationRecord
     self.table_name = 'events'
   end
 
-  class TempEventType < ActiveRecord::Base
+  class TempEventType < ApplicationRecord
     self.table_name = 'event_types'
   end
 
-  class TempTrack < ActiveRecord::Base
+  class TempTrack < ApplicationRecord
     self.table_name = 'tracks'
   end
 
-  class TempDifficultyLevel < ActiveRecord::Base
+  class TempDifficultyLevel < ApplicationRecord
     self.table_name = 'difficulty_levels'
   end
 
-  class TempProgram < ActiveRecord::Base
+  class TempProgram < ApplicationRecord
     self.table_name = 'programs'
   end
 
@@ -68,26 +70,25 @@ class RenameConferenceIdToProgramIdInEventsTracksDifficultyLevels < ActiveRecord
     TempConference.all.each do |conference|
       program = TempProgram.find_by(conference_id: conference.id)
 
-      if program
-        TempEvent.where(program_id: program.id).each do |event|
-          event.conference_id = conference.id
-          event.save!
-        end
+      next unless program
+      TempEvent.where(program_id: program.id).each do |event|
+        event.conference_id = conference.id
+        event.save!
+      end
 
-        TempEventType.where(program_id: program.id).each do |event_type|
-          event_type.conference_id = conference.id
-          event_type.save!
-        end
+      TempEventType.where(program_id: program.id).each do |event_type|
+        event_type.conference_id = conference.id
+        event_type.save!
+      end
 
-        TempTrack.where(program_id: program.id).each do |track|
-          track.conference_id = conference.id
-          track.save!
-        end
+      TempTrack.where(program_id: program.id).each do |track|
+        track.conference_id = conference.id
+        track.save!
+      end
 
-        TempDifficultyLevel.where(program_id: program.id).each do |difficulty_level|
-          difficulty_level.conference_id = conference.id
-          difficulty_level.save!
-        end
+      TempDifficultyLevel.where(program_id: program.id).each do |difficulty_level|
+        difficulty_level.conference_id = conference.id
+        difficulty_level.save!
       end
     end
 
diff --git a/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb b/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
index ca2978ca..b43c6c23 100644
--- a/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
+++ b/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameEmailSettingsWithCfpAndProgram < ActiveRecord::Migration
   def change
     rename_column :email_settings, :send_on_call_for_papers_schedule_public, :send_on_program_schedule_public
diff --git a/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb b/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
index ca8ef153..b2f28567 100644
--- a/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
+++ b/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
@@ -1,18 +1,20 @@
+# frozen_string_literal: true
+
 class ChangeConferenceIdToVenueIdInRooms < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_one :temp_venue
   end
 
-  class TempVenue < ActiveRecord::Base
+  class TempVenue < ApplicationRecord
     self.table_name = 'venues'
 
     belongs_to :temp_conference
     has_many :temp_rooms
   end
 
-  class TempRoom < ActiveRecord::Base
+  class TempRoom < ApplicationRecord
     self.table_name = 'rooms'
 
     belongs_to :temp_venue
@@ -43,9 +45,7 @@ class ChangeConferenceIdToVenueIdInRooms < ActiveRecord::Migration
       venue = TempVenue.find(room.venue_id)
       conference = TempConference.find(venue.conference_id)
 
-      if conference
-        room.conference_id = conference.id
-      end
+      room.conference_id = conference.id if conference
 
       room.save!
     end
diff --git a/db/migrate/20160201221411_add_registration_limit_to_conferences.rb b/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
index bbc8724e..82aa4df7 100644
--- a/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
+++ b/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRegistrationLimitToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :registration_limit, :integer, default: 0
diff --git a/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb b/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
index 6f8424b8..ca8af270 100644
--- a/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
+++ b/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RenameRolesUsersToUsersRoles < ActiveRecord::Migration
   def change
     rename_table :roles_users, :users_roles
diff --git a/db/migrate/20160309182642_remove_social_events_table.rb b/db/migrate/20160309182642_remove_social_events_table.rb
index e44a7c3f..740203f1 100644
--- a/db/migrate/20160309182642_remove_social_events_table.rb
+++ b/db/migrate/20160309182642_remove_social_events_table.rb
@@ -1,18 +1,20 @@
+# frozen_string_literal: true
+
 class RemoveSocialEventsTable < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_social_events
   end
 
-  class TempSocialEvent < ActiveRecord::Base
+  class TempSocialEvent < ApplicationRecord
     self.table_name = 'social_events'
 
     belongs_to :temp_conference
     has_and_belongs_to_many :temp_registrations
   end
 
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
@@ -20,20 +22,20 @@ class RemoveSocialEventsTable < ActiveRecord::Migration
     has_and_belongs_to_many :temp_qanswers
   end
 
-  class TempRegistrationsSocialEvent < ActiveRecord::Base
+  class TempRegistrationsSocialEvent < ApplicationRecord
     self.table_name = 'registrations_social_events'
 
     belongs_to :temp_registrations
     belongs_to :temp_social_events
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -42,14 +44,14 @@ class RemoveSocialEventsTable < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
@@ -57,11 +59,11 @@ class RemoveSocialEventsTable < ActiveRecord::Migration
     has_and_belongs_to_many :temp_registrations
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
@@ -116,17 +118,16 @@ class RemoveSocialEventsTable < ActiveRecord::Migration
     qtype = TempQuestionType.find_by(title: 'Multiple Choice')
 
     TempConference.all.each do |conference|
-      if qtype && (question = TempQuestion.find_by(title: 'Which of the following social events are you going to attend?',
-                                                   conference_id: conference.id, question_type_id: qtype.id))
-        TempQanswer.where(question_id: question.id).each do |qa|
-          TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
-            answer = TempAnswer.find(qa.answer_id)
-            registration = TempRegistration.find(qa_registration.registration_id)
-            social_event = TempSocialEvent.find_or_create_by!(title: answer.title,
-                                                              conference_id: conference.id)
-            TempRegistrationsSocialEvent.find_or_create_by!(registration_id: registration.id,
-                                                            social_event_id: social_event.id)
-          end
+      next unless qtype && (question = TempQuestion.find_by(title: 'Which of the following social events are you going to attend?',
+                                                            conference_id: conference.id, question_type_id: qtype.id))
+      TempQanswer.where(question_id: question.id).each do |qa|
+        TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
+          answer = TempAnswer.find(qa.answer_id)
+          registration = TempRegistration.find(qa_registration.registration_id)
+          social_event = TempSocialEvent.find_or_create_by!(title: answer.title,
+                                                            conference_id: conference.id)
+          TempRegistrationsSocialEvent.find_or_create_by!(registration_id: registration.id,
+                                                          social_event_id: social_event.id)
         end
       end
     end
diff --git a/db/migrate/20160309182655_remove_dietary_choices_table.rb b/db/migrate/20160309182655_remove_dietary_choices_table.rb
index c61876bc..78f9580f 100644
--- a/db/migrate/20160309182655_remove_dietary_choices_table.rb
+++ b/db/migrate/20160309182655_remove_dietary_choices_table.rb
@@ -1,29 +1,31 @@
+# frozen_string_literal: true
+
 class RemoveDietaryChoicesTable < ActiveRecord::Migration
-  class TempDietaryChoice < ActiveRecord::Base
+  class TempDietaryChoice < ApplicationRecord
     self.table_name = 'dietary_choices'
 
     belongs_to :temp_conference
   end
 
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
 
     has_many :temp_dietary_choices, dependent: :destroy
   end
 
-  class TempRegistration < ActiveRecord::Base
+  class TempRegistration < ApplicationRecord
     self.table_name = 'registrations'
 
     belongs_to :temp_conference
   end
 
-  class TempQuestionType < ActiveRecord::Base
+  class TempQuestionType < ApplicationRecord
     self.table_name = 'question_types'
 
     has_many :temp_questions
   end
 
-  class TempQuestion < ActiveRecord::Base
+  class TempQuestion < ApplicationRecord
     self.table_name = 'questions'
 
     has_many :temp_qanswers
@@ -32,14 +34,14 @@ class RemoveDietaryChoicesTable < ActiveRecord::Migration
     has_and_belongs_to_many :temp_conferences
   end
 
-  class TempAnswer < ActiveRecord::Base
+  class TempAnswer < ApplicationRecord
     self.table_name = 'answers'
 
     has_many :temp_qanswers
     has_many :temp_questions, through: :temp_qanswers
   end
 
-  class TempQanswer < ActiveRecord::Base
+  class TempQanswer < ApplicationRecord
     self.table_name = 'qanswers'
 
     belongs_to :temp_question
@@ -47,78 +49,74 @@ class RemoveDietaryChoicesTable < ActiveRecord::Migration
     has_and_belongs_to_many :temp_registrations
   end
 
-  class TempConferencesQuestions < ActiveRecord::Base
+  class TempConferencesQuestions < ApplicationRecord
     self.table_name = 'conferences_questions'
   end
 
-  class TempQanswerRegistration < ActiveRecord::Base
+  class TempQanswerRegistration < ApplicationRecord
     self.table_name = 'qanswers_registrations'
   end
 
   def up
     # Create Question of 'Multiple Choice' type
-    if TempDietaryChoice.all.any?
-      qtype = TempQuestionType.find_or_create_by!(title: 'Single Choice')
-    end
+    qtype = TempQuestionType.find_or_create_by!(title: 'Single Choice') if TempDietaryChoice.all.any?
 
     # Migrate dietary_choice_id to a question
     TempConference.all.each do |conference|
-      if TempDietaryChoice.where(conference_id: conference.id).any?
-        # Find existing question or initialize it
-        question = TempQuestion.find_or_initialize_by(title: 'Which is your dietary choice?',
-                                                      conference_id: conference.id,
-                                                      question_type_id: qtype.id)
-        question.save!
-        # Enable the question for the conference
-        TempConferencesQuestions.find_or_create_by!(conference_id: conference.id,
-                                                    question_id: question.id)
+      next unless TempDietaryChoice.where(conference_id: conference.id).any?
+      # Find existing question or initialize it
+      question = TempQuestion.find_or_initialize_by(title: 'Which is your dietary choice?',
+                                                    conference_id: conference.id,
+                                                    question_type_id: qtype.id)
+      question.save!
+      # Enable the question for the conference
+      TempConferencesQuestions.find_or_create_by!(conference_id: conference.id,
+                                                  question_id: question.id)
 
-        TempDietaryChoice.where(conference_id: conference.id).each do |dietary_choice|
-          answer = TempAnswer.find_or_create_by!(title: dietary_choice.title)
-          # Associate answer with the question
-          qa = TempQanswer.find_or_initialize_by(question_id: question.id,
-                                                 answer_id: answer.id)
-          qa.save!
+      TempDietaryChoice.where(conference_id: conference.id).each do |dietary_choice|
+        answer = TempAnswer.find_or_create_by!(title: dietary_choice.title)
+        # Associate answer with the question
+        qa = TempQanswer.find_or_initialize_by(question_id: question.id,
+                                               answer_id: answer.id)
+        qa.save!
 
-          # Associate appropriate answer with registration
-          TempRegistration.where(dietary_choice_id: dietary_choice.id).each do |registration|
-            TempQanswerRegistration.find_or_create_by!(registration_id: registration.id,
-                                                       qanswer_id: qa.id)
-          end
+        # Associate appropriate answer with registration
+        TempRegistration.where(dietary_choice_id: dietary_choice.id).each do |registration|
+          TempQanswerRegistration.find_or_create_by!(registration_id: registration.id,
+                                                     qanswer_id: qa.id)
         end
       end
     end
 
     # Migrate other_dietary_choice to a question and put data in other_special_needs
     TempRegistration.all.each do |registration|
-      if registration.other_dietary_choice.present?
-        conference = TempConference.find(registration.conference_id)
-        qtype = TempQuestionType.find_or_create_by!(title: 'Yes/No')
-        question = TempQuestion.find_or_initialize_by(title: 'Do you have another dietary choice?',
-                                                      conference_id: conference.id,
-                                                      question_type_id: qtype.id)
-        question.save!
-        # Enable the question for the conference
-        TempConferencesQuestions.find_or_create_by!(conference_id: conference.id,
-                                                    question_id: question.id)
+      next if registration.other_dietary_choice.blank?
+      conference = TempConference.find(registration.conference_id)
+      qtype = TempQuestionType.find_or_create_by!(title: 'Yes/No')
+      question = TempQuestion.find_or_initialize_by(title: 'Do you have another dietary choice?',
+                                                    conference_id: conference.id,
+                                                    question_type_id: qtype.id)
+      question.save!
+      # Enable the question for the conference
+      TempConferencesQuestions.find_or_create_by!(conference_id: conference.id,
+                                                  question_id: question.id)
 
-        # Create 'Yes' answer
-        answer_yes = TempAnswer.find_or_create_by!(title: 'Yes')
+      # Create 'Yes' answer
+      answer_yes = TempAnswer.find_or_create_by!(title: 'Yes')
 
-        # Associate answer with the question
-        qa = TempQanswer.find_or_initialize_by(question_id: question.id,
-                                               answer_id: answer_yes.id)
+      # Associate answer with the question
+      qa = TempQanswer.find_or_initialize_by(question_id: question.id,
+                                             answer_id: answer_yes.id)
 
-        qa.save!
+      qa.save!
 
-        # Associate appropriate answer with registration
-        TempQanswerRegistration.find_or_create_by!(registration_id: registration.id,
-                                                   qanswer_id: qa.id)
+      # Associate appropriate answer with registration
+      TempQanswerRegistration.find_or_create_by!(registration_id: registration.id,
+                                                 qanswer_id: qa.id)
 
-        # Move data from other_dietary_choice to other_special_needs
-        registration.other_special_needs << "Other dietary choice: #{registration.other_dietary_choice}."
-        registration.save!
-      end
+      # Move data from other_dietary_choice to other_special_needs
+      registration.other_special_needs << "Other dietary choice: #{registration.other_dietary_choice}."
+      registration.save!
     end
 
     remove_column :conferences, :use_dietary_choices
@@ -140,17 +138,16 @@ class RemoveDietaryChoicesTable < ActiveRecord::Migration
 
     qtype = TempQuestionType.find_by(title: 'Single Choice')
     TempConference.all.each do |conference|
-      if qtype && (question = TempQuestion.find_by(title: 'Which is your dietary choice?',
-                                                   conference_id: conference.id, question_type_id: qtype.id))
-        TempQanswer.where(question_id: question.id).each do |qa|
-          TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
-            answer = TempAnswer.find(qa.answer_id)
-            registration = TempRegistration.find(qa_registration.registration_id)
-            dietary_choice = TempDietaryChoice.find_or_create_by!(title: answer.title,
-                                                                  conference_id: conference.id)
-            registration.dietary_choice_id = dietary_choice.id
-            registration.save!
-          end
+      next unless qtype && (question = TempQuestion.find_by(title: 'Which is your dietary choice?',
+                                                            conference_id: conference.id, question_type_id: qtype.id))
+      TempQanswer.where(question_id: question.id).each do |qa|
+        TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
+          answer = TempAnswer.find(qa.answer_id)
+          registration = TempRegistration.find(qa_registration.registration_id)
+          dietary_choice = TempDietaryChoice.find_or_create_by!(title: answer.title,
+                                                                conference_id: conference.id)
+          registration.dietary_choice_id = dietary_choice.id
+          registration.save!
         end
       end
     end
@@ -158,14 +155,13 @@ class RemoveDietaryChoicesTable < ActiveRecord::Migration
     qtype = TempQuestionType.find_by(title: 'Yes/No')
     answer_yes = TempAnswer.find_by(title: 'Yes')
     TempConference.all.each do |conference|
-      if qtype && (question = TempQuestion.find_by(title: 'Do you have another dietary choice?',
-                                                   conference_id: conference.id, question_type_id: qtype.id))
-        TempQanswer.where(question_id: question.id, answer_id: answer_yes.id).each do |qa|
-          TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
-            registration = TempRegistration.find(qa_registration.registration_id)
-            registration.other_dietary_choice = 'Yes'
-            registration.save!
-          end
+      next unless qtype && (question = TempQuestion.find_by(title: 'Do you have another dietary choice?',
+                                                            conference_id: conference.id, question_type_id: qtype.id))
+      TempQanswer.where(question_id: question.id, answer_id: answer_yes.id).each do |qa|
+        TempQanswerRegistration.where(qanswer_id: qa.id).each do |qa_registration|
+          registration = TempRegistration.find(qa_registration.registration_id)
+          registration.other_dietary_choice = 'Yes'
+          registration.save!
         end
       end
     end
diff --git a/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb b/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
index f1d3171e..01fbd3a7 100644
--- a/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
+++ b/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveHtmlExportPathFromConferences < ActiveRecord::Migration
   def change
     remove_column :conferences, :html_export_path, :string
diff --git a/db/migrate/20160320220630_add_languages_to_program.rb b/db/migrate/20160320220630_add_languages_to_program.rb
index b49c01d1..49be193f 100644
--- a/db/migrate/20160320220630_add_languages_to_program.rb
+++ b/db/migrate/20160320220630_add_languages_to_program.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddLanguagesToProgram < ActiveRecord::Migration
   def change
     add_column :programs, :languages, :string
diff --git a/db/migrate/20160323154504_add_max_attendees_to_events.rb b/db/migrate/20160323154504_add_max_attendees_to_events.rb
index a5a0d415..bb3e770f 100644
--- a/db/migrate/20160323154504_add_max_attendees_to_events.rb
+++ b/db/migrate/20160323154504_add_max_attendees_to_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMaxAttendeesToEvents < ActiveRecord::Migration
   def change
     add_column :events, :max_attendees, :integer
diff --git a/db/migrate/20160326075326_add_attended_to_events_registrations.rb b/db/migrate/20160326075326_add_attended_to_events_registrations.rb
index 2cbb6edc..562cdf34 100644
--- a/db/migrate/20160326075326_add_attended_to_events_registrations.rb
+++ b/db/migrate/20160326075326_add_attended_to_events_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddAttendedToEventsRegistrations < ActiveRecord::Migration
   def change
     add_column :events_registrations, :attended, :boolean, default: false, null: false
diff --git a/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb b/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
index 903ec851..6e1e7200 100644
--- a/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
+++ b/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIdAndCreatedAtToEventsRegistrations < ActiveRecord::Migration
   def change
     add_column :events_registrations, :id, :primary_key
diff --git a/db/migrate/20160427101444_remove_photos.rb b/db/migrate/20160427101444_remove_photos.rb
index 966cf187..d1f93a63 100644
--- a/db/migrate/20160427101444_remove_photos.rb
+++ b/db/migrate/20160427101444_remove_photos.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemovePhotos < ActiveRecord::Migration
   def change
     drop_table :photos do |t|
diff --git a/db/migrate/20160427104236_add_pictures.rb b/db/migrate/20160427104236_add_pictures.rb
index 5a56da9c..dcfa6a23 100644
--- a/db/migrate/20160427104236_add_pictures.rb
+++ b/db/migrate/20160427104236_add_pictures.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPictures < ActiveRecord::Migration
   def change
     add_column :conferences, :picture, :string
diff --git a/db/migrate/20160427104237_add_blind_voting_to_programs.rb b/db/migrate/20160427104237_add_blind_voting_to_programs.rb
index 0313cf19..f92be56d 100644
--- a/db/migrate/20160427104237_add_blind_voting_to_programs.rb
+++ b/db/migrate/20160427104237_add_blind_voting_to_programs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddBlindVotingToPrograms < ActiveRecord::Migration
   def change
     add_column :programs, :blind_voting, :boolean, default: false
diff --git a/db/migrate/20160427104238_add_voting_dates_to_program.rb b/db/migrate/20160427104238_add_voting_dates_to_program.rb
index 9dcbf752..32c20714 100644
--- a/db/migrate/20160427104238_add_voting_dates_to_program.rb
+++ b/db/migrate/20160427104238_add_voting_dates_to_program.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddVotingDatesToProgram < ActiveRecord::Migration
   def change
     add_column :programs, :voting_start_date, :datetime
diff --git a/db/migrate/20160524050538_add_conference_id_to_versions.rb b/db/migrate/20160524050538_add_conference_id_to_versions.rb
index 345218f1..e6c8a411 100644
--- a/db/migrate/20160524050538_add_conference_id_to_versions.rb
+++ b/db/migrate/20160524050538_add_conference_id_to_versions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddConferenceIdToVersions < ActiveRecord::Migration
   def change
     add_column :versions, :conference_id, :integer
diff --git a/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb b/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
index 77607c3f..fb3cedf6 100644
--- a/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
+++ b/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveUnusedLogoColumnsAndUseDifficultyLevelsFromConferences < ActiveRecord::Migration
   def up
     remove_column :conferences, :logo_updated_at
diff --git a/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb b/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
index a1f0f4d5..1770d353 100644
--- a/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
+++ b/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveUnusedLogoColumnsFromSponsors < ActiveRecord::Migration
   def up
     remove_column :sponsors, :logo_updated_at
diff --git a/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb b/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
index f70926df..eccfffb2 100644
--- a/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
+++ b/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveLogoAndProgressAndTimeSlotsFromEvents < ActiveRecord::Migration
   def up
     remove_column :events, :logo_file_name
diff --git a/db/migrate/20160606040848_create_payments.rb b/db/migrate/20160606040848_create_payments.rb
index 6792ad02..6db6f4c2 100644
--- a/db/migrate/20160606040848_create_payments.rb
+++ b/db/migrate/20160606040848_create_payments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreatePayments < ActiveRecord::Migration
   def change
     create_table :payments do |t|
diff --git a/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb b/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
index 133a047b..3c3f5997 100644
--- a/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
+++ b/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddPaymentIdToTicketPurchases < ActiveRecord::Migration
   def change
     add_column :ticket_purchases, :payment_id, :integer
diff --git a/db/migrate/20160614145614_add_id_to_users_roles.rb b/db/migrate/20160614145614_add_id_to_users_roles.rb
index 20153f96..59b8936a 100644
--- a/db/migrate/20160614145614_add_id_to_users_roles.rb
+++ b/db/migrate/20160614145614_add_id_to_users_roles.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIdToUsersRoles < ActiveRecord::Migration
   def change
     add_column :users_roles, :id, :primary_key
diff --git a/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb b/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
index 78d61171..c0e29eb1 100644
--- a/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
+++ b/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveUnusedPhotoColumnsFromVenues < ActiveRecord::Migration
   def up
     remove_column :venues, :photo_updated_at
diff --git a/db/migrate/20160704091928_create_schedules.rb b/db/migrate/20160704091928_create_schedules.rb
index 19370ab4..184046cc 100644
--- a/db/migrate/20160704091928_create_schedules.rb
+++ b/db/migrate/20160704091928_create_schedules.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateSchedules < ActiveRecord::Migration
   def change
     create_table :schedules do |t|
diff --git a/db/migrate/20160704092023_create_event_schedules.rb b/db/migrate/20160704092023_create_event_schedules.rb
index 3762f7e2..8158b277 100644
--- a/db/migrate/20160704092023_create_event_schedules.rb
+++ b/db/migrate/20160704092023_create_event_schedules.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateEventSchedules < ActiveRecord::Migration
   def change
     create_table :event_schedules do |t|
diff --git a/db/migrate/20160815094215_add_times_to_conferences.rb b/db/migrate/20160815094215_add_times_to_conferences.rb
index 758ed841..70630f01 100644
--- a/db/migrate/20160815094215_add_times_to_conferences.rb
+++ b/db/migrate/20160815094215_add_times_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTimesToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :start_hour, :integer, default: 9
diff --git a/db/migrate/20160815140302_add_index_to_event_schedule.rb b/db/migrate/20160815140302_add_index_to_event_schedule.rb
index 51ee51d4..01dc017b 100644
--- a/db/migrate/20160815140302_add_index_to_event_schedule.rb
+++ b/db/migrate/20160815140302_add_index_to_event_schedule.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddIndexToEventSchedule < ActiveRecord::Migration
   def change
-    add_index :event_schedules, [:event_id, :schedule_id], unique: true
+    add_index :event_schedules, %i[event_id schedule_id], unique: true
   end
 end
diff --git a/db/migrate/20161229080315_add_comments_count_to_events.rb b/db/migrate/20161229080315_add_comments_count_to_events.rb
index e1d6ebec..25e9ed58 100644
--- a/db/migrate/20161229080315_add_comments_count_to_events.rb
+++ b/db/migrate/20161229080315_add_comments_count_to_events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCommentsCountToEvents < ActiveRecord::Migration
   def change
     add_column :events, :comments_count, :integer, default: 0, null: false
diff --git a/db/migrate/20170108053041_add_default_to_revision_in_conference.rb b/db/migrate/20170108053041_add_default_to_revision_in_conference.rb
index 1c3571de..1e06838c 100644
--- a/db/migrate/20170108053041_add_default_to_revision_in_conference.rb
+++ b/db/migrate/20170108053041_add_default_to_revision_in_conference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDefaultToRevisionInConference < ActiveRecord::Migration
   def change
     change_column :conferences, :revision, :integer, default: 0, null: false
diff --git a/db/migrate/20170129075434_create_resources_table.rb b/db/migrate/20170129075434_create_resources_table.rb
index 8228ddda..b3aec9df 100644
--- a/db/migrate/20170129075434_create_resources_table.rb
+++ b/db/migrate/20170129075434_create_resources_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateResourcesTable < ActiveRecord::Migration
   def change
     create_table :resources do |t|
diff --git a/db/migrate/20170212145523_add_enabled_to_event_schedules.rb b/db/migrate/20170212145523_add_enabled_to_event_schedules.rb
index d89505fe..9d9cb819 100644
--- a/db/migrate/20170212145523_add_enabled_to_event_schedules.rb
+++ b/db/migrate/20170212145523_add_enabled_to_event_schedules.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddEnabledToEventSchedules < ActiveRecord::Migration
   def change
     add_column :event_schedules, :enabled, :boolean, default: true
diff --git a/db/migrate/20170213145807_change_email_public_from_users.rb b/db/migrate/20170213145807_change_email_public_from_users.rb
index 2bbaffa6..adac2310 100644
--- a/db/migrate/20170213145807_change_email_public_from_users.rb
+++ b/db/migrate/20170213145807_change_email_public_from_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeEmailPublicFromUsers < ActiveRecord::Migration
   def up
     change_column_default :users, :email_public, true
diff --git a/db/migrate/20170302145716_add_schedule_interval_to_programs.rb b/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
index 617aaf1e..1cc8bdcc 100644
--- a/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
+++ b/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddScheduleIntervalToPrograms < ActiveRecord::Migration
   def change
     add_column :programs, :schedule_interval, :integer, default: 15, null: false
diff --git a/db/migrate/20170419132148_add_week_to_ticket_purchases.rb b/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
index 0862eb16..1bdfe14e 100644
--- a/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
+++ b/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddWeekToTicketPurchases < ActiveRecord::Migration
-  class TmpTicketPurchase < ActiveRecord::Base
+  class TmpTicketPurchase < ApplicationRecord
     self.table_name = 'ticket_purchases'
   end
 
diff --git a/db/migrate/20170516190048_create_booths.rb b/db/migrate/20170516190048_create_booths.rb
index d2aa0be6..4c315511 100644
--- a/db/migrate/20170516190048_create_booths.rb
+++ b/db/migrate/20170516190048_create_booths.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateBooths < ActiveRecord::Migration
   def change
     create_table :booths do |t|
diff --git a/db/migrate/20170529215453_create_organizations.rb b/db/migrate/20170529215453_create_organizations.rb
index 0fa5450b..ffa424cc 100644
--- a/db/migrate/20170529215453_create_organizations.rb
+++ b/db/migrate/20170529215453_create_organizations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateOrganizations < ActiveRecord::Migration
   def change
     create_table :organizations do |t|
diff --git a/db/migrate/20170530072155_add_type_to_cfps.rb b/db/migrate/20170530072155_add_type_to_cfps.rb
index 50423281..9a5ccf6a 100644
--- a/db/migrate/20170530072155_add_type_to_cfps.rb
+++ b/db/migrate/20170530072155_add_type_to_cfps.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class AddTypeToCfps < ActiveRecord::Migration
-  class TmpCfp < ActiveRecord::Base
+  class TmpCfp < ApplicationRecord
     self.table_name = 'cfps'
   end
 
diff --git a/db/migrate/20170530112510_create_booth_requests.rb b/db/migrate/20170530112510_create_booth_requests.rb
index 75e73a93..a6358a68 100644
--- a/db/migrate/20170530112510_create_booth_requests.rb
+++ b/db/migrate/20170530112510_create_booth_requests.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateBoothRequests < ActiveRecord::Migration
   def change
     create_table :booth_requests do |t|
diff --git a/db/migrate/20170531094819_move_conferences_to_organizations.rb b/db/migrate/20170531094819_move_conferences_to_organizations.rb
index e70acf16..6cd3fdee 100644
--- a/db/migrate/20170531094819_move_conferences_to_organizations.rb
+++ b/db/migrate/20170531094819_move_conferences_to_organizations.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class MoveConferencesToOrganizations < ActiveRecord::Migration
-  class TempConference < ActiveRecord::Base
+  class TempConference < ApplicationRecord
     self.table_name = 'conferences'
   end
 
-  class TempOrganization < ActiveRecord::Base
+  class TempOrganization < ApplicationRecord
     self.table_name = 'organizations'
   end
 
diff --git a/db/migrate/20170603095900_create_physical_tickets.rb b/db/migrate/20170603095900_create_physical_tickets.rb
index 5e0c1d98..ef8abb65 100644
--- a/db/migrate/20170603095900_create_physical_tickets.rb
+++ b/db/migrate/20170603095900_create_physical_tickets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreatePhysicalTickets < ActiveRecord::Migration
   def change
     create_table :physical_tickets do |t|
diff --git a/db/migrate/20170629162450_add_short_name_to_tracks.rb b/db/migrate/20170629162450_add_short_name_to_tracks.rb
index cbc6b431..65e62256 100644
--- a/db/migrate/20170629162450_add_short_name_to_tracks.rb
+++ b/db/migrate/20170629162450_add_short_name_to_tracks.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 class AddShortNameToTracks < ActiveRecord::Migration
-  class TmpProgram < ActiveRecord::Base
+  class TmpProgram < ApplicationRecord
     self.table_name = 'programs'
   end
 
-  class TmpTrack < ActiveRecord::Base
+  class TmpTrack < ApplicationRecord
     self.table_name = 'tracks'
   end
 
diff --git a/db/migrate/20170629232817_add_ticket_layout_to_conferences.rb b/db/migrate/20170629232817_add_ticket_layout_to_conferences.rb
index c07f85c3..faf67332 100644
--- a/db/migrate/20170629232817_add_ticket_layout_to_conferences.rb
+++ b/db/migrate/20170629232817_add_ticket_layout_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTicketLayoutToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :ticket_layout, :integer, default: 0
diff --git a/db/migrate/20170705075039_add_state_cfp_active_and_submitter_reference_to_tracks.rb b/db/migrate/20170705075039_add_state_cfp_active_and_submitter_reference_to_tracks.rb
index 9cb7f7de..b42cf9c2 100644
--- a/db/migrate/20170705075039_add_state_cfp_active_and_submitter_reference_to_tracks.rb
+++ b/db/migrate/20170705075039_add_state_cfp_active_and_submitter_reference_to_tracks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddStateCfpActiveAndSubmitterReferenceToTracks < ActiveRecord::Migration
   def change
     add_column :tracks, :state, :string
diff --git a/db/migrate/20170711102511_create_ticket_scannings.rb b/db/migrate/20170711102511_create_ticket_scannings.rb
index d1879f68..12c20eb1 100644
--- a/db/migrate/20170711102511_create_ticket_scannings.rb
+++ b/db/migrate/20170711102511_create_ticket_scannings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateTicketScannings < ActiveRecord::Migration
   def change
     create_table :ticket_scannings do |t|
diff --git a/db/migrate/20170712120556_add_room_and_dates_to_tracks.rb b/db/migrate/20170712120556_add_room_and_dates_to_tracks.rb
index fb8a064b..6c2d92b9 100644
--- a/db/migrate/20170712120556_add_room_and_dates_to_tracks.rb
+++ b/db/migrate/20170712120556_add_room_and_dates_to_tracks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRoomAndDatesToTracks < ActiveRecord::Migration
   def change
     add_reference :tracks, :room, index: true, foreign_key: true
diff --git a/db/migrate/20170715131706_make_track_state_not_null_and_add_default_value.rb b/db/migrate/20170715131706_make_track_state_not_null_and_add_default_value.rb
index 3d2520cf..beae99cc 100644
--- a/db/migrate/20170715131706_make_track_state_not_null_and_add_default_value.rb
+++ b/db/migrate/20170715131706_make_track_state_not_null_and_add_default_value.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class MakeTrackStateNotNullAndAddDefaultValue < ActiveRecord::Migration
-  class TmpTrack < ActiveRecord::Base
+  class TmpTrack < ApplicationRecord
     self.table_name = 'tracks'
   end
 
diff --git a/db/migrate/20170720134353_make_track_cfp_active_not_null.rb b/db/migrate/20170720134353_make_track_cfp_active_not_null.rb
index 0f75d046..cfc8b1a5 100644
--- a/db/migrate/20170720134353_make_track_cfp_active_not_null.rb
+++ b/db/migrate/20170720134353_make_track_cfp_active_not_null.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 class MakeTrackCfpActiveNotNull < ActiveRecord::Migration
-  class TmpTrack < ActiveRecord::Base
+  class TmpTrack < ApplicationRecord
     self.table_name = 'tracks'
   end
 
diff --git a/db/migrate/20170721001700_add_index_to_physical_tickets.rb b/db/migrate/20170721001700_add_index_to_physical_tickets.rb
index 46a0b8c0..042430fe 100644
--- a/db/migrate/20170721001700_add_index_to_physical_tickets.rb
+++ b/db/migrate/20170721001700_add_index_to_physical_tickets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIndexToPhysicalTickets < ActiveRecord::Migration
   def change
     add_column :physical_tickets, :token, :string
diff --git a/db/migrate/20170721184810_add_custom_domain_to_conferences.rb b/db/migrate/20170721184810_add_custom_domain_to_conferences.rb
index d5aef4fd..a3e2897b 100644
--- a/db/migrate/20170721184810_add_custom_domain_to_conferences.rb
+++ b/db/migrate/20170721184810_add_custom_domain_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCustomDomainToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :custom_domain, :string
diff --git a/db/migrate/20170726065629_add_relevance_to_tracks.rb b/db/migrate/20170726065629_add_relevance_to_tracks.rb
index 215200c1..7db35227 100644
--- a/db/migrate/20170726065629_add_relevance_to_tracks.rb
+++ b/db/migrate/20170726065629_add_relevance_to_tracks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRelevanceToTracks < ActiveRecord::Migration
   def change
     add_column :tracks, :relevance, :text
diff --git a/db/migrate/20170727081731_add_include_booths_to_splashpages.rb b/db/migrate/20170727081731_add_include_booths_to_splashpages.rb
index da11ea8d..ea5882c1 100644
--- a/db/migrate/20170727081731_add_include_booths_to_splashpages.rb
+++ b/db/migrate/20170727081731_add_include_booths_to_splashpages.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddIncludeBoothsToSplashpages < ActiveRecord::Migration
   def change
     add_column :splashpages, :include_booths, :boolean
diff --git a/db/migrate/20170728182033_add_booth_limit_to_conferences.rb b/db/migrate/20170728182033_add_booth_limit_to_conferences.rb
index 60643784..ae0f1410 100644
--- a/db/migrate/20170728182033_add_booth_limit_to_conferences.rb
+++ b/db/migrate/20170728182033_add_booth_limit_to_conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddBoothLimitToConferences < ActiveRecord::Migration
   def change
     add_column :conferences, :booth_limit, :integer, default: 0
diff --git a/db/migrate/20170731161207_add_booths_to_email_settings.rb b/db/migrate/20170731161207_add_booths_to_email_settings.rb
index 0b3a7a87..5df76759 100644
--- a/db/migrate/20170731161207_add_booths_to_email_settings.rb
+++ b/db/migrate/20170731161207_add_booths_to_email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddBoothsToEmailSettings < ActiveRecord::Migration
   def change
     add_column :email_settings, :send_on_booths_acceptance, :boolean, default: false
diff --git a/db/migrate/20170807092805_add_registration_ticket_to_tickets.rb b/db/migrate/20170807092805_add_registration_ticket_to_tickets.rb
index 0ee2410d..c2e4fd8e 100644
--- a/db/migrate/20170807092805_add_registration_ticket_to_tickets.rb
+++ b/db/migrate/20170807092805_add_registration_ticket_to_tickets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddRegistrationTicketToTickets < ActiveRecord::Migration
   def change
     add_column :tickets, :registration_ticket, :boolean, default: false
diff --git a/db/migrate/20170809120927_add_track_reference_to_schedule.rb b/db/migrate/20170809120927_add_track_reference_to_schedule.rb
index 2c2d7f1c..b98fca24 100644
--- a/db/migrate/20170809120927_add_track_reference_to_schedule.rb
+++ b/db/migrate/20170809120927_add_track_reference_to_schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTrackReferenceToSchedule < ActiveRecord::Migration
   def change
     add_reference :schedules, :track, index: true, foreign_key: true
diff --git a/db/migrate/20170814174637_add_selected_schedule_to_tracks.rb b/db/migrate/20170814174637_add_selected_schedule_to_tracks.rb
index 05b7d417..bedc96c3 100644
--- a/db/migrate/20170814174637_add_selected_schedule_to_tracks.rb
+++ b/db/migrate/20170814174637_add_selected_schedule_to_tracks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddSelectedScheduleToTracks < ActiveRecord::Migration
   def change
     add_column :tracks, :selected_schedule_id, :integer
diff --git a/db/migrate/20170905110034_add_description_to_cfps.rb b/db/migrate/20170905110034_add_description_to_cfps.rb
index a4976ee2..968a907c 100644
--- a/db/migrate/20170905110034_add_description_to_cfps.rb
+++ b/db/migrate/20170905110034_add_description_to_cfps.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddDescriptionToCfps < ActiveRecord::Migration
   def change
     add_column :cfps, :description, :text
diff --git a/db/migrate/20170924190528_add_amount_paid_to_ticket_purchases.rb b/db/migrate/20170924190528_add_amount_paid_to_ticket_purchases.rb
index 5e732d4c..f3357ee3 100644
--- a/db/migrate/20170924190528_add_amount_paid_to_ticket_purchases.rb
+++ b/db/migrate/20170924190528_add_amount_paid_to_ticket_purchases.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddAmountPaidToTicketPurchases < ActiveRecord::Migration
   def change
     add_column :ticket_purchases, :amount_paid, :float, default: 0
diff --git a/db/migrate/20171118113113_change_visit_id_type_of_ahoy_events_to_integer.rb b/db/migrate/20171118113113_change_visit_id_type_of_ahoy_events_to_integer.rb
index 61415970..58b08609 100644
--- a/db/migrate/20171118113113_change_visit_id_type_of_ahoy_events_to_integer.rb
+++ b/db/migrate/20171118113113_change_visit_id_type_of_ahoy_events_to_integer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ChangeVisitIdTypeOfAhoyEventsToInteger < ActiveRecord::Migration[5.0]
   def change
     change_column :ahoy_events, :visit_id, :integer, limit: nil
diff --git a/db/migrate/20171130172334_rebuild_conference_pictures.rb b/db/migrate/20171130172334_rebuild_conference_pictures.rb
index a8d74bce..c19ae041 100644
--- a/db/migrate/20171130172334_rebuild_conference_pictures.rb
+++ b/db/migrate/20171130172334_rebuild_conference_pictures.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RebuildConferencePictures < ActiveRecord::Migration
   def up
     Conference.all.each do |conference|
diff --git a/db/migrate/20171201163628_add_mastodon_to_contact.rb b/db/migrate/20171201163628_add_mastodon_to_contact.rb
index 9b022019..a3cc50b6 100644
--- a/db/migrate/20171201163628_add_mastodon_to_contact.rb
+++ b/db/migrate/20171201163628_add_mastodon_to_contact.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddMastodonToContact < ActiveRecord::Migration
   def change
     add_column :contacts, :mastodon, :string
diff --git a/db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb b/db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb
index ce8d3c11..ea2a1542 100644
--- a/db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb
+++ b/db/migrate/20180226032958_add_created_at_and_updated_at_to_event_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddCreatedAtAndUpdatedAtToEventTypes < ActiveRecord::Migration[5.0]
   def up
     add_column :event_types, :created_at, :datetime
diff --git a/db/migrate/20180313012253_add_timestamps_to_tickets.rb b/db/migrate/20180313012253_add_timestamps_to_tickets.rb
index 85e8407e..eb2838db 100644
--- a/db/migrate/20180313012253_add_timestamps_to_tickets.rb
+++ b/db/migrate/20180313012253_add_timestamps_to_tickets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AddTimestampsToTickets < ActiveRecord::Migration[5.0]
   def up
     add_column :tickets, :created_at, :datetime
diff --git a/db/seeds.rb b/db/seeds.rb
index bf3567e0..88d2d10a 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file should contain all the record creation needed to seed the database with its default values.
 # The data can then be loaded with the rake db:seed (or created alongside the db with db:setup).
 #
diff --git a/lib/tasks/capitalize_colors.rake b/lib/tasks/capitalize_colors.rake
index 48b9b4ef..aa80c688 100644
--- a/lib/tasks/capitalize_colors.rake
+++ b/lib/tasks/capitalize_colors.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Catitalize tracks, event types and difficult levels colors'
 
diff --git a/lib/tasks/cleardb.rake b/lib/tasks/cleardb.rake
index ca2a32ae..2cf19a2a 100644
--- a/lib/tasks/cleardb.rake
+++ b/lib/tasks/cleardb.rake
@@ -1,8 +1,8 @@
+# frozen_string_literal: true
+
 namespace :db do
   desc 'setup DATABASE_URL from CLEARDB_DATABASE_URL in config/database.yml'
   task 'cleardb_env' do
-    unless ENV['CLEARDB_DATABASE_URL'].nil?
-      FileUtils.copy_file('config/database.yml.heroku', 'config/database.yml')
-    end
+    FileUtils.copy_file('config/database.yml.heroku', 'config/database.yml') unless ENV['CLEARDB_DATABASE_URL'].nil?
   end
 end
diff --git a/lib/tasks/data.rake b/lib/tasks/data.rake
index 215a1efe..3935b1be 100644
--- a/lib/tasks/data.rake
+++ b/lib/tasks/data.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Nullify wrong foreign keys'
 
@@ -20,7 +22,7 @@ namespace :data do
     if collection.any?
       puts "IDs: #{collection.map(&:id)}"
       collection.each do |item|
-        item.send(attribute+'=', nil)
+        item.send(attribute + '=', nil)
         item.save!
       end
       puts "Fixed #{attribute}!"
diff --git a/lib/tasks/data_demo.rake b/lib/tasks/data_demo.rake
index 8debfe49..6ad5ec4b 100644
--- a/lib/tasks/data_demo.rake
+++ b/lib/tasks/data_demo.rake
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Create demo data using our factories'
   task demo: :environment do
     include FactoryGirl::Syntax::Methods
 
-    conference = create(:full_conference, title: 'Open Source Event Manager Demo', short_title: 'osemdemo' ,description: "This is a [Open Source Event Manager](http://osem.io/) demo instance. You can log in as **admin** with the password **password123** or just you just [sign up](/accounts/sign_up) with your own user. We hope you enjoy checking out all the functionality, if you have questions don't hesitate to [contact us](http://osem.io/#contact)!\r\n\r\n## Data will be destroyed every thirty minutes or whenever someone updates the [OSEM source code on github](https://github.com/openSUSE/osem/commits/master).")
-    conference.contact.update_attributes(email: 'osemdemo@osem.io', sponsor_email: 'osemdemo@osem.io')
+    conference = create(:full_conference, title: 'Open Source Event Manager Demo', short_title: 'osemdemo', description: "This is a [Open Source Event Manager](http://osem.io/) demo instance. You can log in as **admin** with the password **password123** or just you just [sign up](/accounts/sign_up) with your own user. We hope you enjoy checking out all the functionality, if you have questions don't hesitate to [contact us](http://osem.io/#contact)!\r\n\r\n## Data will be destroyed every thirty minutes or whenever someone updates the [OSEM source code on github](https://github.com/openSUSE/osem/commits/master).")
+    conference.contact.update(email: 'osemdemo@osem.io', sponsor_email: 'osemdemo@osem.io')
     create(:admin, email: 'admin@osem.io', username: 'admin', password: 'password123', password_confirmation: 'password123')
   end
 end
diff --git a/lib/tasks/demo_data_for_development.rake b/lib/tasks/demo_data_for_development.rake
index 5be30c8e..95c0a694 100644
--- a/lib/tasks/demo_data_for_development.rake
+++ b/lib/tasks/demo_data_for_development.rake
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Create demo data for our local development'
   task test: :environment do
     include FactoryGirl::Syntax::Methods
 
-    def generate_program conference
+    def generate_program(conference)
       program = conference.program
       user1 = create(:user)
       user2 = create(:user)
@@ -12,7 +14,7 @@ namespace :data do
 
       selected_schedule = create(:schedule, program: program)
       demo_schedule = create(:schedule, program: program)
-      program.update_attributes!(selected_schedule: selected_schedule)
+      program.update!(selected_schedule: selected_schedule)
 
       create(:event, program: program, title: 'Demo Event', abstract: 'This is a demo event instance whose state not defined.')
       create(:event, program: program, title: 'Demo Rejected Event', state: 'rejected', abstract: 'This is demo event instance in a rejected state.')
@@ -48,9 +50,9 @@ namespace :data do
     # So that events can be created without any failure in validations.
     conference = create(:full_conference, title: 'Jangouts Demo Conference', short_title: 'jangouts', start_date: 7.days.ago, end_date: 6.days.from_now, start_hour: 15, end_hour: 20, description: 'This is a full conference demo instance happened in the past. It contains open cfp, venue/rooms, submitted talks by multiple speakers, partly confirmed talks and multiple schedules.')
     generate_program conference
-    conference.program.cfp.update_attributes!(start_date: 4.days.ago, end_date: 2.days.ago)
-    conference.update_attributes!(end_date: 1.day.ago)
-    conference.registration_period.update_attributes!(start_date: 9.days.ago, end_date: 8.days.ago)
+    conference.program.cfp.update!(start_date: 4.days.ago, end_date: 2.days.ago)
+    conference.update!(end_date: 1.day.ago)
+    conference.registration_period.update!(start_date: 9.days.ago, end_date: 8.days.ago)
 
     # This is a conference that will happen in the future
     # It only has a registration period and unscheduled events
diff --git a/lib/tasks/dump_db.rake b/lib/tasks/dump_db.rake
index 6738f409..71b557f4 100644
--- a/lib/tasks/dump_db.rake
+++ b/lib/tasks/dump_db.rake
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 require 'yaml'
 task :dump_db do
-  yaml = YAML.load_file("config/database.yml")
-  conf = yaml["production"]
-  filename = "#{conf["database"]}-#{Time.now.strftime("%Y-%m-%d-%H:%M:%S:%L")}.sql"
-  if conf["adapter"] == 'mysql2'
-    system "mysqldump -u #{conf["username"]} --password=#{conf["password"]} -h #{conf["host"]} #{conf["database"]} > ~/#{filename}"
+  yaml = YAML.load_file('config/database.yml')
+  conf = yaml['production']
+  filename = "#{conf['database']}-#{Time.now.strftime('%Y-%m-%d-%H:%M:%S:%L')}.sql"
+  if conf['adapter'] == 'mysql2'
+    system "mysqldump -u #{conf['username']} --password=#{conf['password']} -h #{conf['host']} #{conf['database']} > ~/#{filename}"
   else
-    puts "Error: This rake task only works for MYSQL"
+    puts 'Error: This rake task only works for MYSQL'
   end
 end
diff --git a/lib/tasks/event_attatchments.rake b/lib/tasks/event_attatchments.rake
index 46985168..93d83600 100644
--- a/lib/tasks/event_attatchments.rake
+++ b/lib/tasks/event_attatchments.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :db do
   desc 'Destroy event_attachments versions'
 
@@ -5,4 +7,4 @@ namespace :db do
     PaperTrail::Version.where(item_type: 'EventAttachment').try(:destroy_all)
     puts 'Version records with event_attachment have been destroyed'
   end
-end
\ No newline at end of file
+end
diff --git a/lib/tasks/events_registrations.rake b/lib/tasks/events_registrations.rake
index 726b739b..6b6030bc 100644
--- a/lib/tasks/events_registrations.rake
+++ b/lib/tasks/events_registrations.rake
@@ -1,25 +1,24 @@
+# frozen_string_literal: true
+
 namespace :events_registrations do
-  desc "Deletes dupicate entries"
+  desc 'Deletes dupicate entries'
   task deduplicate: :environment do
-    if ActiveRecord::Migrator.get_all_versions.include? 20160403214841
-      duplicates = EventsRegistration.all.map { |er| er.id if er.valid? == false}.compact
+    if ActiveRecord::Migrator.get_all_versions.include? 20_160_403_214_841
+      duplicates = EventsRegistration.all.map { |er| er.id if er.valid? == false }.compact
 
       puts "Duplicates found: #{duplicates.count}"
-      if duplicates.count > 0
-        puts "With IDs: #{duplicates}"
-      end
+      puts "With IDs: #{duplicates}" if duplicates.count > 0
 
       EventsRegistration.all.each do |er|
         records = EventsRegistration.where(registration_id: er.registration_id, event_id: er.event_id)
-        if records.count > 1
-          # Iterate through duplicates (excluding 1st record)
-          (1..(records.count - 1)).each do |i|
-            puts "Deleting EventsRegistration record with ID #{records[i].id} ..."
-            if records[i].destroy
-              puts 'Succeeded!'
-            else
-              puts 'Faild!'
-            end
+        next unless records.count > 1
+        # Iterate through duplicates (excluding 1st record)
+        (1..(records.count - 1)).each do |i|
+          puts "Deleting EventsRegistration record with ID #{records[i].id} ..."
+          if records[i].destroy
+            puts 'Succeeded!'
+          else
+            puts 'Faild!'
           end
         end
       end
diff --git a/lib/tasks/factory_girl.rake b/lib/tasks/factory_girl.rake
index bccc1b66..9de62236 100644
--- a/lib/tasks/factory_girl.rake
+++ b/lib/tasks/factory_girl.rake
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 namespace :factory_girl do
-  desc "Verify that all FactoryGirl factories are valid"
+  desc 'Verify that all FactoryGirl factories are valid'
   task lint: :environment do
     if Rails.env.test?
       begin
diff --git a/lib/tasks/logo.rake b/lib/tasks/logo.rake
index 468b6d72..082bded4 100644
--- a/lib/tasks/logo.rake
+++ b/lib/tasks/logo.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   namespace :migrate do
     desc 'Resize existing logo of sponsors after change in image manipulation specifications'
diff --git a/lib/tasks/migrate_config.rake b/lib/tasks/migrate_config.rake
index 452a061f..ab077c31 100644
--- a/lib/tasks/migrate_config.rake
+++ b/lib/tasks/migrate_config.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   namespace :migrate do
     desc 'Create a dotenv file from config/config.yml'
@@ -14,8 +16,8 @@ namespace :data do
       config_yml = Rails.root.join('config', 'config.yml')
       begin
         CONFIG = YAML.load_file(config_yml)[Rails.env]
-      rescue
-        CONFIG = {}
+      rescue StandardError
+        CONFIG = {}.freeze
       end
 
       # Write the dotenv file
@@ -23,7 +25,7 @@ namespace :data do
       dot_env.puts "OSEM_NAME=\"#{CONFIG['name']}\""
       dot_env.puts "OSEM_HOSTNAME=\"#{CONFIG['url_for_emails']}\""
       dot_env.puts "OSEM_EMAIL_ADDRESS=\"#{CONFIG['sender_for_emails']}\""
-      dot_env.puts "OSEM_ICHAIN_ENABLED=\"#{CONFIG['authentication']['ichain']['enabled']}\"" if CONFIG.has_key?(:authentication)
+      dot_env.puts "OSEM_ICHAIN_ENABLED=\"#{CONFIG['authentication']['ichain']['enabled']}\"" if CONFIG.key?(:authentication)
       dot_env.puts "OSEM_TRANSIFEX_APIKEY=\"#{CONFIG['transifex_live_api_key']}\""
       dot_env.puts "OSEM_ERRBIT_HOST=\"#{CONFIG['errbit_host']}\""
       dot_env.puts "OSEM_FACTORY_LINT=\"#{CONFIG['factory_girl_lint']}\""
diff --git a/lib/tasks/normalize_resources.rake b/lib/tasks/normalize_resources.rake
index e05d0d69..6ee5f92d 100644
--- a/lib/tasks/normalize_resources.rake
+++ b/lib/tasks/normalize_resources.rake
@@ -1,12 +1,12 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Update resources with nil quantity/used fields'
   task normalize_resources: :environment do
     Resource.where('used is ? or quantity is ?', nil, nil).each do |resource|
       resource.used = 0 if resource.used.blank?
       resource.quantity = resource.used if resource.quantity.blank?
-      unless resource.save
-        puts "Failed to update resource #{resource.name} (ID #{resource.id})"
-      end
+      puts "Failed to update resource #{resource.name} (ID #{resource.id})" unless resource.save
     end
   end
 end
diff --git a/lib/tasks/roles.rake b/lib/tasks/roles.rake
index c29d0e24..19848eab 100644
--- a/lib/tasks/roles.rake
+++ b/lib/tasks/roles.rake
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 namespace :roles do
   desc 'Adds back deleted roles to all conferences'
   task add: :environment do
-
     Organization.all.each do |org|
       Role.where(name: 'organization_admin', resource: org).first_or_create(description: 'For the administrators of an organization and its conferences')
     end
@@ -16,4 +17,3 @@ namespace :roles do
     puts 'All done!'
   end
 end
-
diff --git a/lib/tasks/several_schedules.rake b/lib/tasks/several_schedules.rake
index f83b9664..9c69b8a7 100644
--- a/lib/tasks/several_schedules.rake
+++ b/lib/tasks/several_schedules.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Move the start_time and room attributes from Event to EventSchedule'
 
@@ -7,16 +9,15 @@ namespace :data do
       program.selected_schedule = schedule
       program.save
       program.events.each do |event|
-        unless event.start_time.nil? && event.room_id.nil?
-          # we can not use .room as this relation has been removed
-          EventSchedule.create(event: event,
-                               schedule: schedule,
-                               start_time: event.start_time,
-                               room_id: event.room_id)
-          event.start_time = nil
-          event.room_id = nil
-          event.save
-        end
+        next if event.start_time.nil? && event.room_id.nil?
+        # we can not use .room as this relation has been removed
+        EventSchedule.create(event: event,
+                             schedule: schedule,
+                             start_time: event.start_time,
+                             room_id: event.room_id)
+        event.start_time = nil
+        event.room_id = nil
+        event.save
       end
     end
     puts 'The start_time and room attributes has been moved from Event to EventSchedule'
diff --git a/lib/tasks/user.rake b/lib/tasks/user.rake
index 97e56e40..6ab7258a 100644
--- a/lib/tasks/user.rake
+++ b/lib/tasks/user.rake
@@ -1,21 +1,20 @@
-namespace :user do
-  desc "Makes is_admin attribute true for user based on the supplied email address."
-  task :admin, [:email] => :environment do |t, args|
+# frozen_string_literal: true
 
+namespace :user do
+  desc 'Makes is_admin attribute true for user based on the supplied email address.'
+  task :admin, [:email] => :environment do |_t, args|
     # Check if an email address was supplied
-    fail 'You need to define the email address of the user you want to make an admin.' unless args.email
+    raise 'You need to define the email address of the user you want to make an admin.' unless args.email
 
     user = User.find_by(email: args.email)
     # Check if a user is found based on the supplied email address
-    fail "There is no user with email #{args.email}!" unless user
+    raise "There is no user with email #{args.email}!" unless user
 
-    if user.update_columns(is_admin: true)
-      puts "User with email #{args.email} is now an admin!"
-    end
+    puts "User with email #{args.email} is now an admin!" if user.update_columns(is_admin: true)
   end
 
-  desc "Set email_public attrubute true for all users"
-  task :set_email_public => :environment do
+  desc 'Set email_public attrubute true for all users'
+  task set_email_public: :environment do
     User.update_all email_public: true
   end
 end
diff --git a/lib/tasks/version.rake b/lib/tasks/version.rake
index a25653c6..813a9cf4 100644
--- a/lib/tasks/version.rake
+++ b/lib/tasks/version.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 namespace :data do
   desc 'Sets conference_id in all pre-existing PaperTrail::Version objects'
   task set_conference_in_versions: :environment do
@@ -5,7 +7,7 @@ namespace :data do
     PaperTrail::Version.where(conference_id: nil, item_type: %w[Conference Event]).each do |version|
       # All pre-existing versions are either of Conference or Event
       if version.item_type == 'Conference'
-        version.update_attributes(conference_id: version.item_id)
+        version.update(conference_id: version.item_id)
 
       elsif version.item_type == 'Event'
         event = (version.item || version.reify || version.next.reify)
@@ -24,7 +26,7 @@ namespace :data do
                           puts "Setting conference_id value failed for PaperTrail::Version object with ID=#{version.id}"
                           nil
                         end
-        version.update_attributes(conference_id: conference_id)
+        version.update(conference_id: conference_id)
       end
     end
     puts 'All done!'
diff --git a/spec/controllers/admin/booths_controller_spec.rb b/spec/controllers/admin/booths_controller_spec.rb
index 37004531..4fee4038 100644
--- a/spec/controllers/admin/booths_controller_spec.rb
+++ b/spec/controllers/admin/booths_controller_spec.rb
@@ -1,24 +1,24 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::BoothsController do
-
   let(:admin) { create(:admin) }
   let(:conference) { create(:conference) }
   let(:booth) { create(:booth, title: 'Title', conference: conference) }
   let(:admin) { create(:admin) }
 
   context 'not logged in user' do
-
     describe 'GET index' do
       it 'does not render admin/booths#index' do
-        get :index, conference_id: conference.short_title
+        get :index, params: { conference_id: conference.short_title }
         expect(response).to redirect_to(user_session_path)
       end
     end
 
     describe 'GET show' do
       it 'does not render admin/booths#show' do
-        get :show, id: booth.id, conference_id: conference.short_title
+        get :show, params: { id: booth.id, conference_id: conference.short_title }
         expect(response).to redirect_to(user_session_path)
       end
     end
@@ -30,7 +30,7 @@ describe Admin::BoothsController do
     end
 
     describe 'GET index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'assigns attributes for booths' do
         expect(assigns(:booths)).to eq([booth])
@@ -42,7 +42,7 @@ describe Admin::BoothsController do
     end
 
     describe 'GET new' do
-      before { get :new, conference_id: conference.short_title }
+      before { get :new, params: { conference_id: conference.short_title } }
 
       it 'assigns attributes for booths' do
         expect(assigns(:booth)).to be_a_new(Booth)
@@ -55,11 +55,11 @@ describe Admin::BoothsController do
 
     describe 'POST #create' do
       context 'successfully created' do
-        before { post :create, booth: attributes_for(:booth), conference_id: conference.short_title }
+        before { post :create, params: { booth: attributes_for(:booth), conference_id: conference.short_title } }
 
         it 'creates a new booth' do
           expected = expect do
-            post :create, booth: attributes_for(:booth), conference_id: conference.short_title
+            post :create, params: { booth: attributes_for(:booth), conference_id: conference.short_title }
           end
           expected.to change { Booth.count }.by(1)
         end
@@ -78,11 +78,11 @@ describe Admin::BoothsController do
       end
 
       context 'create action fails' do
-        before { post :create, booth: attributes_for(:booth, title: ''), conference_id: conference.short_title }
+        before { post :create, params: { booth: attributes_for(:booth, title: ''), conference_id: conference.short_title } }
 
         it 'does not create any record' do
           expected = expect do
-            post :create, booth: attributes_for(:booth, title: ''), conference_id: conference.short_title
+            post :create, params: { booth: attributes_for(:booth, title: ''), conference_id: conference.short_title }
           end
           expected.to_not change(Booth, :count)
         end
@@ -98,7 +98,7 @@ describe Admin::BoothsController do
     end
 
     describe 'GET #edit' do
-      before { get :edit, id: booth.id, conference_id: conference.short_title }
+      before { get :edit, params: { id: booth.id, conference_id: conference.short_title } }
 
       it 'renders edit template' do
         expect(response).to render_template('edit')
@@ -111,7 +111,7 @@ describe Admin::BoothsController do
 
     describe 'PATCH #update' do
       context 'updates suchessfully' do
-        before { patch :update, id: booth.id, booth: attributes_for(:booth, title: 'different'), conference_id: conference.short_title }
+        before { patch :update, params: { id: booth.id, booth: attributes_for(:booth, title: 'different'), conference_id: conference.short_title } }
         it 'redirects to admin booth index path' do
           expect(response).to redirect_to admin_conference_booths_path
         end
diff --git a/spec/controllers/admin/comments_controller_spec.rb b/spec/controllers/admin/comments_controller_spec.rb
index 23b6b88a..89526e89 100644
--- a/spec/controllers/admin/comments_controller_spec.rb
+++ b/spec/controllers/admin/comments_controller_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::CommentsController, type: :controller do
-
   # It is necessary to use bang version of let to build roles before user
   let(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
diff --git a/spec/controllers/admin/conferences_controller_spec.rb b/spec/controllers/admin/conferences_controller_spec.rb
index 23e6afd2..9500dcbb 100644
--- a/spec/controllers/admin/conferences_controller_spec.rb
+++ b/spec/controllers/admin/conferences_controller_spec.rb
@@ -1,10 +1,11 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::ConferencesController do
-
   # It is necessary to use bang version of let to build roles before user
   let!(:organization) { create(:organization, name: 'organization') }
-  let!(:conference) { create(:conference, organization: organization, end_date: Date.new(2014, 05, 26) + 15) }
+  let!(:conference) { create(:conference, organization: organization, end_date: Date.new(2014, 0o5, 26) + 15) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let!(:organization_admin_role) { Role.find_by(name: 'organization_admin', resource: organization) }
   let(:organization_admin) { create(:user, role_ids: organization_admin_role.id) }
@@ -16,32 +17,33 @@ describe Admin::ConferencesController do
     describe 'PATCH #update' do
       context 'valid attributes' do
         it 'locates the requested conference' do
-          patch :update, id: conference.short_title, conference: attributes_for(:conference, title: 'Example Con')
+          patch :update, params: { id: conference.short_title, conference: attributes_for(:conference, title: 'Example Con') }
           expect(assigns(:conference)).to eq(conference)
         end
 
         it 'changes conference attributes' do
-          patch :update, id: conference.short_title, conference:
+          patch :update, params: { id: conference.short_title, conference:
               attributes_for(:conference, title: 'Example Con',
-                                          short_title: 'ExCon')
+                                          short_title: 'ExCon') }
           conference.reload
           expect(conference.title).to eq('Example Con')
           expect(conference.short_title).to eq('ExCon')
         end
 
         it 'redirects to the updated conference' do
-          patch :update, id: conference.short_title, conference:
-              attributes_for(:conference, title: 'Example Con')
+          patch :update, params: { id: conference.short_title, conference:
+              attributes_for(:conference, title: 'Example Con') }
           conference.reload
           expect(response).to redirect_to edit_admin_conference_path(
-                                              conference.short_title)
+            conference.short_title
+          )
         end
 
         it 'sends email notification on conference date update' do
           mailer = double
           allow(mailer).to receive(:deliver)
           conference.email_settings = create(:email_settings)
-          patch :update, id: conference.short_title, conference: attributes_for(:conference, start_date: Time.zone.today + 2.days, end_date: Time.zone.today + 4.days)
+          patch :update, params: { id: conference.short_title, conference: attributes_for(:conference, start_date: Time.zone.today + 2.days, end_date: Time.zone.today + 4.days) }
           conference.reload
           allow(Mailbot).to receive(:conference_date_update_mail).and_return(mailer)
         end
@@ -49,50 +51,51 @@ describe Admin::ConferencesController do
 
       context 'invalid attributes' do
         it 'does not change conference attributes' do
-          patch :update, id: conference.short_title, conference:
+          patch :update, params: { id: conference.short_title, conference:
               attributes_for(:conference, title: 'Example Con',
-                                          short_title: nil)
+                                          short_title: nil) }
 
           conference.reload
           expect(flash[:error])
-              .to eq("Updating conference failed. Short title can't be blank.")
+            .to eq("Updating conference failed. Short title can't be blank.")
           expect(conference.title).to eq(conference.title)
           expect(conference.short_title).to eq(conference.short_title)
         end
 
         it 're-renders the #show template' do
-          patch :update, id: conference.short_title, conference:
+          patch :update, params: { id: conference.short_title, conference:
               attributes_for(:conference, title: 'Example Con',
-                                          short_title: nil)
+                                          short_title: nil) }
 
           expect(flash[:error])
-              .to eq("Updating conference failed. Short title can't be blank.")
+            .to eq("Updating conference failed. Short title can't be blank.")
           expect(response).to redirect_to edit_admin_conference_path(
-                                              conference.short_title)
+            conference.short_title
+          )
         end
       end
     end
 
     describe 'GET #edit' do
       it 'assigns the requested conference to conference' do
-        get :edit, id: conference.short_title
+        get :edit, params: { id: conference.short_title }
         expect(assigns(:conference)).to eq conference
       end
 
       it 'renders the show template' do
-        get :edit, id: conference.short_title
+        get :edit, params: { id: conference.short_title }
         expect(response).to render_template :edit
       end
     end
 
     describe 'GET #show' do
       it 'assigns the requested conference to conference' do
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:conference)).to eq conference
       end
 
       it 'renders the show template' do
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(response).to render_template :show
       end
 
@@ -101,11 +104,11 @@ describe Admin::ConferencesController do
         create(:event, program: conference.program)
         workshop = create(:event_type, title: 'Workshop', color: '#000000', program: conference.program)
         lecture = create(:event_type, title: 'Lecture', color: '#ffffff', program: conference.program)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:event_type_distribution_withdrawn)).to be_empty
         create(:event, program: conference.program, state: 'withdrawn', event_type: lecture)
         create(:event, program: conference.program, state: 'withdrawn', event_type: workshop)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:event_type_distribution_withdrawn)).not_to be_empty
         result = {}
         result['Workshop'] = {
@@ -122,13 +125,13 @@ describe Admin::ConferencesController do
       it 'assigns conference withdrawn difficulty level distribution to difficulty_levels_distribution_withdrawn' do
         conference
         create(:event, program: conference.program)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:difficulty_levels_distribution_withdrawn)).to be_empty
         easy = create(:difficulty_level, title: 'Easy', color: '#000000')
         hard = create(:difficulty_level, title: 'Hard', color: '#ffffff')
         create(:event, program: conference.program, state: 'withdrawn', difficulty_level: easy)
         create(:event, program: conference.program, state: 'withdrawn', difficulty_level: hard)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:difficulty_levels_distribution_withdrawn)).not_to be_empty
         result = {}
         result['Easy'] = {
@@ -145,13 +148,13 @@ describe Admin::ConferencesController do
       it 'assigns conference withdrawn track distribution to tracks_distribution_withdrawn' do
         conference
         create(:event, program: conference.program)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:tracks_distribution_withdrawn)).to be_empty
         track_one = create(:track, name: 'Track One', color: '#000000', program: conference.program)
         track_two = create(:track, name: 'Track Two', color: '#FFFFFF', program: conference.program)
         create(:event, program: conference.program, state: 'withdrawn', track: track_one)
         create(:event, program: conference.program, state: 'withdrawn', track: track_two)
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:tracks_distribution_withdrawn)).not_to be_empty
         result = {}
         result['Track One'] = {
@@ -177,7 +180,7 @@ describe Admin::ConferencesController do
 
         it 'assigns cfp_max an array with maximum weeks' do
           conference
-          date = Date.new(2014, 05, 26)
+          date = Date.new(2014, 0o5, 26)
           create(:cfp,
                  program: conference.program,
                  start_date: date,
@@ -195,9 +198,7 @@ describe Admin::ConferencesController do
 
       context 'no conferences' do
         it 'redirect to new conference' do
-          Conference.all.each do |c|
-            c.destroy
-          end
+          Conference.all.each(&:destroy)
           sign_in create(:admin)
           get :index
           expect(response).to redirect_to new_admin_conference_path
@@ -211,18 +212,19 @@ describe Admin::ConferencesController do
       context 'with valid attributes' do
         it 'saves the conference to the database' do
           expected = expect do
-            post :create, conference:
-                attributes_for(:conference, short_title: 'dps15', organization_id: organization.id)
+            post :create, params: { conference:
+                attributes_for(:conference, short_title: 'dps15', organization_id: organization.id) }
           end
           expected.to change { Conference.count }.by 1
         end
 
         it 'redirects to conference#show' do
-          post :create, conference:
-              attributes_for(:conference, short_title: 'dps15', organization_id: organization.id)
+          post :create, params: { conference:
+              attributes_for(:conference, short_title: 'dps15', organization_id: organization.id) }
 
           expect(response).to redirect_to admin_conference_path(
-                                              assigns[:conference].short_title)
+            assigns[:conference].short_title
+          )
         end
 
         it 'creates roles for the conference' do
@@ -230,8 +232,8 @@ describe Admin::ConferencesController do
           info_desk_role = Role.find_by(name: 'info_desk', resource: conference)
           volunteers_coordinator_role = Role.find_by(name: 'volunteers_coordinator', resource: conference)
 
-          post :create, conference:
-              attributes_for(:conference, short_title: 'dps15')
+          post :create, params: { conference:
+              attributes_for(:conference, short_title: 'dps15') }
 
           expect(conference.roles.count).to eq 4
 
@@ -242,15 +244,15 @@ describe Admin::ConferencesController do
       context 'with invalid attributes' do
         it 'does not save the conference to the database' do
           expected = expect do
-            post :create, conference:
-                attributes_for(:conference, short_title: nil, organization_id: organization.id)
+            post :create, params: { conference:
+                attributes_for(:conference, short_title: nil, organization_id: organization.id) }
           end
           expected.to_not change { Conference.count }
         end
 
         it 're-renders the new template' do
-          post :create, conference:
-              attributes_for(:conference, short_title: nil, organization_id: organization.id)
+          post :create, params: { conference:
+              attributes_for(:conference, short_title: nil, organization_id: organization.id) }
           expect(response).to be_success
         end
       end
@@ -259,15 +261,15 @@ describe Admin::ConferencesController do
         it 'does not save the conference to the database' do
           conference
           expected = expect do
-            post :create, conference:
-                attributes_for(:conference, short_title: conference.short_title, organization_id: organization.id)
+            post :create, params: { conference:
+                attributes_for(:conference, short_title: conference.short_title, organization_id: organization.id) }
           end
           expected.to_not change { Conference.count }
         end
 
         it 're-renders the new template' do
           conference
-          post :create, conference: attributes_for(:conference, short_title: conference.short_title, organization_id: organization.id)
+          post :create, params: { conference: attributes_for(:conference, short_title: conference.short_title, organization_id: organization.id) }
           expect(response).to be_success
         end
       end
@@ -300,20 +302,16 @@ describe Admin::ConferencesController do
       it 'requires organizer privileges' do
         get :new
         expect(response).to redirect_to(send(path))
-        if message
-          expect(flash[:alert]).to match(/#{message}/)
-        end
+        expect(flash[:alert]).to match(/#{message}/) if message
       end
     end
 
     describe 'POST #create' do
       it 'requires organizer privileges' do
-        post :create, conference: attributes_for(:conference,
-                                                 short_title: 'ExCon', organization_id: organization.id)
+        post :create, params: { conference: attributes_for(:conference,
+                                                           short_title: 'ExCon', organization_id: organization.id) }
         expect(response).to redirect_to(send(path))
-        if message
-          expect(flash[:alert]).to match(/#{message}/)
-        end
+        expect(flash[:alert]).to match(/#{message}/) if message
       end
     end
   end
@@ -330,11 +328,9 @@ describe Admin::ConferencesController do
   shared_examples 'access as participant or guest' do |path, message|
     describe 'GET #show' do
       it 'requires organizer privileges' do
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(response).to redirect_to(send(path))
-        if message
-          expect(flash[:alert]).to match(/#{message}/)
-        end
+        expect(flash[:alert]).to match(/#{message}/) if message
       end
     end
 
@@ -342,21 +338,16 @@ describe Admin::ConferencesController do
       it 'requires organizer privileges' do
         get :index
         expect(response).to redirect_to(send(path))
-        if message
-          expect(flash[:alert]).to match(/#{message}/)
-        end
+        expect(flash[:alert]).to match(/#{message}/) if message
       end
     end
 
     describe 'PATCH #update' do
       it 'requires organizer privileges' do
-        patch :update, id: conference.short_title,
-                       conference: attributes_for(:conference,
-                                                  short_title: 'ExCon')
+        patch :update, params: { id: conference.short_title, conference: attributes_for(:conference,
+                                                                                        short_title: 'ExCon') }
         expect(response).to redirect_to(send(path))
-        if message
-          expect(flash[:alert]).to match(/#{message}/)
-        end
+        expect(flash[:alert]).to match(/#{message}/) if message
       end
     end
   end
@@ -371,7 +362,6 @@ describe Admin::ConferencesController do
   end
 
   describe 'guest access' do
-
     it_behaves_like 'access as participant or guest', :new_user_session_path
     it_behaves_like 'access as organizer, participant or guest', :new_user_session_path
   end
diff --git a/spec/controllers/admin/event_schedules_controller_spec.rb b/spec/controllers/admin/event_schedules_controller_spec.rb
index 6c1cfedd..48d2dc71 100644
--- a/spec/controllers/admin/event_schedules_controller_spec.rb
+++ b/spec/controllers/admin/event_schedules_controller_spec.rb
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::EventSchedulesController do
   let(:venue) { create(:venue) }
   let(:conference) { create(:conference, venue: venue) }
   let(:room) { create(:room, venue: venue) }
-  let(:schedule) { create(:schedule, program: conference.program)}
-  let(:event_schedule) { create(:event_schedule, schedule: schedule)}
+  let(:schedule) { create(:schedule, program: conference.program) }
+  let(:event_schedule) { create(:event_schedule, schedule: schedule) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let(:organizer) { create(:user, role_ids: organizer_role.id) }
 
@@ -18,16 +20,16 @@ describe Admin::EventSchedulesController do
     describe 'POST #create' do
       context 'with valid attributes' do
         let(:create_action) do
-          post :create, conference_id: conference.short_title, event_schedule:
+          post :create, params: { conference_id: conference.short_title, event_schedule:
                attributes_for(:event_schedule,
                               schedule_id: schedule.id,
                               event_id: create(:event, program: conference.program).id,
                               room_id: create(:room, venue: venue).id,
-                              start_time: conference.start_date + conference.start_hour.hours)
+                              start_time: conference.start_date + conference.start_hour.hours) }
         end
 
         it 'saves the event schedule to the database' do
-          expect{ create_action }.to change { EventSchedule.count }.by 1
+          expect { create_action }.to change { EventSchedule.count }.by 1
         end
 
         it 'has 200 status code' do
@@ -37,18 +39,17 @@ describe Admin::EventSchedulesController do
       end
 
       context 'with invalid attributes' do
-
         let(:create_action) do
-          post :create, conference_id: conference.short_title, event_schedule:
+          post :create, params: { conference_id: conference.short_title, event_schedule:
                attributes_for(:event_schedule,
                               schedule_id: schedule.id,
                               event_id: nil,
                               room_id: nil,
-                              start_time: nil)
+                              start_time: nil) }
         end
 
         it 'does not save the event schedule to the database' do
-          expect{ create_action }.to_not change { EventSchedule.count }
+          expect { create_action }.to_not change { EventSchedule.count }
         end
 
         it 'has 422 status code' do
@@ -61,12 +62,12 @@ describe Admin::EventSchedulesController do
     describe 'POST #update' do
       context 'with valid attributes' do
         before :each do
-          patch :update, id: event_schedule.id, conference_id: conference.short_title, event_schedule:
+          patch :update, params: { id: event_schedule.id, conference_id: conference.short_title, event_schedule:
                  attributes_for(:event_schedule,
                                 schedule_id: schedule.id,
                                 event_id: create(:event, program: conference.program).id,
                                 room_id: room.id,
-                                start_time: conference.start_date + conference.start_hour.hours)
+                                start_time: conference.start_date + conference.start_hour.hours) }
           event_schedule.reload
         end
 
@@ -85,15 +86,15 @@ describe Admin::EventSchedulesController do
 
       context 'with invalid attributes' do
         let(:update_action) do
-          patch :update, id: event_schedule.id, conference_id: conference.short_title, event_schedule:
+          patch :update, params: { id: event_schedule.id, conference_id: conference.short_title, event_schedule:
                attributes_for(:event_schedule,
                               schedule_id: schedule.id,
                               event_id: nil,
                               room_id: nil,
-                              start_time: nil)
+                              start_time: nil) }
         end
         it 'does not save the event schedule to the database' do
-          expect{ update_action }.to_not change { event_schedule }
+          expect { update_action }.to_not change { event_schedule }
         end
 
         it 'has 422 status code' do
@@ -105,11 +106,11 @@ describe Admin::EventSchedulesController do
 
     describe 'DELETE #destroy' do
       let(:destroy_action) do
-        delete :destroy, id: event_schedule.id, conference_id: conference.short_title
+        delete :destroy, params: { id: event_schedule.id, conference_id: conference.short_title }
       end
 
       it 'deletes the event schedule' do
-        expect{ destroy_action }.to change { EventSchedule.count }.by(-1)
+        expect { destroy_action }.to change { EventSchedule.count }.by(-1)
       end
 
       it 'has 200 status code' do
diff --git a/spec/controllers/admin/events_controller_spec.rb b/spec/controllers/admin/events_controller_spec.rb
index 682defce..b87f0a14 100644
--- a/spec/controllers/admin/events_controller_spec.rb
+++ b/spec/controllers/admin/events_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::EventsController do
@@ -16,7 +18,7 @@ describe Admin::EventsController do
     describe 'GET #show' do
       before :each do
         sign_in(organizer)
-        get :show, id: event_without_commercial.id, conference_id: conference.short_title
+        get :show, params: { id: event_without_commercial.id, conference_id: conference.short_title }
       end
 
       it 'assigns versions' do
diff --git a/spec/controllers/admin/organizations_controller_spec.rb b/spec/controllers/admin/organizations_controller_spec.rb
index 801cce83..3be8d50e 100644
--- a/spec/controllers/admin/organizations_controller_spec.rb
+++ b/spec/controllers/admin/organizations_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::OrganizationsController do
@@ -35,13 +37,13 @@ describe Admin::OrganizationsController do
     describe 'POST #create' do
       it 'does not create new organization' do
         expected = expect do
-          post :create, organization: attributes_for(:organization)
+          post :create, params: { organization: attributes_for(:organization) }
         end
         expected.to_not change(Organization, :count)
       end
 
       it 'redirects to root' do
-        post :create, organization: attributes_for(:organization)
+        post :create, params: { organization: attributes_for(:organization) }
 
         expect(flash[:alert]).to eq('You are not authorized to access this page.')
         expect(response).to redirect_to(root_path)
@@ -51,7 +53,7 @@ describe Admin::OrganizationsController do
     describe 'PATCH #update' do
       it 'does not update and redirects to root' do
         old_name = organization.name
-        patch :update, id: organization.id, organization: attributes_for(:organization, name: 'new name')
+        patch :update, params: { id: organization.id, organization: attributes_for(:organization, name: 'new name') }
 
         organization.reload
         expect(organization.name).to eq(old_name)
@@ -64,13 +66,13 @@ describe Admin::OrganizationsController do
       context 'for a valid organization' do
         it 'does not destroy a resource' do
           expected = expect do
-            delete :destroy, id: organization.id
+            delete :destroy, params: { id: organization.id }
           end
           expected.to_not change(Organization, :count)
         end
 
         it 'redirects to root' do
-          delete :destroy, id: organization.id
+          delete :destroy, params: { id: organization.id }
 
           expect(flash[:alert]).to eq('You are not authorized to access this page.')
           expect(response).to redirect_to(root_path)
@@ -102,13 +104,13 @@ describe Admin::OrganizationsController do
       context 'with valid attributes' do
         it 'creates new organization' do
           expected = expect do
-            post :create, organization: attributes_for(:organization)
+            post :create, params: { organization: attributes_for(:organization) }
           end
           expected.to change { Organization.count }.by(1)
         end
 
         it 'redirects to index' do
-          post :create, organization: attributes_for(:organization)
+          post :create, params: { organization: attributes_for(:organization) }
 
           expect(flash[:notice]).to eq('Organization successfully created')
           expect(response).to redirect_to(admin_organizations_path)
@@ -118,13 +120,13 @@ describe Admin::OrganizationsController do
       context 'with invalid attributes' do
         it 'does not create new organization' do
           expected = expect do
-            post :create, organization: attributes_for(:organization, name: '')
+            post :create, params: { organization: attributes_for(:organization, name: '') }
           end
           expected.to_not change(Organization, :count)
         end
 
         it 'redirects to new' do
-          post :create, organization: attributes_for(:organization, name: '')
+          post :create, params: { organization: attributes_for(:organization, name: '') }
 
           expect(flash[:error]).to eq("Name can't be blank")
           expect(response).to redirect_to(new_admin_organization_path)
@@ -134,7 +136,7 @@ describe Admin::OrganizationsController do
 
     describe 'PATCH #update' do
       it 'saves and redirects to index when the attributes are valid' do
-        patch :update, id: organization.id, organization: attributes_for(:organization, name: 'changed name')
+        patch :update, params: { id: organization.id, organization: attributes_for(:organization, name: 'changed name') }
 
         organization.reload
         expect(organization.name).to eq('changed name')
@@ -143,7 +145,7 @@ describe Admin::OrganizationsController do
       end
 
       it 'redirects to edit when attributes are invalid' do
-        patch :update, id: organization.id, organization: attributes_for(:organization, name: '')
+        patch :update, params: { id: organization.id, organization: attributes_for(:organization, name: '') }
 
         expect(flash[:error]).to eq("Name can't be blank")
         expect(response).to redirect_to(edit_admin_organization_path(organization))
@@ -154,13 +156,13 @@ describe Admin::OrganizationsController do
       context 'for a valid organization' do
         it 'should successfully destroy a resource' do
           expected = expect do
-            delete :destroy, id: organization.id
+            delete :destroy, params: { id: organization.id }
           end
           expected.to change { Organization.count }.by(-1)
         end
 
         it 'redirects to index' do
-          delete :destroy, id: organization.id
+          delete :destroy, params: { id: organization.id }
 
           expect(flash[:notice]).to eq('Organization successfully destroyed')
           expect(response).to redirect_to(admin_organizations_path)
@@ -172,8 +174,7 @@ describe Admin::OrganizationsController do
       let(:org_admin_role) { Role.find_by(name: 'organization_admin', resource: organization) }
 
       before do
-        post :assign_org_admins, id: organization.id,
-                                 user: { email: user.email }
+        post :assign_org_admins, params: { id: organization.id, user: { email: user.email } }
       end
 
       it 'assigns organization_admin role' do
@@ -186,8 +187,7 @@ describe Admin::OrganizationsController do
       let!(:org_admin_user) { create(:user, role_ids: [org_admin_role.id]) }
 
       before do
-        delete :unassign_org_admins, id: organization.id,
-                                     user: { email: org_admin_user.email }
+        delete :unassign_org_admins, params: { id: organization.id, user: { email: org_admin_user.email } }
       end
 
       it 'unassigns organization_admin role' do
diff --git a/spec/controllers/admin/programs_controller_spec.rb b/spec/controllers/admin/programs_controller_spec.rb
index 3ad98071..da739eed 100644
--- a/spec/controllers/admin/programs_controller_spec.rb
+++ b/spec/controllers/admin/programs_controller_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::ProgramsController, type: :controller do
-
   # It is necessary to use bang version of let to build roles before user
   let(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -10,7 +11,7 @@ describe Admin::ProgramsController, type: :controller do
   context 'not logged in user' do
     describe 'GET #show' do
       it 'does not render admin/programs#show' do
-        get :show, conference_id: conference.short_title
+        get :show, params: { conference_id: conference.short_title }
         expect(response).to redirect_to(user_session_path)
       end
     end
@@ -23,7 +24,7 @@ describe Admin::ProgramsController, type: :controller do
 
     describe 'PATCH #update' do
       it 'redirects to admin/programs#index' do
-        patch :update, conference_id: conference.short_title, program: attributes_for(:program)
+        patch :update, params: { conference_id: conference.short_title, program: attributes_for(:program) }
         conference.program.reload
         expect(response).to redirect_to admin_conference_program_path(conference.short_title)
       end
diff --git a/spec/controllers/admin/registration_periods_controller_spec.rb b/spec/controllers/admin/registration_periods_controller_spec.rb
index fd98ce77..4620c6b9 100644
--- a/spec/controllers/admin/registration_periods_controller_spec.rb
+++ b/spec/controllers/admin/registration_periods_controller_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::RegistrationPeriodsController do
-
   # It is necessary to use bang version of let to build roles before user
   let(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -11,35 +12,33 @@ describe Admin::RegistrationPeriodsController do
   let(:participant) { create(:user) }
 
   shared_examples 'access as administration or organizer' do
-
     before do
       conference.registration_period = create(:registration_period)
     end
 
     describe 'PATCH #update' do
-
       context 'valid attributes' do
-
         it 'locates the requested registration period object' do
-          patch :update, conference_id: conference.short_title, registration_period: attributes_for(:registration_period)
+          patch :update, params: { conference_id: conference.short_title, registration_period: attributes_for(:registration_period) }
           expect(assigns(:registration_period)).to eq(conference.registration_period)
         end
 
         it 'changes registration period attributes' do
           the_date = conference.end_date - 10
-          patch :update, conference_id: conference.short_title, registration_period:
-              attributes_for(:registration_period, start_date: the_date)
+          patch :update, params: { conference_id: conference.short_title, registration_period:
+              attributes_for(:registration_period, start_date: the_date) }
 
           conference.reload
           expect(conference.registration_period.start_date.to_s).to eq(the_date.to_s)
         end
 
         it 'redirects to the updated registration period' do
-          patch :update, conference_id: conference.short_title, registration_period:
-              attributes_for(:registration_period)
+          patch :update, params: { conference_id: conference.short_title, registration_period:
+              attributes_for(:registration_period) }
           conference.reload
           expect(response).to redirect_to admin_conference_registration_period_path(
-                                              conference.short_title)
+            conference.short_title
+          )
         end
 
         it 'sends email notification on conference registration date update' do
@@ -50,10 +49,10 @@ describe Admin::RegistrationPeriodsController do
                                                   start_date: Date.today,
                                                   end_date: Date.today + 2.days)
 
-          patch :update, conference_id: conference.short_title, registration_period:
+          patch :update, params: { conference_id: conference.short_title, registration_period:
               attributes_for(:registration_period,
                              start_date: Date.today + 2.days,
-                             end_date: Date.today + 4.days)
+                             end_date: Date.today + 4.days) }
           conference.reload
           allow(Mailbot).to receive(:conference_registration_date_update_mail).and_return(mailer)
         end
@@ -64,41 +63,34 @@ describe Admin::RegistrationPeriodsController do
       context 'with valid attributes' do
         it 'saves the registration period to the database' do
           expected = expect do
-            post :create,
-                 conference_id: conference.short_title,
-                 registration_period: attributes_for(:registration_period)
+            post :create, params: { conference_id: conference.short_title, registration_period: attributes_for(:registration_period) }
           end
           expected.to change { RegistrationPeriod.count }.by 1
         end
 
         it 'redirects to registration_periods#show' do
-          post :create,
-               conference_id: conference.short_title,
-               registration_period: attributes_for(:registration_period)
+          post :create, params: { conference_id: conference.short_title, registration_period: attributes_for(:registration_period) }
 
           expect(response).to redirect_to admin_conference_registration_period_path(
-                                              assigns[:conference].short_title)
+            assigns[:conference].short_title
+          )
         end
       end
 
       context 'with invalid attributes' do
         it 'does not save the registration period to the database' do
           expected = expect do
-            post :create,
-                 conference_id: conference.short_title,
-                 registration_period: attributes_for(:registration_period,
-                                                     start_date: nil,
-                                                     end_date: nil)
+            post :create, params: { conference_id: conference.short_title, registration_period: attributes_for(:registration_period,
+                                                                                                               start_date: nil,
+                                                                                                               end_date: nil) }
           end
           expected.to_not change { Conference.count }
         end
 
         it 're-renders the new template' do
-          post :create,
-               conference_id: conference.short_title,
-               registration_period: attributes_for(:registration_period,
-                                                   start_date: nil,
-                                                   end_date: nil)
+          post :create, params: { conference_id: conference.short_title, registration_period: attributes_for(:registration_period,
+                                                                                                             start_date: nil,
+                                                                                                             end_date: nil) }
           expect(response).to be_success
         end
       end
@@ -106,58 +98,56 @@ describe Admin::RegistrationPeriodsController do
 
     describe 'GET #edit' do
       it 'assigns the requested registration period to @registration_period' do
-        get :edit, conference_id: conference.short_title
+        get :edit, params: { conference_id: conference.short_title }
         expect(assigns(:registration_period)).to eq conference.registration_period
       end
 
       it 'renders the show template' do
-        get :edit, conference_id: conference.short_title
+        get :edit, params: { conference_id: conference.short_title }
         expect(response).to render_template :edit
       end
     end
 
     describe 'GET #show' do
       it 'assigns the requested registration period to @registration_period' do
-        get :show, conference_id: conference.short_title
+        get :show, params: { conference_id: conference.short_title }
         expect(assigns(:registration_period)).to eq conference.registration_period
       end
 
       it 'renders the show template' do
-        get :show, conference_id: conference.short_title
+        get :show, params: { conference_id: conference.short_title }
         expect(response).to render_template :show
       end
     end
 
     describe 'GET #new' do
       it 'assigns a new registration period to @registration_period' do
-        get :new, conference_id: conference.short_title
+        get :new, params: { conference_id: conference.short_title }
         expect(assigns(:registration_period)).to be_a_new(RegistrationPeriod)
       end
 
       it 'renders the :new template' do
-        get :new, conference_id: conference.short_title
+        get :new, params: { conference_id: conference.short_title }
         expect(response).to render_template :new
       end
     end
 
     describe 'DELETE #destroy' do
       it 'it deletes the registration period' do
-        expect { delete :destroy, conference_id: conference.short_title }.to change(RegistrationPeriod, :count).by(-1)
+        expect { delete :destroy, params: { conference_id: conference.short_title } }.to change(RegistrationPeriod, :count).by(-1)
       end
       it 'redirects to users#show' do
-        delete :destroy, conference_id: conference.short_title
+        delete :destroy, params: { conference_id: conference.short_title }
         expect(response).to redirect_to admin_conference_registration_period_path
       end
     end
   end
 
   describe 'organizer access' do
-
     before(:each) do
       sign_in(organizer)
     end
 
     it_behaves_like 'access as administration or organizer'
-
   end
 end
diff --git a/spec/controllers/admin/roles_controller_spec.rb b/spec/controllers/admin/roles_controller_spec.rb
index dcc81313..41f24ea3 100644
--- a/spec/controllers/admin/roles_controller_spec.rb
+++ b/spec/controllers/admin/roles_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::RolesController do
@@ -12,7 +14,7 @@ describe Admin::RolesController do
   describe 'GET #index' do
     before :each do
       sign_in(admin)
-      get :index, conference_id: conference.short_title
+      get :index, params: { conference_id: conference.short_title }
     end
 
     it 'assigns default value to selection variable' do
@@ -43,9 +45,7 @@ describe Admin::RolesController do
   describe 'PATCH #update' do
     before :each do
       sign_in admin
-      patch :update, conference_id: conference.short_title,
-                     id: 'cfp',
-                     role: { description: 'New description for cfp role!' }
+      patch :update, params: { conference_id: conference.short_title, id: 'cfp', role: { description: 'New description for cfp role!' } }
     end
 
     it 'changes the description of the role' do
@@ -56,9 +56,7 @@ describe Admin::RolesController do
   describe 'POST #toggle' do
     before :each do
       sign_in admin
-      post :toggle_user, conference_id: conference.short_title,
-                         user: { email: 'user1@osem.io' },
-                         id: 'cfp'
+      post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io' }, id: 'cfp' }
     end
 
     context 'assigns correct values to variables' do
@@ -77,17 +75,13 @@ describe Admin::RolesController do
 
     context 'adds role to user' do
       it 'adds second user' do
-        post :toggle_user, conference_id: conference.short_title,
-                           user: { email: 'user2@osem.io' },
-                           id: 'cfp'
+        post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user2@osem.io' }, id: 'cfp' }
 
         expect(user2.roles).to eq [cfp_role]
       end
 
       it 'assigns second role to user' do
-        post :toggle_user, conference_id: conference.short_title,
-                           user: { email: 'user1@osem.io' },
-                           id: 'organizer'
+        post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io' }, id: 'organizer' }
 
         expect(user1.roles).to eq [organizer_role, cfp_role]
       end
@@ -95,23 +89,17 @@ describe Admin::RolesController do
 
     context 'removes role from user' do
       it 'removes role from user' do
-        post :toggle_user, conference_id: conference.short_title,
-                           user: { email: 'user1@osem.io', state: 'false' },
-                           id: 'cfp'
+        post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io', state: 'false' }, id: 'cfp' }
 
         expect(user1.roles).to eq []
       end
 
       it 'removes second role from user' do
-        post :toggle_user, conference_id: conference.short_title,
-                           user: { email: 'user1@osem.io' },
-                           id: 'organizer'
+        post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io' }, id: 'organizer' }
 
         expect(user1.roles).to eq [organizer_role, cfp_role]
 
-        post :toggle_user, conference_id: conference.short_title,
-                           user: { email: 'user1@osem.io', state: 'false' },
-                           id: 'cfp'
+        post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io', state: 'false' }, id: 'cfp' }
 
         user1.reload
         expect(user1.roles).to eq [organizer_role]
@@ -120,15 +108,11 @@ describe Admin::RolesController do
 
     it 'does not remove role if user is the last organizer' do
       # Add role organizer
-      post :toggle_user, conference_id: conference.short_title,
-                         user: { email: 'user1@osem.io', state: 'true' },
-                         id: 'organizer'
+      post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io', state: 'true' }, id: 'organizer' }
       expect(organizer_role.users).to eq [user1]
 
       # Try to remove role organizer, when there is only 1 user as organizer
-      post :toggle_user, conference_id: conference.short_title,
-                         user: { email: 'user1@osem.io', state: 'false' },
-                         id: 'organizer'
+      post :toggle_user, params: { conference_id: conference.short_title, user: { email: 'user1@osem.io', state: 'false' }, id: 'organizer' }
       expect(organizer_role.users).to eq [user1]
     end
   end
diff --git a/spec/controllers/admin/rooms_controller_spec.rb b/spec/controllers/admin/rooms_controller_spec.rb
index dc8c3d2e..a4bf382f 100644
--- a/spec/controllers/admin/rooms_controller_spec.rb
+++ b/spec/controllers/admin/rooms_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::RoomsController do
@@ -10,7 +12,7 @@ describe Admin::RoomsController do
     before { sign_in admin }
 
     describe 'GET #index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'assigns conference, venue and rooms variables' do
         expect(assigns(:conference)).to eq conference
@@ -24,7 +26,7 @@ describe Admin::RoomsController do
     end
 
     describe 'GET #edit' do
-      before { get :edit, conference_id: conference.short_title, id: room.id }
+      before { get :edit, params: { conference_id: conference.short_title, id: room.id } }
 
       it 'renders edit template' do
         expect(response).to render_template('edit')
@@ -36,7 +38,7 @@ describe Admin::RoomsController do
     end
 
     describe 'GET #new' do
-      before { get :new, conference_id: conference.short_title }
+      before { get :new, params: { conference_id: conference.short_title } }
 
       it 'renders new template' do
         expect(response).to render_template('new')
@@ -50,7 +52,7 @@ describe Admin::RoomsController do
     describe 'POST #create' do
       context 'saves successfuly' do
         before do
-          post :create, room: attributes_for(:room), conference_id: conference.short_title
+          post :create, params: { room: attributes_for(:room), conference_id: conference.short_title }
         end
 
         it 'redirects to admin room index path' do
@@ -69,7 +71,7 @@ describe Admin::RoomsController do
       context 'save fails' do
         before do
           allow_any_instance_of(Room).to receive(:save).and_return(false)
-          post :create, room: attributes_for(:room), conference_id: conference.short_title
+          post :create, params: { room: attributes_for(:room), conference_id: conference.short_title }
         end
 
         it 'renders new template' do
@@ -89,9 +91,7 @@ describe Admin::RoomsController do
     describe 'PATCH #update' do
       context 'updates successfully' do
         before do
-          patch :update, room: attributes_for(:room, size: 2),
-                         conference_id: conference.short_title,
-                         id: room.id
+          patch :update, params: { room: attributes_for(:room, size: 2), conference_id: conference.short_title, id: room.id }
         end
 
         it 'redirects to admin room index path' do
@@ -111,9 +111,7 @@ describe Admin::RoomsController do
       context 'update fails' do
         before do
           allow_any_instance_of(Room).to receive(:save).and_return(false)
-          patch :update, room: attributes_for(:room, size: 2),
-                         conference_id: conference.short_title,
-                         id: room.id
+          patch :update, params: { room: attributes_for(:room, size: 2), conference_id: conference.short_title, id: room.id }
         end
 
         it 'renders edit template' do
@@ -133,7 +131,7 @@ describe Admin::RoomsController do
 
     describe 'DELETE #destroy' do
       context 'deletes successfully' do
-        before { delete :destroy, conference_id: conference.short_title, id: room.id }
+        before { delete :destroy, params: { conference_id: conference.short_title, id: room.id } }
 
         it 'redirects to admin room index path' do
           expect(response).to redirect_to admin_conference_venue_rooms_path(conference_id: conference.short_title)
@@ -151,7 +149,7 @@ describe Admin::RoomsController do
       context 'delete fails' do
         before do
           allow_any_instance_of(Room).to receive(:destroy).and_return(false)
-          delete :destroy, conference_id: conference.short_title, id: room.id
+          delete :destroy, params: { conference_id: conference.short_title, id: room.id }
         end
 
         it 'redirects to admin room index path' do
diff --git a/spec/controllers/admin/schedules_controller_spec.rb b/spec/controllers/admin/schedules_controller_spec.rb
index 7ba5860e..87bf19f4 100644
--- a/spec/controllers/admin/schedules_controller_spec.rb
+++ b/spec/controllers/admin/schedules_controller_spec.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::SchedulesController do
   let(:conference) { create(:conference) }
-  let(:schedule) { create(:schedule, program: conference.program)}
+  let(:schedule) { create(:schedule, program: conference.program) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let(:organizer) { create(:user, role_ids: organizer_role.id) }
 
@@ -14,27 +16,28 @@ describe Admin::SchedulesController do
 
     describe 'GET #index' do
       it 'renders the index template' do
-        get :index, conference_id: conference.short_title
+        get :index, params: { conference_id: conference.short_title }
         expect(response).to render_template :index
       end
     end
 
     describe 'POST #create' do
-      let(:create_action){ post :create, conference_id: conference.short_title }
+      let(:create_action) { post :create, params: { conference_id: conference.short_title } }
 
       it 'saves the schedule to the database' do
-        expect{ create_action }.to change { Schedule.count }.by 1
+        expect { create_action }.to change { Schedule.count }.by 1
       end
 
       it 'redirects to schedules#show' do
         create_action
         expect(response).to redirect_to admin_conference_schedule_path(
-                                        conference.short_title, assigns[:schedule])
+          conference.short_title, assigns[:schedule]
+        )
       end
     end
 
     describe 'GET #show' do
-      let(:show_action){ get :show, id: schedule.id, conference_id: conference.short_title }
+      let(:show_action) { get :show, params: { id: schedule.id, conference_id: conference.short_title } }
 
       it 'assigns the requested schedule to schedule' do
         show_action
@@ -48,10 +51,10 @@ describe Admin::SchedulesController do
     end
 
     describe 'DELETE #destroy' do
-      let(:destroy_action){ delete :destroy, id: schedule.id, conference_id: conference.short_title }
+      let(:destroy_action) { delete :destroy, params: { id: schedule.id, conference_id: conference.short_title } }
 
       it 'deletes the schedule' do
-        expect{ destroy_action }.to change { Schedule.count }.by(-1)
+        expect { destroy_action }.to change { Schedule.count }.by(-1)
       end
 
       it 'redirects to schedules#index' do
diff --git a/spec/controllers/admin/sponsorship_levels_controller_spec.rb b/spec/controllers/admin/sponsorship_levels_controller_spec.rb
index 058c703c..48fe03b4 100644
--- a/spec/controllers/admin/sponsorship_levels_controller_spec.rb
+++ b/spec/controllers/admin/sponsorship_levels_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::SponsorshipLevelsController do
@@ -9,7 +11,7 @@ describe Admin::SponsorshipLevelsController do
     before { sign_in admin }
 
     describe 'GET #index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'assigns conference and sponsorship_levels variables' do
         expect(assigns(:conference)).to eq conference
@@ -22,7 +24,7 @@ describe Admin::SponsorshipLevelsController do
     end
 
     describe 'GET #edit' do
-      before { get :edit, conference_id: conference.short_title, id: sponsorship_level.id }
+      before { get :edit, params: { conference_id: conference.short_title, id: sponsorship_level.id } }
 
       it 'renders edit template' do
         expect(response).to render_template('edit')
@@ -34,7 +36,7 @@ describe Admin::SponsorshipLevelsController do
     end
 
     describe 'GET #new' do
-      before { get :new, conference_id: conference.short_title }
+      before { get :new, params: { conference_id: conference.short_title } }
 
       it 'renders new template' do
         expect(response).to render_template('new')
@@ -48,8 +50,7 @@ describe Admin::SponsorshipLevelsController do
     describe 'POST #create' do
       context 'saves successfuly' do
         before(:each, run: true) do
-          post :create, sponsorship_level: attributes_for(:sponsorship_level),
-                        conference_id: conference.short_title
+          post :create, params: { sponsorship_level: attributes_for(:sponsorship_level), conference_id: conference.short_title }
         end
 
         it 'redirects to admin sponsorship_level index path', run: true do
@@ -62,17 +63,15 @@ describe Admin::SponsorshipLevelsController do
 
         it 'creates new sponsorship_level' do
           expect do
-            post :create, sponsorship_level: attributes_for(:sponsorship_level),
-                          conference_id: conference.short_title
-          end.to change{ conference.sponsorship_levels.count }.from(0).to(1)
+            post :create, params: { sponsorship_level: attributes_for(:sponsorship_level), conference_id: conference.short_title }
+          end.to change { conference.sponsorship_levels.count }.from(0).to(1)
         end
       end
 
       context 'save fails' do
         before do
           allow_any_instance_of(SponsorshipLevel).to receive(:save).and_return(false)
-          post :create, sponsorship_level: attributes_for(:sponsorship_level),
-                        conference_id: conference.short_title
+          post :create, params: { sponsorship_level: attributes_for(:sponsorship_level), conference_id: conference.short_title }
         end
 
         it 'renders new template' do
@@ -92,9 +91,7 @@ describe Admin::SponsorshipLevelsController do
     describe 'PATCH #update' do
       context 'updates successfully' do
         before do
-          patch :update, sponsorship_level: attributes_for(:sponsorship_level, title: 'Gold'),
-                         conference_id: conference.short_title,
-                         id: sponsorship_level.id
+          patch :update, params: { sponsorship_level: attributes_for(:sponsorship_level, title: 'Gold'), conference_id: conference.short_title, id: sponsorship_level.id }
         end
 
         it 'redirects to admin sponsorship_level index path' do
@@ -114,9 +111,7 @@ describe Admin::SponsorshipLevelsController do
       context 'update fails' do
         before do
           allow_any_instance_of(SponsorshipLevel).to receive(:save).and_return(false)
-          patch :update, sponsorship_level: attributes_for(:sponsorship_level, title: 'Gold'),
-                         conference_id: conference.short_title,
-                         id: sponsorship_level.id
+          patch :update, params: { sponsorship_level: attributes_for(:sponsorship_level, title: 'Gold'), conference_id: conference.short_title, id: sponsorship_level.id }
         end
 
         it 'renders edit template' do
@@ -137,7 +132,7 @@ describe Admin::SponsorshipLevelsController do
     describe 'DELETE #destroy' do
       context 'deletes successfully' do
         before(:each, run: true) do
-          delete :destroy, conference_id: conference.short_title, id: sponsorship_level.id
+          delete :destroy, params: { conference_id: conference.short_title, id: sponsorship_level.id }
         end
 
         it 'redirects to admin sponsorship_level index path', run: true do
@@ -151,15 +146,15 @@ describe Admin::SponsorshipLevelsController do
         it 'deletes the sponsorship_level' do
           sponsorship_level
           expect do
-            delete :destroy, conference_id: conference.short_title, id: sponsorship_level.id
-          end.to change{ conference.sponsorship_levels.count }.from(1).to(0)
+            delete :destroy, params: { conference_id: conference.short_title, id: sponsorship_level.id }
+          end.to change { conference.sponsorship_levels.count }.from(1).to(0)
         end
       end
 
       context 'delete fails' do
         before do
           allow_any_instance_of(SponsorshipLevel).to receive(:destroy).and_return(false)
-          delete :destroy, conference_id: conference.short_title, id: sponsorship_level.id
+          delete :destroy, params: { conference_id: conference.short_title, id: sponsorship_level.id }
         end
 
         it 'redirects to admin sponsorship_level index path' do
@@ -180,7 +175,7 @@ describe Admin::SponsorshipLevelsController do
       before do
         sponsorship_level
         @second_sponsorship_level = create(:sponsorship_level, conference: conference)
-        patch :up, conference_id: conference.short_title, id: @second_sponsorship_level.id
+        patch :up, params: { conference_id: conference.short_title, id: @second_sponsorship_level.id }
       end
 
       it 'moves sponsorship_level up by one position' do
@@ -195,7 +190,7 @@ describe Admin::SponsorshipLevelsController do
       before do
         sponsorship_level
         @second_sponsorship_level = create(:sponsorship_level, conference: conference)
-        patch :down, conference_id: conference.short_title, id: sponsorship_level.id
+        patch :down, params: { conference_id: conference.short_title, id: sponsorship_level.id }
       end
 
       it 'moves sponsorship_level down by one position' do
diff --git a/spec/controllers/admin/targets_controller_spec.rb b/spec/controllers/admin/targets_controller_spec.rb
index 2b8b5dd4..37c17e31 100644
--- a/spec/controllers/admin/targets_controller_spec.rb
+++ b/spec/controllers/admin/targets_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::TargetsController, type: :controller do
@@ -9,7 +11,7 @@ describe Admin::TargetsController, type: :controller do
     before { sign_in admin }
 
     describe 'GET #index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'renders index template' do
         expect(response).to render_template('index')
@@ -22,7 +24,7 @@ describe Admin::TargetsController, type: :controller do
     end
 
     describe 'GET #new' do
-      before { get :new, conference_id: conference.short_title }
+      before { get :new, params: { conference_id: conference.short_title } }
 
       it 'renders new template' do
         expect(response).to render_template('new')
@@ -36,7 +38,7 @@ describe Admin::TargetsController, type: :controller do
     describe 'POST #create' do
       context 'saves successfuly' do
         before do
-          post :create, target: attributes_for(:target), conference_id: conference.short_title
+          post :create, params: { target: attributes_for(:target), conference_id: conference.short_title }
         end
 
         it 'redirects to admin target index path' do
@@ -55,7 +57,7 @@ describe Admin::TargetsController, type: :controller do
       context 'save fails' do
         before do
           allow_any_instance_of(Target).to receive(:save).and_return(false)
-          post :create, target: attributes_for(:target), conference_id: conference.short_title
+          post :create, params: { target: attributes_for(:target), conference_id: conference.short_title }
         end
 
         it 'renders new template' do
@@ -73,7 +75,7 @@ describe Admin::TargetsController, type: :controller do
     end
 
     describe 'GET #edit' do
-      before { get :edit, conference_id: conference.short_title, id: target.id }
+      before { get :edit, params: { conference_id: conference.short_title, id: target.id } }
 
       it 'renders edit template' do
         expect(response).to render_template('edit')
@@ -87,9 +89,7 @@ describe Admin::TargetsController, type: :controller do
     describe 'PATCH #update' do
       context 'updates successfully' do
         before do
-          patch :update, target: attributes_for(:target, target_count: 2),
-                         conference_id: conference.short_title,
-                         id: target.id
+          patch :update, params: { target: attributes_for(:target, target_count: 2), conference_id: conference.short_title, id: target.id }
         end
 
         it 'redirects to admin target index path' do
@@ -109,9 +109,7 @@ describe Admin::TargetsController, type: :controller do
       context 'update fails' do
         before do
           allow_any_instance_of(Target).to receive(:save).and_return(false)
-          patch :update, target: attributes_for(:target, target_count: 2),
-                         conference_id: conference.short_title,
-                         id: target.id
+          patch :update, params: { target: attributes_for(:target, target_count: 2), conference_id: conference.short_title, id: target.id }
         end
 
         it 'renders edit template' do
@@ -130,7 +128,7 @@ describe Admin::TargetsController, type: :controller do
 
     describe 'DELETE #destroy' do
       context 'deletes successfully' do
-        before { delete :destroy, conference_id: conference.short_title, id: target.id }
+        before { delete :destroy, params: { conference_id: conference.short_title, id: target.id } }
 
         it 'redirects to admin target index path' do
           expect(response).to redirect_to admin_conference_targets_path(conference_id: conference.short_title)
@@ -148,7 +146,7 @@ describe Admin::TargetsController, type: :controller do
       context 'delete fails' do
         before do
           allow_any_instance_of(Target).to receive(:destroy).and_return(false)
-          delete :destroy, conference_id: conference.short_title, id: target.id
+          delete :destroy, params: { conference_id: conference.short_title, id: target.id }
         end
 
         it 'redirects to admin target index path' do
diff --git a/spec/controllers/admin/ticket_scannings_controller_spec.rb b/spec/controllers/admin/ticket_scannings_controller_spec.rb
index 2eb2e4ed..83909a28 100644
--- a/spec/controllers/admin/ticket_scannings_controller_spec.rb
+++ b/spec/controllers/admin/ticket_scannings_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::TicketScanningsController do
@@ -16,13 +18,13 @@ describe Admin::TicketScanningsController do
     describe 'POST #create' do
       it 'does not create new ticket scanning' do
         expected = expect do
-          post :create, physical_ticket_id: physical_ticket.token
+          post :create, params: { physical_ticket_id: physical_ticket.token }
         end
         expected.to_not change(TicketScanning, :count)
       end
 
       it 'redirects to root' do
-        post :create, physical_ticket_id: physical_ticket.token
+        post :create, params: { physical_ticket_id: physical_ticket.token }
         expect(flash[:alert]).to eq('You are not authorized to access this page.')
         expect(response).to redirect_to(root_path)
       end
@@ -37,13 +39,13 @@ describe Admin::TicketScanningsController do
       context 'with valid physical_ticket' do
         it 'creates new ticket scanning' do
           expected = expect do
-            post :create, physical_ticket_id: physical_ticket.token
+            post :create, params: { physical_ticket_id: physical_ticket.token }
           end
           expected.to change { TicketScanning.count }.by(1)
         end
 
         it 'redirects to index' do
-          post :create, physical_ticket_id: physical_ticket.token
+          post :create, params: { physical_ticket_id: physical_ticket.token }
           expect(flash[:notice]).to eq("Ticket with token #{physical_ticket.token} successfully scanned.")
           expect(response).to redirect_to(conferences_path)
         end
@@ -52,7 +54,7 @@ describe Admin::TicketScanningsController do
       context 'with Invalid physical_ticket' do
         it 'raises exception' do
           expected = expect do
-            post :create, physical_ticket_id: 'XXXX'
+            post :create, params: { physical_ticket_id: 'XXXX' }
           end
           expected.to raise_exception(ActiveRecord::RecordNotFound)
         end
diff --git a/spec/controllers/admin/tracks_controller_spec.rb b/spec/controllers/admin/tracks_controller_spec.rb
index 03511ce1..2fb6df8d 100644
--- a/spec/controllers/admin/tracks_controller_spec.rb
+++ b/spec/controllers/admin/tracks_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::TracksController do
@@ -15,7 +17,7 @@ describe Admin::TracksController do
 
   describe 'GET #index' do
     before :each do
-      get :index, conference_id: conference.short_title
+      get :index, params: { conference_id: conference.short_title }
     end
 
     it 'assigns @tracks with the correct values' do
@@ -31,7 +33,7 @@ describe Admin::TracksController do
 
   describe 'GET #show' do
     before :each do
-      get :show, conference_id: conference.short_title, id: track.short_name
+      get :show, params: { conference_id: conference.short_title, id: track.short_name }
     end
 
     it 'assigns the correct track' do
@@ -45,7 +47,7 @@ describe Admin::TracksController do
 
   describe 'GET #new' do
     before :each do
-      get :new, conference_id: conference.short_title
+      get :new, params: { conference_id: conference.short_title }
     end
 
     it 'assigns a new track with the correct conference' do
@@ -62,7 +64,7 @@ describe Admin::TracksController do
   describe 'POST #create' do
     context 'saves successfuly' do
       before :each do
-        post :create, track: attributes_for(:track), conference_id: conference.short_title
+        post :create, params: { track: attributes_for(:track), conference_id: conference.short_title }
       end
 
       it 'assigns a new track with the correct conference' do
@@ -92,7 +94,7 @@ describe Admin::TracksController do
     context 'save fails' do
       before :each do
         allow_any_instance_of(Track).to receive(:save).and_return(false)
-        post :create, track: attributes_for(:track, short_name: 'my_track'), conference_id: conference.short_title
+        post :create, params: { track: attributes_for(:track, short_name: 'my_track'), conference_id: conference.short_title }
       end
 
       it 'assigns a new track with the correct conference' do
@@ -117,7 +119,7 @@ describe Admin::TracksController do
 
   describe 'GET #edit' do
     before :each do
-      get :edit, conference_id: conference.short_title, id: track.short_name
+      get :edit, params: { conference_id: conference.short_title, id: track.short_name }
     end
 
     it 'assigns the correct track' do
@@ -132,9 +134,7 @@ describe Admin::TracksController do
   describe 'PATCH #update' do
     context 'updates successfully' do
       before :each do
-        patch :update, track: attributes_for(:track, color: '#FF0000'),
-                       conference_id: conference.short_title,
-                       id: track.short_name
+        patch :update, params: { track: attributes_for(:track, color: '#FF0000'), conference_id: conference.short_title, id: track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -158,9 +158,7 @@ describe Admin::TracksController do
     context 'update fails' do
       before :each do
         allow_any_instance_of(Track).to receive(:save).and_return(false)
-        patch :update, track: attributes_for(:track, color: '#FF0000'),
-                       conference_id: conference.short_title,
-                       id: track.short_name
+        patch :update, params: { track: attributes_for(:track, color: '#FF0000'), conference_id: conference.short_title, id: track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -185,7 +183,7 @@ describe Admin::TracksController do
   describe 'DELETE #destroy' do
     context 'deletes successfully' do
       before :each do
-        delete :destroy, conference_id: conference.short_title, id: track.short_name
+        delete :destroy, params: { conference_id: conference.short_title, id: track.short_name }
       end
 
       it 'redirects to admin tracks index path' do
@@ -204,7 +202,7 @@ describe Admin::TracksController do
     context 'delete fails' do
       before :each do
         allow_any_instance_of(Track).to receive(:destroy).and_return(false)
-        delete :destroy, conference_id: conference.short_title, id: track.short_name
+        delete :destroy, params: { conference_id: conference.short_title, id: track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -234,7 +232,7 @@ describe Admin::TracksController do
 
       context 'toggles successfully' do
         before :each do
-          patch :toggle_cfp_inclusion, conference_id: conference.short_title, id: self_organized_track.short_name, format: :js
+          patch :toggle_cfp_inclusion, params: { conference_id: conference.short_title, id: self_organized_track.short_name, format: :js }
           self_organized_track.reload
         end
 
@@ -254,7 +252,7 @@ describe Admin::TracksController do
       context 'save fails' do
         before :each do
           allow_any_instance_of(Track).to receive(:save).and_return(false)
-          patch :toggle_cfp_inclusion, conference_id: conference.short_title, id: self_organized_track.short_name, format: :js
+          patch :toggle_cfp_inclusion, params: { conference_id: conference.short_title, id: self_organized_track.short_name, format: :js }
           self_organized_track.reload
         end
 
@@ -280,7 +278,7 @@ describe Admin::TracksController do
 
       context 'toggles successfully' do
         before :each do
-          patch :toggle_cfp_inclusion, conference_id: conference.short_title, id: self_organized_track.short_name, format: :js
+          patch :toggle_cfp_inclusion, params: { conference_id: conference.short_title, id: self_organized_track.short_name, format: :js }
           self_organized_track.reload
         end
 
@@ -300,7 +298,7 @@ describe Admin::TracksController do
       context 'save fails' do
         before :each do
           allow_any_instance_of(Track).to receive(:save).and_return(false)
-          patch :toggle_cfp_inclusion, conference_id: conference.short_title, id: self_organized_track.short_name, format: :js
+          patch :toggle_cfp_inclusion, params: { conference_id: conference.short_title, id: self_organized_track.short_name, format: :js }
           self_organized_track.reload
         end
 
@@ -323,7 +321,7 @@ describe Admin::TracksController do
     before :each do
       self_organized_track.state = 'canceled'
       self_organized_track.save!
-      patch :restart, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :restart, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -342,7 +340,7 @@ describe Admin::TracksController do
 
   describe 'PATCH #to_accept' do
     before :each do
-      patch :to_accept, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :to_accept, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -362,7 +360,7 @@ describe Admin::TracksController do
   describe 'PATCH #accept' do
     shared_examples 'fails to accept' do
       before :each do
-        patch :accept, conference_id: conference.short_title, id: self_organized_track.short_name
+        patch :accept, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -380,7 +378,7 @@ describe Admin::TracksController do
 
     context 'has start_date, end_date and room' do
       before :each do
-        patch :accept, conference_id: conference.short_title, id: self_organized_track.short_name
+        patch :accept, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
         self_organized_track.reload
       end
 
@@ -470,7 +468,7 @@ describe Admin::TracksController do
     before :each do
       self_organized_track.state = 'accepted'
       self_organized_track.save!
-      patch :confirm, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :confirm, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -489,7 +487,7 @@ describe Admin::TracksController do
 
   describe 'PATCH #to_reject' do
     before :each do
-      patch :to_reject, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :to_reject, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -508,7 +506,7 @@ describe Admin::TracksController do
 
   describe 'PATCH #reject' do
     before :each do
-      patch :reject, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :reject, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -529,7 +527,7 @@ describe Admin::TracksController do
     before :each do
       self_organized_track.state = 'confirmed'
       self_organized_track.save!
-      patch :cancel, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :cancel, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
diff --git a/spec/controllers/admin/users_controller_spec.rb b/spec/controllers/admin/users_controller_spec.rb
index c0ba43ba..68e6d0c9 100644
--- a/spec/controllers/admin/users_controller_spec.rb
+++ b/spec/controllers/admin/users_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 describe Admin::UsersController do
   let(:admin) { create(:admin) }
@@ -21,12 +23,12 @@ describe Admin::UsersController do
   describe 'PATCH #toggle_confirmation' do
     it 'confirms user' do
       user_to_confirm = create(:user, email: 'unconfirmed_user@osem.io', confirmed_at: nil)
-      patch :toggle_confirmation, id: user_to_confirm.id, user: { to_confirm: 'true' }
+      patch :toggle_confirmation, params: { id: user_to_confirm.id, user: { to_confirm: 'true' } }
       user_to_confirm.reload
       expect(user_to_confirm.confirmed?).to eq true
     end
     it 'undo confirmation of user' do
-      patch :toggle_confirmation, id: user.id, user: { to_confirm: 'false' }
+      patch :toggle_confirmation, params: { id: user.id, user: { to_confirm: 'false' } }
       user.reload
       expect(user.confirmed?).to eq false
     end
@@ -34,7 +36,7 @@ describe Admin::UsersController do
   describe 'PATCH #update' do
     context 'valid attributes' do
       before :each do
-        patch :update, id: user.id, user: { name: 'new name', email: 'new_email@osem.io' }
+        patch :update, params: { id: user.id, user: { name: 'new name', email: 'new_email@osem.io' } }
       end
 
       it 'locates requested @user' do
@@ -42,8 +44,9 @@ describe Admin::UsersController do
       end
       it 'changes @users attributes' do
         expect(build(
-          :user, email: 'email_new@osem.io', id: user.id).email)
-              .to eq('email_new@osem.io')
+          :user, email: 'email_new@osem.io', id: user.id
+        ).email)
+          .to eq('email_new@osem.io')
       end
       it 'redirects to the updated user' do
         expect(response).to redirect_to admin_users_path
@@ -64,7 +67,7 @@ describe Admin::UsersController do
   describe 'POST #create' do
     context 'saves successfuly' do
       before do
-        post :create, user: attributes_for(:user)
+        post :create, params: { user: attributes_for(:user) }
       end
 
       it 'redirects to admin users index path' do
@@ -83,7 +86,7 @@ describe Admin::UsersController do
     context 'save fails' do
       before do
         allow_any_instance_of(User).to receive(:save).and_return(false)
-        post :create, user: attributes_for(:user)
+        post :create, params: { user: attributes_for(:user) }
       end
 
       it 'renders new template' do
@@ -96,8 +99,8 @@ describe Admin::UsersController do
 
       it 'does not create new user' do
         expect do
-          post :create, user: attributes_for(:user)
-        end.not_to change{ Event.count }
+          post :create, params: { user: attributes_for(:user) }
+        end.not_to change { Event.count }
       end
     end
   end
diff --git a/spec/controllers/admin/versions_controller_spec.rb b/spec/controllers/admin/versions_controller_spec.rb
index f04bc33d..3bfb315d 100644
--- a/spec/controllers/admin/versions_controller_spec.rb
+++ b/spec/controllers/admin/versions_controller_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Admin::VersionsController do
-
   let!(:conference) { create(:conference, short_title: 'exampletitle', description: 'Example Description') }
   let(:admin) { create(:admin) }
   let(:role_organizer) { conference.roles.find_by(name: 'organizer') }
@@ -15,8 +16,8 @@ describe Admin::VersionsController do
       end
 
       it 'reverts all changes for update actions' do
-        conference.update_attributes(short_title: 'testtitle', description: 'Some random text')
-        get :revert_object, id: PaperTrail::Version.last.id
+        conference.update(short_title: 'testtitle', description: 'Some random text')
+        get :revert_object, params: { id: PaperTrail::Version.last.id }
         conference.reload
         expect(conference.short_title).to eq 'exampletitle'
         expect(conference.description).to eq 'Example Description'
@@ -25,14 +26,14 @@ describe Admin::VersionsController do
       it 'shows correct flash on trying to revert create event of a deleted object' do
         creation_version_id = conference.program.event_types.first.versions.first.id
         conference.program.event_types.first.destroy
-        get :revert_object, id: creation_version_id
+        get :revert_object, params: { id: creation_version_id }
         expect(flash[:error]).to match('The item is already in the state that you are trying to revert it back to')
       end
 
       it 'reverting deletion of object  creates it again' do
         conference.program.event_types.first.destroy
         event_types_count = conference.program.event_types.count
-        get :revert_object, id: PaperTrail::Version.last.id
+        get :revert_object, params: { id: PaperTrail::Version.last.id }
         conference.reload
         expect(PaperTrail::Version.last.event).to eq 'create'
         expect(conference.program.event_types.count).to eq(event_types_count + 1)
@@ -40,14 +41,14 @@ describe Admin::VersionsController do
 
       it 'reverting creation of object deletes it ' do
         create(:lodging, conference: conference)
-        get :revert_object, id: PaperTrail::Version.last.id
+        get :revert_object, params: { id: PaperTrail::Version.last.id }
         expect(PaperTrail::Version.last.event).to eq 'destroy'
         expect(Lodging.count).to eq 0
       end
 
       it 'reverting creation of conference is not permitted' do
         conference_count_before = Conference.count
-        get :revert_object, id: conference.versions.first.id
+        get :revert_object, params: { id: conference.versions.first.id }
         expect(flash[:alert]).to eq 'You are not authorized to access this page.'
         expect(Conference.count).to eq(conference_count_before)
       end
@@ -59,40 +60,40 @@ describe Admin::VersionsController do
       end
 
       it 'reverts specified change for update actions' do
-        conference.update_attributes(short_title: 'testtitle', description: 'Some random text')
-        get :revert_attribute, id: PaperTrail::Version.last.id, attribute: 'short_title'
+        conference.update(short_title: 'testtitle', description: 'Some random text')
+        get :revert_attribute, params: { id: PaperTrail::Version.last.id, attribute: 'short_title' }
         conference.reload
         expect(conference.short_title).to eq 'exampletitle'
         expect(conference.description).to eq 'Some random text'
       end
 
       it 'shows correct flash on trying to revert to the current state' do
-        conference.update_attributes(short_title: 'testtitle', description: 'Some random text')
-        conference.update_attributes(short_title: 'exampletitle')
-        get :revert_attribute, id: PaperTrail::Version.all[-2].id, attribute: 'short_title'
+        conference.update(short_title: 'testtitle', description: 'Some random text')
+        conference.update(short_title: 'exampletitle')
+        get :revert_attribute, params: { id: PaperTrail::Version.all[-2].id, attribute: 'short_title' }
         expect(flash[:error]).to match('The item is already in the state that you are trying to revert it back to')
         expect(conference.short_title).to eq 'exampletitle'
       end
 
       it 'fails on trying to revert deleted object' do
-        conference.program.event_types.first.update_attributes(title: 'New Event Title')
+        conference.program.event_types.first.update(title: 'New Event Title')
         conference.program.event_types.first.destroy
-        get :revert_attribute, id: PaperTrail::Version.all[-2].id, attribute: 'title'
+        get :revert_attribute, params: { id: PaperTrail::Version.all[-2].id, attribute: 'title' }
         conference.reload
         expect(flash[:alert]).to eq 'You are not authorized to access this page.'
       end
 
       it 'fails on trying to revert creation event' do
         create(:lodging, conference: conference)
-        get :revert_attribute, id: PaperTrail::Version.last.id, attribute: 'name'
+        get :revert_attribute, params: { id: PaperTrail::Version.last.id, attribute: 'name' }
         expect(flash[:alert]).to eq 'You are not authorized to access this page.'
       end
 
       it 'revert fails when attribute is invalid' do
-        conference.update_attributes(short_title: 'testtitle', description: 'Some random text')
+        conference.update(short_title: 'testtitle', description: 'Some random text')
         before_conference_title = conference.title
         # Note: even though title is a valid attribute of conference, it was not updated in the change we are trying to revert
-        get :revert_attribute, id: PaperTrail::Version.last.id, attribute: 'title'
+        get :revert_attribute, params: { id: PaperTrail::Version.last.id, attribute: 'title' }
         conference.reload
         expect(conference.short_title).to eq 'testtitle'
         expect(conference.description).to eq 'Some random text'
@@ -105,7 +106,7 @@ describe Admin::VersionsController do
       it 'raises error if user is not of any role' do
         user = create(:user)
         sign_in user
-        get :index, conference_id: conference.short_title
+        get :index, params: { conference_id: conference.short_title }
         expect(flash[:alert]).to match('You are not authorized to access this page.')
       end
 
@@ -113,19 +114,19 @@ describe Admin::VersionsController do
         before :each do
           @user = create(:user)
 
-          conference.update_attributes(short_title: 'testtitle', description: 'Some random text')
+          conference.update(short_title: 'testtitle', description: 'Some random text')
           @version_organizer = PaperTrail::Version.last
           create(:cfp, program: conference.program)
           @version_cfp = PaperTrail::Version.last
           registration = create(:registration, conference: conference)
-          registration.update_attributes(attended: true)
+          registration.update(attended: true)
           @version_info_desk = PaperTrail::Version.last
         end
 
         it 'when user has role cfp' do
           @user.roles = [role_cfp]
           sign_in @user
-          get :index, conference_id: conference.short_title
+          get :index, params: { conference_id: conference.short_title }
 
           expect(assigns(:versions).include?(@version_cfp)).to eq true
           expect(assigns(:versions).include?(@version_organizer)).to eq false
@@ -134,7 +135,7 @@ describe Admin::VersionsController do
         it 'when user has role info_desk' do
           @user.roles = [role_info_desk]
           sign_in @user
-          get :index, conference_id: conference.short_title
+          get :index, params: { conference_id: conference.short_title }
 
           expect(assigns(:versions).include?(@version_info_desk)).to eq true
           expect(assigns(:versions).include?(@version_organizer)).to eq false
@@ -144,7 +145,7 @@ describe Admin::VersionsController do
         it 'when user has role organizer' do
           @user.roles = [role_organizer]
           sign_in @user
-          get :index, conference_id: conference.short_title
+          get :index, params: { conference_id: conference.short_title }
 
           expect(assigns(:versions).include?(@version_organizer)).to eq true
           expect(assigns(:versions).include?(@version_cfp)).to eq true
diff --git a/spec/controllers/api/v1/conferences_controller_spec.rb b/spec/controllers/api/v1/conferences_controller_spec.rb
index a64a1adc..6e819e99 100644
--- a/spec/controllers/api/v1/conferences_controller_spec.rb
+++ b/spec/controllers/api/v1/conferences_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Api::V1::ConferencesController do
@@ -26,7 +28,7 @@ describe Api::V1::ConferencesController do
 
   describe 'GET #show' do
     before(:each) do
-      get :show, id: 'conf_two', format: :json
+      get :show, params: { id: 'conf_two', format: :json }
       @json = JSON.parse(response.body)['conferences']
     end
 
diff --git a/spec/controllers/api/v1/events_controller_spec.rb b/spec/controllers/api/v1/events_controller_spec.rb
index daee0002..877451ce 100644
--- a/spec/controllers/api/v1/events_controller_spec.rb
+++ b/spec/controllers/api/v1/events_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Api::V1::EventsController do
@@ -8,7 +10,6 @@ describe Api::V1::EventsController do
   describe 'GET #index' do
     context 'without conference scope' do
       it 'returns all confirmed events' do
-
         get :index, format: :json
         json = JSON.parse(response.body)['events']
         expect(response).to be_success
@@ -21,8 +22,7 @@ describe Api::V1::EventsController do
 
     context 'with conference scope' do
       it 'returns all confirmed events of conference' do
-
-        get :index, conference_id: conference.short_title, format: :json
+        get :index, params: { conference_id: conference.short_title, format: :json }
         json = JSON.parse(response.body)['events']
 
         expect(response).to be_success
diff --git a/spec/controllers/api/v1/rooms_controller_spec.rb b/spec/controllers/api/v1/rooms_controller_spec.rb
index 48a8db98..5843c641 100644
--- a/spec/controllers/api/v1/rooms_controller_spec.rb
+++ b/spec/controllers/api/v1/rooms_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Api::V1::RoomsController do
@@ -9,7 +11,6 @@ describe Api::V1::RoomsController do
   describe 'GET #index' do
     context 'without conference scope' do
       it 'returns all rooms' do
-
         get :index, format: :json
         json = JSON.parse(response.body)['rooms']
 
@@ -23,8 +24,7 @@ describe Api::V1::RoomsController do
 
     context 'with conference scope' do
       it 'returns all rooms of conference' do
-
-        get :index, conference_id: conference.short_title, format: :json
+        get :index, params: { conference_id: conference.short_title, format: :json }
         json = JSON.parse(response.body)['rooms']
 
         expect(response).to be_success
diff --git a/spec/controllers/api/v1/speakers_controller_spec.rb b/spec/controllers/api/v1/speakers_controller_spec.rb
index 539baeaf..e51f4293 100644
--- a/spec/controllers/api/v1/speakers_controller_spec.rb
+++ b/spec/controllers/api/v1/speakers_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Api::V1::SpeakersController do
@@ -16,7 +18,6 @@ describe Api::V1::SpeakersController do
 
     context 'without conference scope' do
       it 'returns all speakers' do
-
         get :index, format: :json
         json = JSON.parse(response.body)['speakers']
         expect(response).to be_success
@@ -28,8 +29,7 @@ describe Api::V1::SpeakersController do
 
     context 'with conference scope' do
       it 'returns all speakers of conference' do
-
-        get :index, conference_id: conference.short_title, format: :json
+        get :index, params: { conference_id: conference.short_title, format: :json }
         json = JSON.parse(response.body)['speakers']
 
         expect(response).to be_success
diff --git a/spec/controllers/api/v1/tracks_controller_spec.rb b/spec/controllers/api/v1/tracks_controller_spec.rb
index a1424ce3..24ccf80d 100644
--- a/spec/controllers/api/v1/tracks_controller_spec.rb
+++ b/spec/controllers/api/v1/tracks_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Api::V1::TracksController do
@@ -8,7 +10,6 @@ describe Api::V1::TracksController do
   describe 'GET #index' do
     context 'without conference scope' do
       it 'returns all tracks' do
-
         get :index, format: :json
         json = JSON.parse(response.body)['tracks']
 
@@ -22,8 +23,7 @@ describe Api::V1::TracksController do
 
     context 'with conference scope' do
       it 'returns all rooms of conference' do
-
-        get :index, conference_id: conference.short_title, format: :json
+        get :index, params: { conference_id: conference.short_title, format: :json }
         json = JSON.parse(response.body)['tracks']
 
         expect(response).to be_success
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index 4d1c2eab..6f02a7c1 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -1,10 +1,11 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ApplicationController, type: :controller do
   let(:conference) { create(:conference) }
 
   describe 'user is signed in' do
-
     describe 'as admin' do
       let(:admin) { create(:admin) }
       before { sign_in(admin) }
@@ -31,16 +32,13 @@ describe ApplicationController, type: :controller do
         end
       end
     end
-
   end
-
 end
 
 describe ApplicationController, type: :request do
   let(:conference) { create(:conference) }
 
   describe 'Skylight link' do
-
     around do |example|
       original_value = ENV['SKYLIGHT_PUBLIC_DASHBOARD_URL']
       example.run
@@ -70,7 +68,5 @@ describe ApplicationController, type: :request do
         expect(response.body).to_not match(/skylight/i)
       end
     end
-
   end
-
 end
diff --git a/spec/controllers/booths_controller_spec.rb b/spec/controllers/booths_controller_spec.rb
index 56f3b9d9..55969416 100644
--- a/spec/controllers/booths_controller_spec.rb
+++ b/spec/controllers/booths_controller_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe BoothsController do
-
   let(:user) { create(:user) }
   let(:conference) { create(:conference) }
   let(:booth) { create(:booth, title: 'Title', conference: conference) }
@@ -13,7 +14,7 @@ describe BoothsController do
     end
 
     describe 'GET index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'assigns attributes for booths' do
         expect(assigns(:booths)).to eq([booth])
@@ -25,7 +26,7 @@ describe BoothsController do
     end
 
     describe 'GET #new' do
-      before { get :new, conference_id: conference.short_title }
+      before { get :new, params: { conference_id: conference.short_title } }
 
       it 'assigns attributes for booths' do
         expect(assigns(:booth)).to be_a_new(Booth)
@@ -38,7 +39,7 @@ describe BoothsController do
 
     describe 'POST #create' do
       context 'successfully created' do
-        before { post :create, booth: attributes_for(:booth), conference_id: conference.short_title }
+        before { post :create, params: { booth: attributes_for(:booth), conference_id: conference.short_title } }
 
         it 'creates a new booth' do
           expect(Booth.count).to_not eq(0)
@@ -58,11 +59,11 @@ describe BoothsController do
       end
 
       context 'create action fails' do
-        before { post :create, booth: attributes_for(:booth, title: ''), conference_id: conference.short_title }
+        before { post :create, params: { booth: attributes_for(:booth, title: ''), conference_id: conference.short_title } }
 
         it 'does not create any record' do
           expected = expect do
-            post :create, booth: attributes_for(:booth, title: ''), conference_id: conference.short_title
+            post :create, params: { booth: attributes_for(:booth, title: ''), conference_id: conference.short_title }
           end
           expected.to_not change(Booth, :count)
         end
@@ -78,7 +79,7 @@ describe BoothsController do
     end
 
     describe 'GET #edit' do
-      before { get :edit, id: booth.id, conference_id: conference.short_title }
+      before { get :edit, params: { id: booth.id, conference_id: conference.short_title } }
 
       it 'renders edit template' do
         expect(response).to render_template('edit')
@@ -91,7 +92,7 @@ describe BoothsController do
 
     describe 'PATCH #update' do
       context 'updates suchessfully' do
-        before { patch :update, id: booth.id, booth: attributes_for(:booth, title: 'different'), conference_id: conference.short_title }
+        before { patch :update, params: { id: booth.id, booth: attributes_for(:booth, title: 'different'), conference_id: conference.short_title } }
 
         it 'redirects to booth index path' do
           expect(response).to redirect_to conference_booths_path
diff --git a/spec/controllers/conference_registration_controller_spec.rb b/spec/controllers/conference_registration_controller_spec.rb
index a6f1503c..20a13b28 100644
--- a/spec/controllers/conference_registration_controller_spec.rb
+++ b/spec/controllers/conference_registration_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ConferenceRegistrationsController, type: :controller do
@@ -11,7 +13,7 @@ describe ConferenceRegistrationsController, type: :controller do
     before :each do
       sign_in send(user) if user
       stub_const('ENV', ENV.to_hash.merge('OSEM_ICHAIN_ENABLED' => ichain))
-      get :new, conference_id: conference.short_title
+      get :new, params: { conference_id: conference.short_title }
     end
 
     it 'redirects' do
@@ -27,7 +29,7 @@ describe ConferenceRegistrationsController, type: :controller do
     before :each do
       sign_in send(user) if user
       stub_const('ENV', ENV.to_hash.merge('OSEM_ICHAIN_ENABLED' => ichain))
-      get :new, conference_id: conference.short_title
+      get :new, params: { conference_id: conference.short_title }
     end
 
     it 'user variable exists' do
@@ -229,7 +231,7 @@ describe ConferenceRegistrationsController, type: :controller do
 
       context 'successful request' do
         before do
-          get :show, conference_id: conference.short_title
+          get :show, params: { conference_id: conference.short_title }
         end
 
         it 'assigns variables' do
@@ -248,7 +250,7 @@ describe ConferenceRegistrationsController, type: :controller do
           @purchased_ticket = create(:ticket_purchase, conference: conference,
                                                        user: user,
                                                        ticket: @ticket)
-          get :show, conference_id: conference.short_title
+          get :show, params: { conference_id: conference.short_title }
         end
 
         it 'does not assign price of purchased tickets to total_price and purchased tickets to tickets without payment' do
@@ -258,7 +260,7 @@ describe ConferenceRegistrationsController, type: :controller do
 
       context 'user has not purchased any ticket' do
         before do
-          get :show, conference_id: conference.short_title
+          get :show, params: { conference_id: conference.short_title }
         end
 
         it 'assigns 0 dollars to total_price and empty array to tickets variables' do
@@ -271,7 +273,7 @@ describe ConferenceRegistrationsController, type: :controller do
     describe 'GET #edit' do
       before do
         @registration = create(:registration, conference: conference, user: user)
-        get :edit, conference_id: conference.short_title
+        get :edit, params: { conference_id: conference.short_title }
       end
 
       it 'assigns conference and registration variable' do
@@ -289,13 +291,12 @@ describe ConferenceRegistrationsController, type: :controller do
         @registration = create(:registration,
                                conference: conference,
                                user: user,
-                               arrival: Date.new(2014, 04, 25))
+                               arrival: Date.new(2014, 0o4, 25))
       end
 
       context 'updates successfully' do
         before do
-          patch :update, registration: attributes_for(:registration, arrival: Date.new(2014, 04, 29)),
-                         conference_id: conference.short_title
+          patch :update, params: { registration: attributes_for(:registration, arrival: Date.new(2014, 0o4, 29)), conference_id: conference.short_title }
         end
 
         it 'redirects to registration show path' do
@@ -308,15 +309,14 @@ describe ConferenceRegistrationsController, type: :controller do
 
         it 'updates the registration' do
           @registration.reload
-          expect(@registration.arrival).to eq Date.new(2014, 04, 29)
+          expect(@registration.arrival).to eq Date.new(2014, 0o4, 29)
         end
       end
 
       context 'update fails' do
         before do
           allow_any_instance_of(Registration).to receive(:update_attributes).and_return(false)
-          patch :update, registration: attributes_for(:registration, arrival: Date.new(2014, 04, 27)),
-                         conference_id: conference.short_title
+          patch :update, params: { registration: attributes_for(:registration, arrival: Date.new(2014, 0o4, 27)), conference_id: conference.short_title }
         end
 
         it 'renders edit template' do
@@ -329,7 +329,7 @@ describe ConferenceRegistrationsController, type: :controller do
 
         it 'does not update the registration' do
           @registration.reload
-          expect(@registration.arrival).to eq Date.new(2014, 04, 25)
+          expect(@registration.arrival).to eq Date.new(2014, 0o4, 25)
         end
       end
     end
@@ -341,7 +341,7 @@ describe ConferenceRegistrationsController, type: :controller do
 
       context 'deletes successfully' do
         before(:each, run: true) do
-          delete :destroy, conference_id: conference.short_title
+          delete :destroy, params: { conference_id: conference.short_title }
         end
 
         it 'redirects to root path', run: true do
@@ -354,15 +354,15 @@ describe ConferenceRegistrationsController, type: :controller do
 
         it 'deletes the registration' do
           expect do
-            delete :destroy, conference_id: conference.short_title
-          end.to change{ Registration.count }.from(2).to(1)
+            delete :destroy, params: { conference_id: conference.short_title }
+          end.to change { Registration.count }.from(2).to(1)
         end
       end
 
       context 'delete fails' do
         before do
           allow_any_instance_of(Registration).to receive(:destroy).and_return(false)
-          delete :destroy, conference_id: conference.short_title
+          delete :destroy, params: { conference_id: conference.short_title }
         end
 
         it 'redirects to registration show path' do
diff --git a/spec/controllers/conferences_controller_spec.rb b/spec/controllers/conferences_controller_spec.rb
index cdbebf9f..de0fe32f 100644
--- a/spec/controllers/conferences_controller_spec.rb
+++ b/spec/controllers/conferences_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ConferencesController do
@@ -15,12 +17,12 @@ describe ConferencesController do
   describe 'GET #show' do
     context 'conference made public' do
       it 'assigns the requested conference to conference' do
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(assigns(:conference)).to eq conference
       end
 
       it 'renders the show template' do
-        get :show, id: conference.short_title
+        get :show, params: { id: conference.short_title }
         expect(response).to render_template :show
       end
     end
@@ -46,5 +48,4 @@ describe ConferencesController do
       expect(response.response_code).to eq(200)
     end
   end
-
 end
diff --git a/spec/controllers/confirmations_controller_spec.rb b/spec/controllers/confirmations_controller_spec.rb
index 1db675b3..60675d47 100644
--- a/spec/controllers/confirmations_controller_spec.rb
+++ b/spec/controllers/confirmations_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ConfirmationsController do
@@ -9,7 +11,7 @@ describe ConfirmationsController do
 
   context 'user is not signed in' do
     it 'confirms and signs in user' do
-      get :show, confirmation_token: user.confirmation_token
+      get :show, params: { confirmation_token: user.confirmation_token }
       user.reload
       expect(user.confirmed?).to eq true
       expect(controller.current_user).to eq user
@@ -20,7 +22,7 @@ describe ConfirmationsController do
     before { sign_in user }
 
     it 'confirms user' do
-      get :show, confirmation_token: user.confirmation_token
+      get :show, params: { confirmation_token: user.confirmation_token }
       user.reload
       expect(user.confirmed?).to eq true
     end
diff --git a/spec/controllers/organizations_controller_spec.rb b/spec/controllers/organizations_controller_spec.rb
index eb0109a1..e719f823 100644
--- a/spec/controllers/organizations_controller_spec.rb
+++ b/spec/controllers/organizations_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe OrganizationsController do
@@ -35,7 +37,7 @@ describe OrganizationsController do
 
   describe 'GET #conferences' do
     before :each do
-      get :conferences, id: organization.id
+      get :conferences, params: { id: organization.id }
     end
 
     it 'loads the organization' do
diff --git a/spec/controllers/physical_ticket_controller_spec.rb b/spec/controllers/physical_ticket_controller_spec.rb
index 476a1717..7b2a02c4 100644
--- a/spec/controllers/physical_ticket_controller_spec.rb
+++ b/spec/controllers/physical_ticket_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe PhysicalTicketsController do
@@ -9,7 +11,7 @@ describe PhysicalTicketsController do
   describe 'GET #show' do
     before :each do
       sign_in user
-      get :show, id: physical_ticket.token, conference_id: conference.short_title
+      get :show, params: { id: physical_ticket.token, conference_id: conference.short_title }
     end
 
     it 'assigns ticket_layout' do
diff --git a/spec/controllers/proposals_controller_spec.rb b/spec/controllers/proposals_controller_spec.rb
index 9b01e55f..5177d784 100644
--- a/spec/controllers/proposals_controller_spec.rb
+++ b/spec/controllers/proposals_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ProposalsController do
@@ -11,7 +13,7 @@ describe ProposalsController do
       before do
         # We allow new proposal only if program has open cfp
         create(:cfp, program: conference.program)
-        get :new, conference_id: conference.short_title
+        get :new, params: { conference_id: conference.short_title }
       end
 
       it 'assigns user and url variables' do
@@ -29,9 +31,7 @@ describe ProposalsController do
       before { create(:cfp, program: conference.program) }
 
       it 'assigns url variables' do
-        post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                      conference_id: conference.short_title,
-                      user: attributes_for(:user)
+        post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
         expect(assigns(:url)).to eq '/conferences/lama101/program/proposals'
       end
 
@@ -39,9 +39,7 @@ describe ProposalsController do
         describe 'user related actions' do
           before do
             @new_user = attributes_for(:user)
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: @new_user
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: @new_user }
           end
 
           it 'creates new user' do
@@ -56,9 +54,7 @@ describe ProposalsController do
         context 'creates proposal successfully' do
           before(:each, run: true) do
             @new_user = attributes_for(:user)
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: @new_user
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: @new_user }
           end
 
           it 'assigns event variable', run: true do
@@ -84,19 +80,15 @@ describe ProposalsController do
 
           it 'creates new event' do
             expect do
-              post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                            conference_id: conference.short_title,
-                            user: attributes_for(:user)
-            end.to change{ Event.count }.by 1
+              post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
+            end.to change { Event.count }.by 1
           end
         end
 
         context 'proposal save fails' do
           before(:each, run: true) do
             allow_any_instance_of(Event).to receive(:save).and_return(false)
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: attributes_for(:user)
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
           end
 
           it 'renders new template', run: true do
@@ -110,10 +102,8 @@ describe ProposalsController do
           it 'does not create new proposal' do
             allow_any_instance_of(Event).to receive(:save).and_return(false)
             expect do
-              post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                            conference_id: conference.short_title,
-                            user: attributes_for(:user)
-            end.not_to change{ Event.count }
+              post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
+            end.not_to change { Event.count }
           end
         end
       end
@@ -123,25 +113,19 @@ describe ProposalsController do
 
         it 'does not create new user' do
           expect do
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: attributes_for(:user)
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
           end.not_to change { User.count }
         end
 
         it 'does not create new event' do
           expect do
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: attributes_for(:user)
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
           end.not_to change { Event.count }
         end
 
         describe 'response' do
           before do
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title,
-                          user: attributes_for(:user)
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title, user: attributes_for(:user) }
           end
 
           it 'renders new template' do
@@ -162,7 +146,7 @@ describe ProposalsController do
     end
 
     describe 'GET #index' do
-      before { get :index, conference_id: conference.short_title }
+      before { get :index, params: { conference_id: conference.short_title } }
 
       it 'assigns conference, program and events variables' do
         expect(assigns(:conference)).to eq conference
@@ -177,7 +161,7 @@ describe ProposalsController do
 
     describe 'GET #show' do
       before do
-        get :show, conference_id: conference.short_title, id: event.id
+        get :show, params: { conference_id: conference.short_title, id: event.id }
       end
 
       it 'assigns event variable' do
@@ -193,7 +177,7 @@ describe ProposalsController do
       before do
         # We allow new proposal only if program has open cfp
         create(:cfp, program: conference.program)
-        get :new, conference_id: conference.short_title
+        get :new, params: { conference_id: conference.short_title }
       end
 
       it 'assigns user and url variables' do
@@ -208,7 +192,7 @@ describe ProposalsController do
 
     describe 'GET #edit' do
       before do
-        get :edit, conference_id: conference.short_title, id: event.id
+        get :edit, params: { conference_id: conference.short_title, id: event.id }
       end
 
       it 'assigns event and url variables' do
@@ -226,15 +210,13 @@ describe ProposalsController do
       before { create(:cfp, program: conference.program) }
 
       it 'assigns url variables' do
-        post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                      conference_id: conference.short_title
+        post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title }
         expect(assigns(:url)).to eq '/conferences/lama101/program/proposals'
       end
 
       context 'creates proposal successfully' do
         before(:each, run: true) do
-          post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                        conference_id: conference.short_title
+          post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title }
         end
 
         it 'assigns event variable', run: true do
@@ -260,17 +242,15 @@ describe ProposalsController do
 
         it 'creates new event' do
           expect do
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title
-          end.to change{ Event.count }.by 1
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title }
+          end.to change { Event.count }.by 1
         end
       end
 
       context 'proposal save fails' do
         before(:each, run: true) do
           allow_any_instance_of(Event).to receive(:save).and_return(false)
-          post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                        conference_id: conference.short_title
+          post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title }
         end
 
         it 'renders new template', run: true do
@@ -284,27 +264,21 @@ describe ProposalsController do
         it 'does not create new proposal' do
           allow_any_instance_of(Event).to receive(:save).and_return(false)
           expect do
-            post :create, event: attributes_for(:event, event_type_id: event_type.id),
-                          conference_id: conference.short_title
-          end.not_to change{ Event.count }
+            post :create, params: { event: attributes_for(:event, event_type_id: event_type.id), conference_id: conference.short_title }
+          end.not_to change { Event.count }
         end
       end
     end
 
     describe 'PATCH #update' do
-
       it 'assigns url variable' do
-        patch :update, event: attributes_for(:event, title: 'some title', event_type_id: event_type.id),
-                       conference_id: conference.short_title,
-                       id: event.id
+        patch :update, params: { event: attributes_for(:event, title: 'some title', event_type_id: event_type.id), conference_id: conference.short_title, id: event.id }
         expect(assigns(:url)).to eq "/conferences/lama101/program/proposals/#{event.id}"
       end
 
       context 'updates successfully' do
         before do
-          patch :update, event: attributes_for(:event, title: 'some title', event_type_id: event_type.id),
-                         conference_id: conference.short_title,
-                         id: event.id
+          patch :update, params: { event: attributes_for(:event, title: 'some title', event_type_id: event_type.id), conference_id: conference.short_title, id: event.id }
         end
 
         it 'updates the proposal' do
@@ -324,9 +298,7 @@ describe ProposalsController do
       context 'update fails' do
         before do
           allow_any_instance_of(Event).to receive(:save).and_return(false)
-          patch :update, event: attributes_for(:event, title: 'some title', event_type_id: event_type.id),
-                         conference_id: conference.short_title,
-                         id: event.id
+          patch :update, params: { event: attributes_for(:event, title: 'some title', event_type_id: event_type.id), conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not update the proposal' do
@@ -345,15 +317,14 @@ describe ProposalsController do
     end
 
     describe 'PATCH #withdraw' do
-
       it 'assigns url variable' do
-        patch :withdraw, conference_id: conference.short_title, id: event.id
+        patch :withdraw, params: { conference_id: conference.short_title, id: event.id }
         expect(assigns(:url)).to eq "/conferences/lama101/program/proposals/#{event.id}"
       end
 
       context 'withdraws successfully' do
         before do
-          patch :withdraw, conference_id: conference.short_title, id: event.id
+          patch :withdraw, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'changes state of event to withdrawn' do
@@ -374,7 +345,7 @@ describe ProposalsController do
         before do
           request.env['HTTP_REFERER'] = '/'
           allow_any_instance_of(Event).to receive(:withdraw).and_raise(Transitions::InvalidTransition)
-          patch :withdraw, conference_id: conference.short_title, id: event.id
+          patch :withdraw, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not withdraw event' do
@@ -394,7 +365,7 @@ describe ProposalsController do
       context 'event save fails' do
         before do
           allow_any_instance_of(Event).to receive(:save).and_return(false)
-          patch :withdraw, conference_id: conference.short_title, id: event.id
+          patch :withdraw, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not withdraw event' do
@@ -413,7 +384,7 @@ describe ProposalsController do
     end
 
     describe 'PATCH #confirm' do
-      before { event.update_attributes(state: 'unconfirmed') }
+      before { event.update(state: 'unconfirmed') }
 
       context 'confirmed successfully' do
         describe 'when require_registration is set' do
@@ -421,7 +392,7 @@ describe ProposalsController do
             event.require_registration = true
             event.max_attendees = nil
             event.save!
-            patch :confirm, conference_id: conference.short_title, id: event.id
+            patch :confirm, params: { conference_id: conference.short_title, id: event.id }
           end
 
           it 'assigns url variable' do
@@ -435,7 +406,7 @@ describe ProposalsController do
         end
 
         describe 'general actions' do
-          before { patch :confirm, conference_id: conference.short_title, id: event.id }
+          before { patch :confirm, params: { conference_id: conference.short_title, id: event.id } }
 
           it 'assigns url variable' do
             expect(assigns(:url)).to eq "/conferences/lama101/program/proposals/#{event.id}"
@@ -450,7 +421,7 @@ describe ProposalsController do
         context 'user has registered for the conference' do
           before do
             create(:registration, conference: conference, user: event.submitter)
-            patch :confirm, conference_id: conference.short_title, id: event.id
+            patch :confirm, params: { conference_id: conference.short_title, id: event.id }
           end
 
           it 'redirects to proposal index path' do
@@ -464,7 +435,7 @@ describe ProposalsController do
 
         context 'user has not registered for the conference' do
           before do
-            patch :confirm, conference_id: conference.short_title, id: event.id
+            patch :confirm, params: { conference_id: conference.short_title, id: event.id }
           end
 
           it 'redirects to new registration path' do
@@ -481,7 +452,7 @@ describe ProposalsController do
         before do
           request.env['HTTP_REFERER'] = '/'
           allow_any_instance_of(Event).to receive(:confirm).and_raise(Transitions::InvalidTransition)
-          patch :confirm, conference_id: conference.short_title, id: event.id
+          patch :confirm, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not confirm event' do
@@ -499,9 +470,9 @@ describe ProposalsController do
 
       context 'event save fails' do
         before do
-          event.update_attributes(state: 'unconfirmed')
+          event.update(state: 'unconfirmed')
           allow_any_instance_of(Event).to receive(:save).and_return(false)
-          patch :confirm, conference_id: conference.short_title, id: event.id
+          patch :confirm, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not confirm event' do
@@ -519,16 +490,16 @@ describe ProposalsController do
     end
 
     describe 'PATCH #restart' do
-      before { event.update_attributes(state: 'withdrawn') }
+      before { event.update(state: 'withdrawn') }
 
       it 'assigns url variable' do
-        patch :restart, conference_id: conference.short_title, id: event.id
+        patch :restart, params: { conference_id: conference.short_title, id: event.id }
         expect(assigns(:url)).to eq "/conferences/lama101/program/proposals/#{event.id}"
       end
 
       context 'resubmits successfully' do
         before do
-          patch :restart, conference_id: conference.short_title, id: event.id
+          patch :restart, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'changes state of event to new' do
@@ -548,7 +519,7 @@ describe ProposalsController do
       context 'event resubmission fails' do
         before do
           allow_any_instance_of(Event).to receive(:restart).and_raise(Transitions::InvalidTransition)
-          patch :restart, conference_id: conference.short_title, id: event.id
+          patch :restart, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not change state of event to new' do
@@ -568,7 +539,7 @@ describe ProposalsController do
       context 'event save fails' do
         before do
           allow_any_instance_of(Event).to receive(:save).and_return(false)
-          patch :restart, conference_id: conference.short_title, id: event.id
+          patch :restart, params: { conference_id: conference.short_title, id: event.id }
         end
 
         it 'does not change state of event to new' do
diff --git a/spec/controllers/schedules_controller_spec.rb b/spec/controllers/schedules_controller_spec.rb
index 6ff4875c..4c80adff 100644
--- a/spec/controllers/schedules_controller_spec.rb
+++ b/spec/controllers/schedules_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe SchedulesController do
@@ -11,13 +13,13 @@ describe SchedulesController do
         create(:event_scheduled, program: conference.program)
         create(:event_scheduled, program: conference.program)
 
-        get :show, conference_id: conference.short_title, format: :xml
+        get :show, params: { conference_id: conference.short_title, format: :xml }
       end
 
       it 'assigns variables' do
         expect(assigns(:conference)).to eq conference
         expect(assigns(:events_xml)).to eq conference.program.selected_event_schedules.map(&:event)
-                                           .group_by{ |event| event.time.to_date }
+                                                     .group_by { |event| event.time.to_date }
       end
 
       it 'has 200 status code' do
diff --git a/spec/controllers/subscriptions_controller_spec.rb b/spec/controllers/subscriptions_controller_spec.rb
index ac20a34b..dcc964a7 100644
--- a/spec/controllers/subscriptions_controller_spec.rb
+++ b/spec/controllers/subscriptions_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe SubscriptionsController do
@@ -7,7 +9,7 @@ describe SubscriptionsController do
   describe 'POST #create' do
     context 'when user is a guest' do
       it 'redirects to sign in page' do
-        post :create, conference_id: conference.short_title
+        post :create, params: { conference_id: conference.short_title }
         expect(response).to redirect_to new_user_session_path
       end
     end
@@ -18,17 +20,17 @@ describe SubscriptionsController do
       end
 
       it 'redirects to home page' do
-        post :create, conference_id: conference.short_title
+        post :create, params: { conference_id: conference.short_title }
         expect(response).to redirect_to root_path
       end
 
       it 'shows success message in flash notice' do
-        post :create, conference_id: conference.short_title
+        post :create, params: { conference_id: conference.short_title }
         expect(flash[:notice]).to match("You have subscribed to receive email notifications for #{conference.title}")
       end
 
       it 'subscribes user to conference' do
-        post :create, conference_id: conference.short_title
+        post :create, params: { conference_id: conference.short_title }
         expect(user.subscriptions.pluck(:conference_id)).to include(conference.id)
       end
     end
@@ -37,17 +39,17 @@ describe SubscriptionsController do
   describe 'DELETE #destroy' do
     before(:each) do
       sign_in(user)
-      post :create, conference_id: conference.short_title
+      post :create, params: { conference_id: conference.short_title }
     end
 
     it 'redirects to home page' do
-      delete :destroy, conference_id: conference.short_title
+      delete :destroy, params: { conference_id: conference.short_title }
       expect(response).to redirect_to root_path
     end
 
     it 'shows success message in flash notice' do
-      delete :destroy, conference_id: conference.short_title
-        expect(flash[:notice]).to match("You have unsubscribed and you will not be receiving email notifications for #{conference.title}.")
+      delete :destroy, params: { conference_id: conference.short_title }
+      expect(flash[:notice]).to match("You have unsubscribed and you will not be receiving email notifications for #{conference.title}.")
     end
   end
 end
diff --git a/spec/controllers/tracks_controller_spec.rb b/spec/controllers/tracks_controller_spec.rb
index a555dba8..73cba633 100644
--- a/spec/controllers/tracks_controller_spec.rb
+++ b/spec/controllers/tracks_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe TracksController do
@@ -13,7 +15,7 @@ describe TracksController do
 
   describe 'GET #index' do
     before :each do
-      get :index, conference_id: conference.short_title
+      get :index, params: { conference_id: conference.short_title }
     end
 
     it 'assigns @tracks with the correct values' do
@@ -29,7 +31,7 @@ describe TracksController do
 
   describe 'GET #show' do
     before :each do
-      get :show, conference_id: conference.short_title, id: self_organized_track.short_name
+      get :show, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
     end
 
     it 'assigns the correct track' do
@@ -43,7 +45,7 @@ describe TracksController do
 
   describe 'GET #new' do
     before :each do
-      get :new, conference_id: conference.short_title
+      get :new, params: { conference_id: conference.short_title }
     end
 
     it 'assigns a new track with the correct conference' do
@@ -60,7 +62,7 @@ describe TracksController do
   describe 'POST #create' do
     context 'saves successfuly' do
       before :each do
-        post :create, track: attributes_for(:track, :self_organized, short_name: 'my_track'), conference_id: conference.short_title
+        post :create, params: { track: attributes_for(:track, :self_organized, short_name: 'my_track'), conference_id: conference.short_title }
       end
 
       it 'redirects to tracks index path' do
@@ -86,7 +88,7 @@ describe TracksController do
     context 'save fails' do
       before :each do
         allow_any_instance_of(Track).to receive(:save).and_return(false)
-        post :create, track: attributes_for(:track, :self_organized, short_name: 'my_track'), conference_id: conference.short_title
+        post :create, params: { track: attributes_for(:track, :self_organized, short_name: 'my_track'), conference_id: conference.short_title }
       end
 
       it 'assigns a new track with the correct conference' do
@@ -111,7 +113,7 @@ describe TracksController do
 
   describe 'GET #edit' do
     before :each do
-      get :edit, conference_id: conference.short_title, id: self_organized_track.short_name
+      get :edit, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
     end
 
     it 'assigns the correct track' do
@@ -126,9 +128,7 @@ describe TracksController do
   describe 'PATCH #update' do
     context 'updates successfully' do
       before :each do
-        patch :update, track: attributes_for(:track, :self_organized, color: '#FF0000'),
-                       conference_id: conference.short_title,
-                       id: self_organized_track.short_name
+        patch :update, params: { track: attributes_for(:track, :self_organized, color: '#FF0000'), conference_id: conference.short_title, id: self_organized_track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -152,9 +152,7 @@ describe TracksController do
     context 'update fails' do
       before :each do
         allow_any_instance_of(Track).to receive(:save).and_return(false)
-        patch :update, track: attributes_for(:track, :self_organized, color: '#FF0000'),
-                       conference_id: conference.short_title,
-                       id: self_organized_track.short_name
+        patch :update, params: { track: attributes_for(:track, :self_organized, color: '#FF0000'), conference_id: conference.short_title, id: self_organized_track.short_name }
       end
 
       it 'assigns the correct track' do
@@ -180,7 +178,7 @@ describe TracksController do
     before :each do
       self_organized_track.state = 'withdrawn'
       self_organized_track.save!
-      patch :restart, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :restart, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -201,7 +199,7 @@ describe TracksController do
     before :each do
       self_organized_track.state = 'accepted'
       self_organized_track.save!
-      patch :confirm, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :confirm, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
@@ -222,7 +220,7 @@ describe TracksController do
     before :each do
       self_organized_track.state = 'confirmed'
       self_organized_track.save!
-      patch :withdraw, conference_id: conference.short_title, id: self_organized_track.short_name
+      patch :withdraw, params: { conference_id: conference.short_title, id: self_organized_track.short_name }
       self_organized_track.reload
     end
 
diff --git a/spec/controllers/users/omniauth_callbacks_controller_spec.rb b/spec/controllers/users/omniauth_callbacks_controller_spec.rb
index 7204fe33..c5281085 100644
--- a/spec/controllers/users/omniauth_callbacks_controller_spec.rb
+++ b/spec/controllers/users/omniauth_callbacks_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Users::OmniauthCallbacksController do
@@ -14,17 +16,17 @@ end
 def stub_env_for_omniauth
   request.env['devise.mapping'] = Devise.mappings[:user]
   env = OmniAuth::AuthHash.new(
-                                provider: 'google',
-                                uid: 'google-test-uid-1',
-                                info: {
-                                  name: 'google user',
-                                  email: nil,
-                                  username: 'user_google'
-                                },
-                                credentials: {
-                                  token: 'google_mock_token',
-                                  secret: 'google_mock_secret'
-                                }
+    provider: 'google',
+    uid: 'google-test-uid-1',
+    info: {
+      name: 'google user',
+      email: nil,
+      username: 'user_google'
+    },
+    credentials: {
+      token: 'google_mock_token',
+      secret: 'google_mock_secret'
+    }
   )
   request.env['omniauth.auth'] = env
   allow(@controller).to receive(:env).and_return(env)
diff --git a/spec/controllers/users_controller_spec.rb b/spec/controllers/users_controller_spec.rb
index e46e134c..c2010e89 100644
--- a/spec/controllers/users_controller_spec.rb
+++ b/spec/controllers/users_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe UsersController do
@@ -6,7 +8,7 @@ describe UsersController do
 
   describe 'GET #show' do
     before :each do
-      get :show, id: user.id
+      get :show, params: { id: user.id }
     end
 
     it 'renders show template' do
@@ -33,7 +35,7 @@ describe UsersController do
   describe 'GET #edit' do
     it 'assigns the right value to @user' do
       sign_in user
-      get :edit, id: user.id
+      get :edit, params: { id: user.id }
       expect(assigns(:user)).to eq user
     end
   end
@@ -42,7 +44,7 @@ describe UsersController do
     context 'with valid attributes' do
       before :each do
         sign_in user
-        patch :update, id: user.id, user: attributes_for(:user, name: 'My Test Name')
+        patch :update, params: { id: user.id, user: attributes_for(:user, name: 'My Test Name') }
         user.reload
       end
 
diff --git a/spec/factories/answer.rb b/spec/factories/answer.rb
index 367ba3a9..f2c69c32 100644
--- a/spec/factories/answer.rb
+++ b/spec/factories/answer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/booth_request.rb b/spec/factories/booth_request.rb
index fba0cace..02f21c41 100644
--- a/spec/factories/booth_request.rb
+++ b/spec/factories/booth_request.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :booth_request do
     booth
     user
     role 'responsible'
-
   end
 end
diff --git a/spec/factories/booths.rb b/spec/factories/booths.rb
index 1ac3ff87..eff90c44 100644
--- a/spec/factories/booths.rb
+++ b/spec/factories/booths.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :booth do
     title { Faker::Hipster.sentence }
diff --git a/spec/factories/campaigns.rb b/spec/factories/campaigns.rb
index 5c04a6d4..dc745487 100644
--- a/spec/factories/campaigns.rb
+++ b/spec/factories/campaigns.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/cfps.rb b/spec/factories/cfps.rb
index ea59a8c1..d7932e2d 100644
--- a/spec/factories/cfps.rb
+++ b/spec/factories/cfps.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/comments.rb b/spec/factories/comments.rb
index a424e23b..736ba0ba 100644
--- a/spec/factories/comments.rb
+++ b/spec/factories/comments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/commercials.rb b/spec/factories/commercials.rb
index 7fa052a7..00404b36 100644
--- a/spec/factories/commercials.rb
+++ b/spec/factories/commercials.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/conferences.rb b/spec/factories/conferences.rb
index d0f11d19..7447b36c 100644
--- a/spec/factories/conferences.rb
+++ b/spec/factories/conferences.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
@@ -31,7 +33,7 @@ FactoryGirl.define do
         # Contact/Program is created by Conference callbacks
         conference.contact.destroy
         conference.contact = create(:contact, conference: conference)
-        conference.program.update_attributes(schedule_public: true)
+        conference.program.update(schedule_public: true)
 
         create(:cfp, program: conference.program)
         create_list(:track, 2, program: conference.program)
diff --git a/spec/factories/contacts.rb b/spec/factories/contacts.rb
index 9168f22b..ac3bccc1 100644
--- a/spec/factories/contacts.rb
+++ b/spec/factories/contacts.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :contact do
     social_tag { SecureRandom.urlsafe_base64(4) }
diff --git a/spec/factories/difficulty_levels.rb b/spec/factories/difficulty_levels.rb
index 7a1e8da5..9c147830 100644
--- a/spec/factories/difficulty_levels.rb
+++ b/spec/factories/difficulty_levels.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :difficulty_level do
     title 'Example Difficulty Level'
diff --git a/spec/factories/email_settings.rb b/spec/factories/email_settings.rb
index d10a6b51..db8a1480 100644
--- a/spec/factories/email_settings.rb
+++ b/spec/factories/email_settings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/event_schedule.rb b/spec/factories/event_schedule.rb
index a72e3745..208f7e29 100644
--- a/spec/factories/event_schedule.rb
+++ b/spec/factories/event_schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
@@ -8,10 +10,10 @@ FactoryGirl.define do
       unless (venue = program.conference.venue)
         venue = create(:venue, conference: program.conference)
       end
-      (event_schedule.room = create(:room, venue: venue)) unless event_schedule.room.present?
-      (event_schedule.start_time = program.conference.start_date + program.conference.start_hour.hours) unless event_schedule.start_time.present?
-      unless event_schedule.schedule.present?
-        unless program.selected_schedule.present?
+      (event_schedule.room = create(:room, venue: venue)) if event_schedule.room.blank?
+      (event_schedule.start_time = program.conference.start_date + program.conference.start_hour.hours) if event_schedule.start_time.blank?
+      if event_schedule.schedule.blank?
+        if program.selected_schedule.blank?
           schedule = create(:schedule, program: program)
           program.schedules << schedule
           program.selected_schedule = schedule
diff --git a/spec/factories/event_types.rb b/spec/factories/event_types.rb
index 5686254d..f2a282b1 100644
--- a/spec/factories/event_types.rb
+++ b/spec/factories/event_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
@@ -9,5 +11,4 @@ FactoryGirl.define do
     color '#ffffff'
     program
   end
-
 end
diff --git a/spec/factories/event_users.rb b/spec/factories/event_users.rb
index 5d1574a9..f0830243 100644
--- a/spec/factories/event_users.rb
+++ b/spec/factories/event_users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/events.rb b/spec/factories/events.rb
index 731c774e..37fbc454 100644
--- a/spec/factories/events.rb
+++ b/spec/factories/events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
@@ -22,9 +24,7 @@ FactoryGirl.define do
         event.commercials << build(:event_commercial, commercialable: event)
         event.difficulty_level = build(:difficulty_level, program: event.program)
         event.track = build(:track, program: event.program)
-        unless event.program.conference.venue
-          create(:venue, conference: event.program.conference)
-        end
+        create(:venue, conference: event.program.conference) unless event.program.conference.venue
         event.comment_threads << build(:comment, commentable: event)
       end
 
diff --git a/spec/factories/events_registrations.rb b/spec/factories/events_registrations.rb
index 8fd7286c..84012f57 100644
--- a/spec/factories/events_registrations.rb
+++ b/spec/factories/events_registrations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/lodgings.rb b/spec/factories/lodgings.rb
index a4bbf73c..42d02c0b 100644
--- a/spec/factories/lodgings.rb
+++ b/spec/factories/lodgings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/openid.rb b/spec/factories/openid.rb
index 6950c718..60dcf29f 100644
--- a/spec/factories/openid.rb
+++ b/spec/factories/openid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/organizations.rb b/spec/factories/organizations.rb
index f6331873..8b10893b 100644
--- a/spec/factories/organizations.rb
+++ b/spec/factories/organizations.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :organization do
     sequence(:name) { |n| "#{Faker::Company.name} #{n}" }
diff --git a/spec/factories/payments.rb b/spec/factories/payments.rb
index 4d4d3c39..71a7adff 100644
--- a/spec/factories/payments.rb
+++ b/spec/factories/payments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :payment do
     user
diff --git a/spec/factories/physical_ticket.rb b/spec/factories/physical_ticket.rb
index 8b4f2a0e..0356657f 100644
--- a/spec/factories/physical_ticket.rb
+++ b/spec/factories/physical_ticket.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :physical_ticket do
     ticket_purchase
diff --git a/spec/factories/programs.rb b/spec/factories/programs.rb
index e3c20153..c6345088 100644
--- a/spec/factories/programs.rb
+++ b/spec/factories/programs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/qanswer.rb b/spec/factories/qanswer.rb
index 136b5655..962392a1 100644
--- a/spec/factories/qanswer.rb
+++ b/spec/factories/qanswer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/question.rb b/spec/factories/question.rb
index 5a2a58e5..310e61b9 100644
--- a/spec/factories/question.rb
+++ b/spec/factories/question.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/question_type.rb b/spec/factories/question_type.rb
index aeb77096..15a942b9 100644
--- a/spec/factories/question_type.rb
+++ b/spec/factories/question_type.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/registration.rb b/spec/factories/registration.rb
index fb79cb4d..1cdb297d 100644
--- a/spec/factories/registration.rb
+++ b/spec/factories/registration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/registration_periods.rb b/spec/factories/registration_periods.rb
index bb775aa9..333c29d0 100644
--- a/spec/factories/registration_periods.rb
+++ b/spec/factories/registration_periods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/resource.rb b/spec/factories/resource.rb
index 83045e9e..4848f09d 100644
--- a/spec/factories/resource.rb
+++ b/spec/factories/resource.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :resource do
     name { 'Resource' }
diff --git a/spec/factories/roles.rb b/spec/factories/roles.rb
index 67d85233..a2997a91 100644
--- a/spec/factories/roles.rb
+++ b/spec/factories/roles.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :role do
     name 'my role'
diff --git a/spec/factories/rooms.rb b/spec/factories/rooms.rb
index 7347b95d..7e3ebe65 100644
--- a/spec/factories/rooms.rb
+++ b/spec/factories/rooms.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 FactoryGirl.define do
   factory :room do
diff --git a/spec/factories/schedule.rb b/spec/factories/schedule.rb
index e1c9dc2f..8a5635d9 100644
--- a/spec/factories/schedule.rb
+++ b/spec/factories/schedule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/splashpages.rb b/spec/factories/splashpages.rb
index 752a36f3..80c9f0f6 100644
--- a/spec/factories/splashpages.rb
+++ b/spec/factories/splashpages.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/sponsors.rb b/spec/factories/sponsors.rb
index 5d531991..f8edf4a6 100644
--- a/spec/factories/sponsors.rb
+++ b/spec/factories/sponsors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
@@ -9,7 +11,7 @@ FactoryGirl.define do
     sponsorship_level
 
     after(:create) do |sponsor|
-      File.open("spec/support/logos/#{1 + rand(13)}.png") do |file|
+      File.open("spec/support/logos/#{rand(1..13)}.png") do |file|
         sponsor.picture = file
       end
       sponsor.save!
diff --git a/spec/factories/sponsorship_levels.rb b/spec/factories/sponsorship_levels.rb
index 72db7493..6b8a4da9 100644
--- a/spec/factories/sponsorship_levels.rb
+++ b/spec/factories/sponsorship_levels.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/subscriptions.rb b/spec/factories/subscriptions.rb
index 0816b70f..169a45d7 100644
--- a/spec/factories/subscriptions.rb
+++ b/spec/factories/subscriptions.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :subscription do
     user
     conference
   end
-
 end
diff --git a/spec/factories/targets.rb b/spec/factories/targets.rb
index 9d65f2ba..8318b081 100644
--- a/spec/factories/targets.rb
+++ b/spec/factories/targets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/ticket_purchases.rb b/spec/factories/ticket_purchases.rb
index bee365cf..9b339ed9 100644
--- a/spec/factories/ticket_purchases.rb
+++ b/spec/factories/ticket_purchases.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :ticket_purchase do
     user
diff --git a/spec/factories/ticket_scanning.rb b/spec/factories/ticket_scanning.rb
index 540d1fd0..df18fc80 100644
--- a/spec/factories/ticket_scanning.rb
+++ b/spec/factories/ticket_scanning.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :ticket_scanning do
     physical_ticket
diff --git a/spec/factories/tickets.rb b/spec/factories/tickets.rb
index c4bb1539..ba623044 100644
--- a/spec/factories/tickets.rb
+++ b/spec/factories/tickets.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :ticket do
     title { "#{Faker::Hipster.word} Ticket" }
diff --git a/spec/factories/tracks.rb b/spec/factories/tracks.rb
index 097a5452..eda41a11 100644
--- a/spec/factories/tracks.rb
+++ b/spec/factories/tracks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :track do
     name { Faker::Commerce.department(2, true) }
diff --git a/spec/factories/users.rb b/spec/factories/users.rb
index e2e78c16..1e3ffdea 100644
--- a/spec/factories/users.rb
+++ b/spec/factories/users.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 # It is a feature of our app that first signed up user is admin. This property
@@ -54,5 +56,4 @@ FactoryGirl.define do
   factory :user_xss, parent: :user do
     biography '<div id="divInjectedElement"></div>'
   end
-
 end
diff --git a/spec/factories/vdays.rb b/spec/factories/vdays.rb
index 7d7c2976..724e6cb1 100644
--- a/spec/factories/vdays.rb
+++ b/spec/factories/vdays.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :vday do
     day { Time.zone.today }
     description 'Lorem Ipsum dolsum'
     conference
   end
-
 end
diff --git a/spec/factories/venues.rb b/spec/factories/venues.rb
index 92c149cc..a240f951 100644
--- a/spec/factories/venues.rb
+++ b/spec/factories/venues.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 FactoryGirl.define do
   factory :venue do
diff --git a/spec/factories/visits.rb b/spec/factories/visits.rb
index 3a03b203..145e919d 100644
--- a/spec/factories/visits.rb
+++ b/spec/factories/visits.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Read about factories at https://github.com/thoughtbot/factory_girl
 
 FactoryGirl.define do
diff --git a/spec/factories/votes.rb b/spec/factories/votes.rb
index 12ede741..6fe973d9 100644
--- a/spec/factories/votes.rb
+++ b/spec/factories/votes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :vote do
     event
diff --git a/spec/factories/vpositions.rb b/spec/factories/vpositions.rb
index 6bfcc769..2885ee2f 100644
--- a/spec/factories/vpositions.rb
+++ b/spec/factories/vpositions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 FactoryGirl.define do
   factory :vposition do
     title 'Example Volunteer Position'
@@ -8,5 +10,4 @@ FactoryGirl.define do
       vposition.vdays << build(:vday, conference: vposition.conference)
     end
   end
-
 end
diff --git a/spec/features/base_controller_spec.rb b/spec/features/base_controller_spec.rb
index 1f75f81b..57d5be94 100644
--- a/spec/features/base_controller_spec.rb
+++ b/spec/features/base_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'BaseController' do
diff --git a/spec/features/campaign_spec.rb b/spec/features/campaign_spec.rb
index c2fa8de6..3eb852bd 100644
--- a/spec/features/campaign_spec.rb
+++ b/spec/features/campaign_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Campaign do
-
   let!(:conference) { create(:conference, short_title: 'osc14') }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let!(:organizer) { create(:user, role_ids: [organizer_role.id]) }
diff --git a/spec/features/cfp_ability_spec.rb b/spec/features/cfp_ability_spec.rb
index 7229ab8d..910205c0 100644
--- a/spec/features/cfp_ability_spec.rb
+++ b/spec/features/cfp_ability_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
-
   let(:organization) { create(:organization) }
   let(:conference) { create(:full_conference, organization: organization) }
   let(:role_cfp) { Role.find_by(name: 'cfp', resource: conference) }
diff --git a/spec/features/cfp_spec.rb b/spec/features/cfp_spec.rb
index 7ecfb1e6..40971393 100644
--- a/spec/features/cfp_spec.rb
+++ b/spec/features/cfp_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Conference do
-
   let!(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let!(:organizer) { create(:user, role_ids: [organizer_role.id]) }
@@ -17,20 +18,22 @@ feature Conference do
       click_button 'Create Cfp'
 
       expect(flash)
-          .to eq('Creating the call for papers failed. ' +
+        .to eq('Creating the call for papers failed. ' \
           "Start date can't be blank. End date can't be blank.")
 
       today = Date.today - 1
       page.execute_script(
-      "$('#registration-period-start-datepicker').val('#{today.strftime('%d/%m/%Y')}')")
+        "$('#registration-period-start-datepicker').val('#{today.strftime('%d/%m/%Y')}')"
+      )
       page.execute_script(
-      "$('#registration-period-end-datepicker').val('#{(today + 6).strftime('%d/%m/%Y')}')")
+        "$('#registration-period-end-datepicker').val('#{(today + 6).strftime('%d/%m/%Y')}')"
+      )
 
       click_button 'Create Cfp'
 
       # Validations
       expect(flash)
-          .to eq('Call for papers successfully created.')
+        .to eq('Call for papers successfully created.')
 
       visit admin_conference_program_cfp_path(conference.short_title, conference.program.cfp)
       expect(find('#start_date').text).to eq(today.strftime('%A, %B %-d. %Y'))
@@ -49,24 +52,27 @@ feature Conference do
 
       # Validate update with empty start date will not saved
       page.execute_script(
-          "$('#registration-period-start-datepicker').val('')")
+        "$('#registration-period-start-datepicker').val('')"
+      )
       click_button 'Update Cfp'
       expect(flash)
-          .to eq('Updating call for papers failed. ' +
+        .to eq('Updating call for papers failed. ' \
                     "Start date can't be blank.")
 
       # Fill in date
       today = Date.today - 9
       page.execute_script(
-        "$('#registration-period-start-datepicker').val('#{today.strftime('%d/%m/%Y')}')")
+        "$('#registration-period-start-datepicker').val('#{today.strftime('%d/%m/%Y')}')"
+      )
       page.execute_script(
-        "$('#registration-period-end-datepicker').val('#{(today + 14).strftime('%d/%m/%Y')}')")
+        "$('#registration-period-end-datepicker').val('#{(today + 14).strftime('%d/%m/%Y')}')"
+      )
 
       click_button 'Update Cfp'
 
       # Validations
       expect(flash)
-          .to eq('Call for papers successfully updated.')
+        .to eq('Call for papers successfully updated.')
 
       visit admin_conference_program_cfp_path(conference.short_title, conference.program.cfp)
       expect(find('#start_date').text).to eq(today.strftime('%A, %B %-d. %Y'))
diff --git a/spec/features/commercials_spec.rb b/spec/features/commercials_spec.rb
index d460a725..84bca335 100644
--- a/spec/features/commercials_spec.rb
+++ b/spec/features/commercials_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Commercial do
diff --git a/spec/features/conference_registration_spec.rb b/spec/features/conference_registration_spec.rb
index 32ea2320..82f4a111 100644
--- a/spec/features/conference_registration_spec.rb
+++ b/spec/features/conference_registration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Registration do
diff --git a/spec/features/conference_spec.rb b/spec/features/conference_spec.rb
index bfd0be39..286b8a52 100644
--- a/spec/features/conference_spec.rb
+++ b/spec/features/conference_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Conference do
@@ -18,20 +20,20 @@ feature Conference do
 
       today = Time.zone.today - 1
       page
-      .execute_script("$('#conference-start-datepicker').val('" +
+        .execute_script("$('#conference-start-datepicker').val('" \
                          "#{today.strftime('%d/%m/%Y')}')")
       page
-      .execute_script("$('#conference-end-datepicker').val('" +
+        .execute_script("$('#conference-end-datepicker').val('" \
                          "#{(today + 7).strftime('%d/%m/%Y')}')")
 
       click_button 'Create Conference'
 
       expect(flash)
-          .to eq('Conference was successfully created.')
+        .to eq('Conference was successfully created.')
       expect(Conference.count).to eq(expected_count)
       expect(Conference.last.organization).to eq(organization)
       user.reload
-      expect(user.has_cached_role? :organizer, Conference.last).to eq(true)
+      expect(user.has_cached_role?(:organizer, Conference.last)).to eq(true)
     end
 
     scenario 'update conference', feature: true, js: true do
@@ -49,22 +51,22 @@ feature Conference do
 
       click_button 'Update Conference'
       expect(flash)
-          .to eq("Updating conference failed. Short title can't be blank.")
+        .to eq("Updating conference failed. Short title can't be blank.")
 
       fill_in 'conference_title', with: 'New Con'
       fill_in 'conference_short_title', with: 'NewCon'
 
       day = Time.zone.today + 10
       page
-          .execute_script("$('#conference-start-datepicker').val('" +
+        .execute_script("$('#conference-start-datepicker').val('" \
                              "#{day.strftime('%d/%m/%Y')}')")
       page
-          .execute_script("$('#conference-end-datepicker').val('" +
+        .execute_script("$('#conference-end-datepicker').val('" \
                              "#{(day + 7).strftime('%d/%m/%Y')}')")
 
       click_button 'Update Conference'
       expect(flash)
-          .to eq('Conference was successfully updated.')
+        .to eq('Conference was successfully updated.')
 
       conference.reload
       expect(conference.title).to eq('New Con')
diff --git a/spec/features/contact_spec.rb b/spec/features/contact_spec.rb
index 513f3cab..9201644d 100644
--- a/spec/features/contact_spec.rb
+++ b/spec/features/contact_spec.rb
@@ -1,13 +1,13 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Contact do
-
   let!(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
   let!(:organizer) { create(:user, email: 'admin@example.com', role_ids: [organizer_role.id]) }
 
   shared_examples 'update a contact' do
-
     scenario 'sucessfully', feature: true, js: true do
       contact = conference.contact
       expected_count = Contact.count
@@ -26,7 +26,7 @@ feature Contact do
       click_button 'Update Contact'
 
       expect(flash)
-          .to eq('Contact details were successfully updated.')
+        .to eq('Contact details were successfully updated.')
       contact.reload
       expect(contact.email).to eq('example@example.com')
       expect(contact.sponsor_email).to eq('sponsor@example.com')
@@ -42,5 +42,4 @@ feature Contact do
   describe 'organizer' do
     it_behaves_like 'update a contact', :organizer
   end
-
 end
diff --git a/spec/features/difficulty_levels_spec.rb b/spec/features/difficulty_levels_spec.rb
index 64427547..f6b881ba 100644
--- a/spec/features/difficulty_levels_spec.rb
+++ b/spec/features/difficulty_levels_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature DifficultyLevel do
@@ -7,10 +9,10 @@ feature DifficultyLevel do
 
   shared_examples 'difficulty levels' do
     scenario 'adds difficulty level', feature: true, js: true do
-
       sign_in organizer
       visit admin_conference_program_difficulty_levels_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       # Add difficulty level
       click_link 'Add Difficulty Level'
@@ -31,11 +33,11 @@ feature DifficultyLevel do
     end
 
     scenario 'updates difficulty level', feature: true, js: true do
-
       conference.program.difficulty_levels << create(:difficulty_level)
       sign_in organizer
       visit admin_conference_program_difficulty_levels_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       # Remove difficulty level
       within('table tr:nth-of-type(4)') do
@@ -51,7 +53,6 @@ feature DifficultyLevel do
         expect(page.has_content?('Hard Events')).to be true
       end
     end
-
   end
 
   describe 'organizer' do
diff --git a/spec/features/email_spec.rb b/spec/features/email_spec.rb
index c1bfef5d..39aeff3e 100644
--- a/spec/features/email_spec.rb
+++ b/spec/features/email_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature EmailSettings do
@@ -54,7 +56,7 @@ feature EmailSettings do
       click_button 'Update Email settings'
 
       expect(flash)
-          .to eq('Email settings have been successfully updated.')
+        .to eq('Email settings have been successfully updated.')
 
       expect(find('#email_settings_registration_subject')
                  .value).to eq('Registration subject')
@@ -88,7 +90,6 @@ feature EmailSettings do
                  .value).to eq('Updated conference venue template')
 
       expect(EmailSettings.count).to eq(expected_count)
-
     end
   end
 
diff --git a/spec/features/event_types_spec.rb b/spec/features/event_types_spec.rb
index 6b3c9f0c..c6093c86 100644
--- a/spec/features/event_types_spec.rb
+++ b/spec/features/event_types_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature EventType do
@@ -7,10 +9,10 @@ feature EventType do
 
   shared_examples 'event types' do
     scenario 'adds and updates event type', feature: true do
-
       sign_in organizer
       visit admin_conference_program_event_types_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       within('table#event_types') do
         expect(page.assert_selector('tr', count: 2)).to be true
diff --git a/spec/features/info_desk_ability_spec.rb b/spec/features/info_desk_ability_spec.rb
index f4ef4fce..e32d6cb8 100644
--- a/spec/features/info_desk_ability_spec.rb
+++ b/spec/features/info_desk_ability_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
-
   let(:organization) { create(:organization) }
   let(:conference) { create(:full_conference, organization: organization) }
   let(:role_info_desk) { Role.find_by(name: 'info_desk', resource: conference) }
diff --git a/spec/features/lodgings_spec.rb b/spec/features/lodgings_spec.rb
index 1e6b491d..5f265a54 100644
--- a/spec/features/lodgings_spec.rb
+++ b/spec/features/lodgings_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Lodging do
@@ -10,7 +12,8 @@ feature Lodging do
 
     sign_in organizer
     visit admin_conference_lodgings_path(
-              conference_id: conference.short_title)
+      conference_id: conference.short_title
+    )
     # Add lodging
     click_link 'Add Lodging'
 
@@ -33,7 +36,8 @@ feature Lodging do
 
     sign_in organizer
     visit admin_conference_lodgings_path(
-              conference_id: conference.short_title)
+      conference_id: conference.short_title
+    )
 
     expect(page.has_content?(CGI.escapeHTML(lodging.name))).to be true
 
@@ -61,7 +65,8 @@ feature Lodging do
 
     sign_in organizer
     visit admin_conference_lodgings_path(
-              conference_id: conference.short_title)
+      conference_id: conference.short_title
+    )
 
     expect(page.has_content?(lodging.name)).to be true
 
diff --git a/spec/features/omniauth_spec.rb b/spec/features/omniauth_spec.rb
index 419d1f03..e346bba0 100644
--- a/spec/features/omniauth_spec.rb
+++ b/spec/features/omniauth_spec.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Openid do
   shared_examples 'sign in with openid' do
-
     scenario 'has option to log in with Google account' do
       visit '/accounts/sign_in'
       expect(page.has_content?('or sign in using')).to be true
diff --git a/spec/features/organization_admin_ability_spec.rb b/spec/features/organization_admin_ability_spec.rb
index d84a7c01..6fa6b090 100644
--- a/spec/features/organization_admin_ability_spec.rb
+++ b/spec/features/organization_admin_ability_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
diff --git a/spec/features/organization_spec.rb b/spec/features/organization_spec.rb
index 72948c2d..e2cf2fb0 100644
--- a/spec/features/organization_spec.rb
+++ b/spec/features/organization_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Organization do
diff --git a/spec/features/organizer_ability_spec.rb b/spec/features/organizer_ability_spec.rb
index 0127ea2f..15e127ee 100644
--- a/spec/features/organizer_ability_spec.rb
+++ b/spec/features/organizer_ability_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
-
   let(:organization) { create(:organization) }
   let(:conference) { create(:full_conference, organization: organization) }
   let(:other_conference) { create(:conference, organization: organization) } # user is organizer, venue is not set by default
diff --git a/spec/features/program_spec.rb b/spec/features/program_spec.rb
index 369a0525..f4c13a93 100644
--- a/spec/features/program_spec.rb
+++ b/spec/features/program_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Program do
-
   let!(:conference) { create(:conference) }
   let!(:program) { conference.program }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -23,7 +24,7 @@ feature Program do
 
       # Validations
       expect(flash)
-          .to eq('The program was successfully updated.')
+        .to eq('The program was successfully updated.')
       expect(find('#rating').text).to eq('4')
     end
   end
diff --git a/spec/features/proposals_spec.rb b/spec/features/proposals_spec.rb
index bef01e43..a5ad2430 100644
--- a/spec/features/proposals_spec.rb
+++ b/spec/features/proposals_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Event do
diff --git a/spec/features/registration_periods_spec.rb b/spec/features/registration_periods_spec.rb
index 5c1c90b5..4faff9b3 100644
--- a/spec/features/registration_periods_spec.rb
+++ b/spec/features/registration_periods_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature RegistrationPeriod do
-
   # It is necessary to use bang version of let to build roles before user
   let!(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -12,20 +13,21 @@ feature RegistrationPeriod do
     scenario 'create and update registration period', js: true do
       sign_in organizer
       visit admin_conference_registration_period_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       click_link 'New Registration Period'
 
       click_button 'Save Registration Period'
       expect(flash)
-          .to eq('An error prohibited the Registration Period from being saved: ' \
+        .to eq('An error prohibited the Registration Period from being saved: ' \
           "Start date can't be blank. End date can't be blank.")
 
       page
-          .execute_script("$('#registration-period-start-datepicker').val('" +
+        .execute_script("$('#registration-period-start-datepicker').val('" \
                              "#{Date.today.strftime('%d/%m/%Y')}')")
       page
-          .execute_script("$('#registration-period-end-datepicker').val('" +
+        .execute_script("$('#registration-period-end-datepicker').val('" \
                              "#{(Date.today + 5).strftime('%d/%m/%Y')}')")
 
       click_button 'Save Registration Period'
diff --git a/spec/features/resource_spec.rb b/spec/features/resource_spec.rb
index 1d5c0437..895588aa 100644
--- a/spec/features/resource_spec.rb
+++ b/spec/features/resource_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Resource do
diff --git a/spec/features/roles_spec.rb b/spec/features/roles_spec.rb
index 00d15006..9b01d493 100644
--- a/spec/features/roles_spec.rb
+++ b/spec/features/roles_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Role do
diff --git a/spec/features/rooms_spec.rb b/spec/features/rooms_spec.rb
index d4ff4e0a..beb7402f 100644
--- a/spec/features/rooms_spec.rb
+++ b/spec/features/rooms_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Room do
@@ -10,7 +12,8 @@ feature Room do
     scenario 'adds a room', feature: true, js: true do
       sign_in organizer
       visit admin_conference_venue_rooms_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       expect(page.has_no_table?('#rooms')).to be true
 
@@ -34,7 +37,8 @@ feature Room do
       room = create(:room, venue: venue)
       sign_in organizer
       visit edit_admin_conference_venue_room_path(
-                conference_id: conference.short_title, id: room.id)
+        conference_id: conference.short_title, id: room.id
+      )
 
       fill_in 'room_name', with: 'Auditorium'
       fill_in 'room_size', with: '100'
diff --git a/spec/features/splashpage_spec.rb b/spec/features/splashpage_spec.rb
index 006df419..69c31052 100644
--- a/spec/features/splashpage_spec.rb
+++ b/spec/features/splashpage_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Splashpage do
-
   # It is necessary to use bang version of let to build roles before user
   let!(:conference) { create(:conference) }
   let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -20,7 +21,7 @@ feature Splashpage do
   end
 
   context 'splashpage already created' do
-    let!(:splashpage) { create(:splashpage, conference: conference, public: false)}
+    let!(:splashpage) { create(:splashpage, conference: conference, public: false) }
 
     scenario 'update a valid splashpage', js: true do
       sign_in organizer
@@ -63,7 +64,7 @@ feature Splashpage do
   end
 
   context 'navigation' do
-    let!(:splashpage) { create(:splashpage, conference: conference, public: true)}
+    let!(:splashpage) { create(:splashpage, conference: conference, public: true) }
 
     context 'multiple organizations' do
       let!(:additional_organization) { create(:organization) }
diff --git a/spec/features/sponsor_spec.rb b/spec/features/sponsor_spec.rb
index b12ee90d..ef517406 100644
--- a/spec/features/sponsor_spec.rb
+++ b/spec/features/sponsor_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Sponsor do
@@ -13,7 +15,8 @@ feature Sponsor do
       sign_in organizer
 
       visit admin_conference_sponsors_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
       # Add sponsors
       click_link 'Add Sponsor'
 
diff --git a/spec/features/sponsorship_level_spec.rb b/spec/features/sponsorship_level_spec.rb
index 3140a16b..5d30da88 100644
--- a/spec/features/sponsorship_level_spec.rb
+++ b/spec/features/sponsorship_level_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature SponsorshipLevel do
@@ -9,7 +11,8 @@ feature SponsorshipLevel do
     scenario 'adds a sponsorship level', feature: true, js: true do
       sign_in organizer
       visit admin_conference_sponsorship_levels_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       expect(page.has_no_table?('#sponsorship_levels')).to be true
 
@@ -32,7 +35,8 @@ feature SponsorshipLevel do
       level = create(:sponsorship_level, conference_id: conference.id)
       sign_in organizer
       visit edit_admin_conference_sponsorship_level_path(
-                conference_id: conference.short_title, id: level.id)
+        conference_id: conference.short_title, id: level.id
+      )
 
       fill_in 'sponsorship_level_title', with: 'Gold'
 
diff --git a/spec/features/ticket_purchases_spec.rb b/spec/features/ticket_purchases_spec.rb
index 9cace981..8b675557 100644
--- a/spec/features/ticket_purchases_spec.rb
+++ b/spec/features/ticket_purchases_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Registration do
@@ -18,7 +20,6 @@ feature Registration do
     end
 
     context 'who is not registered' do
-
       scenario 'purchases and pays for a ticket succcessfully', feature: true, js: true do
         visit root_path
         click_link 'Register'
@@ -143,7 +144,6 @@ feature Registration do
     end
 
     context 'who is registered' do
-
       scenario 'unregisters from conference, but ticket purchases dont delete', feature: true, js: true do
         visit root_path
         click_link 'Register'
diff --git a/spec/features/tickets_spec.rb b/spec/features/tickets_spec.rb
index ab513cd1..3aae729f 100644
--- a/spec/features/tickets_spec.rb
+++ b/spec/features/tickets_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Ticket do
diff --git a/spec/features/track_organizer_ability_spec.rb b/spec/features/track_organizer_ability_spec.rb
index 67e0c8de..876b254a 100644
--- a/spec/features/track_organizer_ability_spec.rb
+++ b/spec/features/track_organizer_ability_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
-
   let(:organization) { create(:organization) }
   let(:conference) { create(:full_conference, organization: organization) }
   let(:self_organized_track) { create(:track, :self_organized, program: conference.program, state: 'confirmed') }
diff --git a/spec/features/tracks_spec.rb b/spec/features/tracks_spec.rb
index f753abc2..3d4916bc 100644
--- a/spec/features/tracks_spec.rb
+++ b/spec/features/tracks_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Track do
@@ -8,7 +10,6 @@ feature Track do
 
   shared_examples 'admin tracks' do
     scenario 'adds a track', feature: true, js: true do
-
       sign_in organizer
 
       expected = expect do
@@ -78,7 +79,6 @@ feature Track do
 
   shared_examples 'non admin tracks' do
     scenario 'adds a track', feature: true, js: true do
-
       sign_in user
 
       expected = expect do
diff --git a/spec/features/user_ability_spec.rb b/spec/features/user_ability_spec.rb
index d56e7441..aa33ef9e 100644
--- a/spec/features/user_ability_spec.rb
+++ b/spec/features/user_ability_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Has correct abilities' do
-
   let(:organization) { create(:organization) }
   let(:conference) { create(:full_conference, organization: organization) } # user is cfp
   let(:user) { create(:user) }
diff --git a/spec/features/user_spec.rb b/spec/features/user_spec.rb
index 7294ec5c..385c17d9 100644
--- a/spec/features/user_spec.rb
+++ b/spec/features/user_spec.rb
@@ -1,9 +1,9 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature User do
-
   shared_examples 'admin ability' do
-
   end
 
   describe 'admin' do
diff --git a/spec/features/venues_spec.rb b/spec/features/venues_spec.rb
index 2931b6e8..771815e7 100644
--- a/spec/features/venues_spec.rb
+++ b/spec/features/venues_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Conference do
@@ -7,12 +9,12 @@ feature Conference do
 
   shared_examples 'venue' do
     scenario 'adds and updates venue' do
-
       sign_in organizer
 
       # create the venue
       visit admin_conference_venue_path(
-                conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
       click_link 'Create Venue'
       fill_in 'venue_name', with: 'Example University'
       fill_in 'venue_street', with: 'Example Street 42'
@@ -25,7 +27,7 @@ feature Conference do
               'sadipscing elitr, sed diam nonumy eirmod tempor'
       click_button 'Create Venue'
       expect(flash)
-          .to eq('Venue was successfully created.')
+        .to eq('Venue was successfully created.')
       venue = Conference.find(conference.id).venue
       expect(venue.name).to eq('Example University')
       expect(venue.street).to eq('Example Street 42')
@@ -42,7 +44,7 @@ feature Conference do
       fill_in 'venue_description', with: 'new'
       click_button 'Update Venue'
       expect(flash)
-          .to eq('Venue was successfully updated.')
+        .to eq('Venue was successfully updated.')
       venue.reload
       expect(venue.name).to eq('Example University new')
       expect(venue.website).to eq('www.example.com new')
@@ -53,5 +55,4 @@ feature Conference do
   describe 'organizer' do
     it_behaves_like 'venue'
   end
-
 end
diff --git a/spec/features/versions_spec.rb b/spec/features/versions_spec.rb
index 3030d2b1..ac0ef163 100644
--- a/spec/features/versions_spec.rb
+++ b/spec/features/versions_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Version' do
@@ -34,7 +36,7 @@ feature 'Version' do
 
   scenario 'display changes in cfp', feature: true, versioning: true, js: true do
     cfp = create(:cfp, program: conference.program)
-    cfp.update_attributes(start_date: (Time.zone.today + 1).strftime('%d/%m/%Y'), end_date: (Time.zone.today + 3).strftime('%d/%m/%Y'))
+    cfp.update(start_date: (Time.zone.today + 1).strftime('%d/%m/%Y'), end_date: (Time.zone.today + 3).strftime('%d/%m/%Y'))
     cfp_id = cfp.id
     cfp.destroy
 
@@ -46,7 +48,7 @@ feature 'Version' do
 
   scenario 'display changes in registration_period', feature: true, versioning: true, js: true do
     registration_period = create(:registration_period, conference: conference)
-    registration_period.update_attributes(start_date: (Time.zone.today + 1).strftime('%d/%m/%Y'), end_date: (Time.zone.today + 3).strftime('%d/%m/%Y'))
+    registration_period.update(start_date: (Time.zone.today + 1).strftime('%d/%m/%Y'), end_date: (Time.zone.today + 3).strftime('%d/%m/%Y'))
     registration_period_id = registration_period.id
     registration_period.destroy
 
@@ -59,7 +61,7 @@ feature 'Version' do
   scenario 'display changes in conference', feature: true, versioning: true, js: true do
     new_conference = create(:conference, title: 'Test Conference')
     organizer.add_role :organizer, new_conference
-    new_conference.update_attributes(title: 'New Con', short_title: 'NewCon')
+    new_conference.update(title: 'New Con', short_title: 'NewCon')
 
     visit admin_revision_history_path
     select '100', from: 'versionstable_length'
@@ -71,7 +73,7 @@ feature 'Version' do
 
   scenario 'display changes in event_type', feature: true, versioning: true, js: true do
     event_type = create(:event_type, program: conference.program, name: 'Discussion')
-    event_type.update_attributes(length: 90, maximum_abstract_length: 10000)
+    event_type.update(length: 90, maximum_abstract_length: 10_000)
     event_type_id = event_type.id
     event_type.destroy
 
@@ -83,7 +85,7 @@ feature 'Version' do
 
   scenario 'display changes in lodging', feature: true, versioning: true, js: true do
     lodging = create(:lodging, conference: conference, name: 'Hotel XYZ')
-    lodging.update_attributes(description: 'Nice view,close to venue', website_link: 'http://www.example.com')
+    lodging.update(description: 'Nice view,close to venue', website_link: 'http://www.example.com')
     lodging_id = lodging.id
     lodging.destroy
 
@@ -105,7 +107,7 @@ feature 'Version' do
   scenario 'display changes in room', feature: true, versioning: true, js: true do
     venue = create(:venue, conference: conference)
     room = create(:room, venue: venue, name: 'Auditorium')
-    room.update_attributes(size: 120)
+    room.update(size: 120)
     room_id = room.id
     room.destroy
 
@@ -118,7 +120,7 @@ feature 'Version' do
   scenario 'display changes in sponsor', feature: true, versioning: true, js: true do
     conference.sponsorship_levels << create_list(:sponsorship_level, 2, conference: conference)
     sponsor = create(:sponsor, conference: conference, name: 'SUSE', sponsorship_level: conference.sponsorship_levels.first)
-    sponsor.update_attributes(website_url: 'https://www.suse.com/company/history', sponsorship_level: conference.sponsorship_levels.second)
+    sponsor.update(website_url: 'https://www.suse.com/company/history', sponsorship_level: conference.sponsorship_levels.second)
     sponsor.destroy
     sponsor_id = sponsor.id
 
@@ -130,7 +132,7 @@ feature 'Version' do
 
   scenario 'display changes in sponsorship_level', feature: true, versioning: true, js: true do
     sponsorship_level = create(:sponsorship_level, conference: conference)
-    sponsorship_level.update_attributes(title: 'Gold')
+    sponsorship_level.update(title: 'Gold')
     sponsorship_level_id = sponsorship_level.id
     sponsorship_level.destroy
 
@@ -142,7 +144,7 @@ feature 'Version' do
 
   scenario 'display changes in ticket', feature: true, versioning: true, js: true do
     ticket = create(:ticket, conference: conference, title: 'Gold')
-    ticket.update_attributes(price: 50, description: 'Premium Ticket')
+    ticket.update(price: 50, description: 'Premium Ticket')
     ticket_id = ticket.id
     ticket.destroy
 
@@ -154,7 +156,7 @@ feature 'Version' do
 
   scenario 'display changes in track', feature: true, versioning: true, js: true do
     track = create(:track, program: conference.program, name: 'Distribution')
-    track.update_attributes(description: 'Events about Linux distributions')
+    track.update(description: 'Events about Linux distributions')
     track_id = track.id
     track.destroy
 
@@ -166,7 +168,7 @@ feature 'Version' do
 
   scenario 'display changes in venue', feature: true, versioning: true, js: true do
     venue = create(:venue, conference: conference, name: 'Example University')
-    venue.update_attributes(website: 'www.example.com new', description: 'Just another beautiful venue')
+    venue.update(website: 'www.example.com new', description: 'Just another beautiful venue')
     venue_id = venue.id
     venue.destroy
 
@@ -220,7 +222,7 @@ feature 'Version' do
 
   scenario 'display changes in difficulty levels', feature: true, versioning: true, js: true do
     difficulty_level = create(:difficulty_level, program: conference.program, title: 'Expert')
-    difficulty_level.update_attributes(description: 'Only for Experts')
+    difficulty_level.update(description: 'Only for Experts')
     difficulty_level_id = difficulty_level.id
     difficulty_level.destroy
 
@@ -271,7 +273,7 @@ feature 'Version' do
 
   scenario 'display changes in conference commercials', feature: true, versioning: true, js: true do
     conference_commercial = create(:conference_commercial, commercialable: conference)
-    conference_commercial.update_attributes(url: 'https://www.youtube.com/watch?v=VNkDJk5_9eU')
+    conference_commercial.update(url: 'https://www.youtube.com/watch?v=VNkDJk5_9eU')
     conference_commercial.destroy
 
     visit admin_revision_history_path
@@ -282,7 +284,7 @@ feature 'Version' do
 
   scenario 'display changes in event commercials', feature: true, versioning: true, js: true do
     event_commercial
-    event_commercial.update_attributes(url: 'https://www.youtube.com/watch?v=VNkDJk5_9eU')
+    event_commercial.update(url: 'https://www.youtube.com/watch?v=VNkDJk5_9eU')
     event_commercial.destroy
 
     visit admin_revision_history_path
@@ -340,7 +342,7 @@ feature 'Version' do
   end
 
   scenario 'display changes in email settings', feature: true, versioning: true, js: true do
-    conference.email_settings.update_attributes(registration_subject: 'xxxxx', registration_body: 'yyyyy', accepted_subject: 'zzzzz')
+    conference.email_settings.update(registration_subject: 'xxxxx', registration_body: 'yyyyy', accepted_subject: 'zzzzz')
 
     visit admin_revision_history_path
     expect(page).to have_text("Someone (probably via the console) updated registration body, registration subject and accepted subject
@@ -361,7 +363,7 @@ feature 'Version' do
     registration = Registration.create(user: organizer, conference: conference)
     event = create(:event, program: conference.program, title: 'My second event')
     EventsRegistration.create(registration: registration, event: event)
-    EventsRegistration.first.update_attributes(attended: true)
+    EventsRegistration.first.update(attended: true)
     EventsRegistration.last.destroy
     # Here registration is deleted to ensure the event registration related change still displays the asociated user's name
     registration.destroy
@@ -374,7 +376,7 @@ feature 'Version' do
 
   scenario 'display changes in target', feature: true, versioning: true, js: true do
     target = create(:target, conference: conference)
-    target.update_attributes(due_date: Date.today, target_count: 1000)
+    target.update(due_date: Date.today, target_count: 1000)
     target_id = target.id
     target.destroy
 
@@ -416,7 +418,7 @@ feature 'Version' do
 
   scenario 'display changes in campaign', feature: true, versioning: true, js: true do
     campaign = create(:campaign, conference: conference, name: 'Test Campaign', utm_campaign: 'campaign')
-    campaign.update_attributes(utm_source: 'source', utm_medium: 'medium', utm_term: 'term', utm_content: 'content')
+    campaign.update(utm_source: 'source', utm_medium: 'medium', utm_term: 'term', utm_content: 'content')
     campaign_id = campaign.id
     campaign.destroy
 
@@ -443,7 +445,7 @@ feature 'Version' do
 
   scenario 'display updates to user', feature: true, versioning: true, js: true do
     user = create(:user)
-    user.update_attributes(nickname: 'testnick', affiliation: 'openSUSE')
+    user.update(nickname: 'testnick', affiliation: 'openSUSE')
 
     visit admin_revision_history_path
     expect(page).to have_text("Someone (probably via the console) updated  nickname and affiliation of user #{user.name}")
diff --git a/spec/features/volunteers_spec.rb b/spec/features/volunteers_spec.rb
index a27ba0b1..6f267900 100644
--- a/spec/features/volunteers_spec.rb
+++ b/spec/features/volunteers_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature Conference do
@@ -9,41 +11,42 @@ feature Conference do
     scenario 'adds and updates vdays', feature: true, js: true do
       sign_in(organizer)
       visit admin_conference_volunteers_info_path(
-        conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
       check('Enable Volunteering')
       check('Use vdays')
-#       click_link 'Add vday'
-#       expect(page.all('div.nested-fields').count == 1).to be true
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
-#         select("#{Date.today.strftime('%Y')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
-#           select("#{Date.today.strftime('%B')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
-#           select("#{Date.today.strftime('%-d')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
-#           set('Example Person')
+      #       click_link 'Add vday'
+      #       expect(page.all('div.nested-fields').count == 1).to be true
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
+      #         select("#{Date.today.strftime('%Y')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
+      #           select("#{Date.today.strftime('%B')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
+      #           select("#{Date.today.strftime('%-d')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
+      #           set('Example Person')
       click_button 'Update Conference'
       expect(flash)
-      .to eq('Volunteering options were successfully updated.')
+        .to eq('Volunteering options were successfully updated.')
 
-#       # Validations
-#       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
-#         value).to eq("#{Date.today.strftime('%Y')}")
-#       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
-#         value).to eq("#{Date.today.month}")
-#       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
-#         value).to eq("#{Date.today.strftime('%-d')}")
-#       expect(
-#         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
-#         value).to eq('Example Person')
-#
-#       # Remove vday
-#       click_link 'Remove vday'
-#       expect(page.all('div.nested-fields').count == 0).to be true
+      #       # Validations
+      #       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
+      #         value).to eq("#{Date.today.strftime('%Y')}")
+      #       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
+      #         value).to eq("#{Date.today.month}")
+      #       expect(find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
+      #         value).to eq("#{Date.today.strftime('%-d')}")
+      #       expect(
+      #         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
+      #         value).to eq('Example Person')
+      #
+      #       # Remove vday
+      #       click_link 'Remove vday'
+      #       expect(page.all('div.nested-fields').count == 0).to be true
       click_button 'Update Conference'
       expect(flash).to eq('Volunteering options were successfully updated.')
       expect(page.all('div.nested-fields').count == 0).to be true
@@ -53,65 +56,66 @@ feature Conference do
     scenario 'adds and updates vpositions', feature: true, js: true do
       sign_in(organizer)
       visit admin_conference_volunteers_info_path(
-        conference_id: conference.short_title)
+        conference_id: conference.short_title
+      )
 
       # Adding vday
       check('Enable Volunteering')
       check('Use vdays')
-#       click_link 'Add vday'
-#       expect(page.all('div.nested-fields').count == 1).to be true
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
-#           select("#{Date.today.strftime('%Y')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
-#         select("#{Date.today.strftime('%B')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
-#         select("#{Date.today.strftime('%-d')}")
-#       page.
-#         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
-#         set('Example Person')
+      #       click_link 'Add vday'
+      #       expect(page.all('div.nested-fields').count == 1).to be true
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(1)').
+      #           select("#{Date.today.strftime('%Y')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(2)').
+      #         select("#{Date.today.strftime('%B')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) select:nth-of-type(3)').
+      #         select("#{Date.today.strftime('%-d')}")
+      #       page.
+      #         find('div.nested-fields:nth-of-type(1) div:nth-of-type(1) textarea').
+      #         set('Example Person')
       click_button 'Update Conference'
       expect(flash)
-      .to eq('Volunteering options were successfully updated.')
+        .to eq('Volunteering options were successfully updated.')
 
       # Add vposition
       check('Use vpositions')
-#       click_link 'Add vposition'
-#       expect(page.all('div.nested-fields').count == 2).to be true
-#       page.find('div.vpositions div.nested-fields:nth-of-type(1)'\
-#                 ' div:nth-of-type(1) input').
-#                     set('Example Position')
-#       page.find('div.vpositions div.nested-fields:nth-of-type(1)'\
-#                 ' div:nth-of-type(2) textarea').
-#                     set('Example Description')
-#       find(:css, "select[id^='conference_vpositions_attributes_']"\
-#                  "[id$='_vday_ids']").
-#                       find(:option, "#{Date.today.strftime}").select_option
+      #       click_link 'Add vposition'
+      #       expect(page.all('div.nested-fields').count == 2).to be true
+      #       page.find('div.vpositions div.nested-fields:nth-of-type(1)'\
+      #                 ' div:nth-of-type(1) input').
+      #                     set('Example Position')
+      #       page.find('div.vpositions div.nested-fields:nth-of-type(1)'\
+      #                 ' div:nth-of-type(2) textarea').
+      #                     set('Example Description')
+      #       find(:css, "select[id^='conference_vpositions_attributes_']"\
+      #                  "[id$='_vday_ids']").
+      #                       find(:option, "#{Date.today.strftime}").select_option
       click_button 'Update Conference'
       expect(flash)
-      .to eq('Volunteering options were successfully updated.')
+        .to eq('Volunteering options were successfully updated.')
 
       # Validations
-#       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
-#                   ' div:nth-of-type(1) input').
-#                       value).to eq('Example Position')
-#       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
-#                   ' div:nth-of-type(2) textarea').
-#                       value).to eq('Example Description')
-#
-#       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
-#                   ' div:nth-of-type(3) select:nth-of-type(1)').find('option[selected]').
-#                       text).to eq(Date.today.strftime)
+      #       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
+      #                   ' div:nth-of-type(1) input').
+      #                       value).to eq('Example Position')
+      #       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
+      #                   ' div:nth-of-type(2) textarea').
+      #                       value).to eq('Example Description')
+      #
+      #       expect(find('div.vpositions div.nested-fields:nth-of-type(1)'\
+      #                   ' div:nth-of-type(3) select:nth-of-type(1)').find('option[selected]').
+      #                       text).to eq(Date.today.strftime)
 
       # Remove vposition
-#       click_link 'Remove vposition'
-#       expect(page.all('div.nested-fields').count == 1).to be true
-#       click_button 'Update Conference'
+      #       click_link 'Remove vposition'
+      #       expect(page.all('div.nested-fields').count == 1).to be true
+      #       click_button 'Update Conference'
       expect(flash).to eq('Volunteering options were successfully updated.')
-#       click_link 'Remove vday'
-#       expect(page.all('div.nested-fields').count == 0).to be true
+      #       click_link 'Remove vday'
+      #       expect(page.all('div.nested-fields').count == 0).to be true
       sign_out
     end
   end
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index ff0fbfa2..4222c079 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ApplicationHelper, type: :helper do
@@ -27,7 +29,7 @@ describe ApplicationHelper, type: :helper do
     before :each do
       @other_event = create(:event, program: conference.program, state: 'confirmed')
       schedule = create(:schedule, program: conference.program)
-      conference.program.update_attributes!(selected_schedule: schedule)
+      conference.program.update!(selected_schedule: schedule)
       @event_schedule = create(:event_schedule, event: event, start_time: conference.start_date + conference.start_hour.hours, room: create(:room), schedule: schedule)
       @other_event_schedule = create(:event_schedule, event: @other_event, start_time: conference.start_date + conference.start_hour.hours, room: create(:room), schedule: schedule)
     end
@@ -38,7 +40,7 @@ describe ApplicationHelper, type: :helper do
       end
 
       it 'when event is in between the other event' do
-        @event_schedule.update_attributes!(start_time: @other_event_schedule.start_time + 10.minutes)
+        @event_schedule.update!(start_time: @other_event_schedule.start_time + 10.minutes)
         expect(concurrent_events(event).include?(@other_event)).to eq true
       end
     end
@@ -50,12 +52,12 @@ describe ApplicationHelper, type: :helper do
       end
 
       it 'when one event starts and other ends at the same time' do
-        @event_schedule.update_attributes!(start_time: @other_event_schedule.end_time)
+        @event_schedule.update!(start_time: @other_event_schedule.end_time)
         expect(concurrent_events(event).present?).to eq false
       end
 
       it 'when conference program does not have a selected schedule' do
-        conference.program.update_attributes!(selected_schedule_id: nil)
+        conference.program.update!(selected_schedule_id: nil)
         expect(concurrent_events(event).present?).to eq false
       end
     end
@@ -81,7 +83,7 @@ describe ApplicationHelper, type: :helper do
     context 'first sponsorship_level' do
       before do
         first_sponsorship_level = create(:sponsorship_level, position: 1)
-        sponsor.update_attributes(sponsorship_level: first_sponsorship_level)
+        sponsor.update(sponsorship_level: first_sponsorship_level)
       end
 
       it 'returns correct url' do
@@ -92,7 +94,7 @@ describe ApplicationHelper, type: :helper do
     context 'second sponsorship_level' do
       before do
         second_sponsorship_level = create(:sponsorship_level, position: 2)
-        sponsor.update_attributes(sponsorship_level: second_sponsorship_level)
+        sponsor.update(sponsorship_level: second_sponsorship_level)
       end
 
       it 'returns correct url' do
@@ -103,7 +105,7 @@ describe ApplicationHelper, type: :helper do
     context 'other sponsorship_level' do
       before do
         other_sponsorship_level = create(:sponsorship_level, position: 3)
-        sponsor.update_attributes(sponsorship_level: other_sponsorship_level)
+        sponsor.update(sponsorship_level: other_sponsorship_level)
       end
 
       it 'returns correct url' do
diff --git a/spec/helpers/conference_helper_spec.rb b/spec/helpers/conference_helper_spec.rb
index 09e38e69..101d083a 100644
--- a/spec/helpers/conference_helper_spec.rb
+++ b/spec/helpers/conference_helper_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ConferenceHelper, type: :helper do
diff --git a/spec/helpers/date_time_helper_spec.rb b/spec/helpers/date_time_helper_spec.rb
index 09c7e4a4..97029c4c 100644
--- a/spec/helpers/date_time_helper_spec.rb
+++ b/spec/helpers/date_time_helper_spec.rb
@@ -1,14 +1,15 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe DateTimeHelper, type: :helper do
-
   describe 'format_datetime' do
     it 'returns nothing if there is no parameter' do
       expect(format_datetime(nil)).to eq nil
     end
 
     it 'returns formatted string' do
-      datetime = Time.zone.local(2016, 05, 04, 11, 30)
+      datetime = Time.zone.local(2016, 0o5, 0o4, 11, 30)
       expect(format_datetime(datetime)).to eq '2016-05-04 11:30'
     end
   end
diff --git a/spec/helpers/events_helper_spec.rb b/spec/helpers/events_helper_spec.rb
index baefebbc..a77c336b 100644
--- a/spec/helpers/events_helper_spec.rb
+++ b/spec/helpers/events_helper_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe EventsHelper, type: :helper do
diff --git a/spec/helpers/format_helper_spec.rb b/spec/helpers/format_helper_spec.rb
index f14de8b3..a997cafe 100644
--- a/spec/helpers/format_helper_spec.rb
+++ b/spec/helpers/format_helper_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe FormatHelper, type: :helper do
-
   describe 'markdown' do
     it 'should return empty string for nil' do
       expect(markdown(nil)).to eq ''
@@ -9,8 +10,8 @@ describe FormatHelper, type: :helper do
 
     it 'should return HTML for header markdown' do
       expect(Redcarpet::Markdown).to receive(:new)
-      .with(Redcarpet::Render::HTML, autolink: true, space_after_headers: true, no_intra_emphasis: true)
-      .and_call_original
+        .with(Redcarpet::Render::HTML, autolink: true, space_after_headers: true, no_intra_emphasis: true)
+        .and_call_original
 
       expect(markdown('# this is my header')).to eq "<h1>this is my header</h1>\n"
     end
diff --git a/spec/helpers/users_helper_spec.rb b/spec/helpers/users_helper_spec.rb
index e0c2d3fd..19f177cc 100644
--- a/spec/helpers/users_helper_spec.rb
+++ b/spec/helpers/users_helper_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe UsersHelper, type: :helper do
-
   describe 'show_roles' do
     it 'formats the hash passed' do
       roles = { 'organizer' => %w[oSC16 oSC15], 'cfp' => ['oSC16'] }
diff --git a/spec/mailers/mailbot_spec.rb b/spec/mailers/mailbot_spec.rb
index 76c6ef00..efb521c8 100644
--- a/spec/mailers/mailbot_spec.rb
+++ b/spec/mailers/mailbot_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Mailbot do
@@ -5,7 +7,7 @@ describe Mailbot do
   let!(:email_settings) { create(:email_settings, conference: conference) }
   let(:user) { create(:user, email: 'user@example.com') }
 
-  before { conference.contact.update_attributes(email: 'conf@domain.com') }
+  before { conference.contact.update(email: 'conf@domain.com') }
 
   context 'onboarding and proposal' do
     let(:event) { create(:event, program: conference.program, submitter: user) }
@@ -37,9 +39,9 @@ describe Mailbot do
 
     describe '.acceptance_mail' do
       before do
-        conference.email_settings.update_attributes(send_on_accepted: true,
-                                                    accepted_subject: 'Lorem Ipsum Dolsum',
-                                                    accepted_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
+        conference.email_settings.update(send_on_accepted: true,
+                                         accepted_subject: 'Lorem Ipsum Dolsum',
+                                         accepted_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
       end
 
       include_examples 'mailer actions' do
@@ -49,9 +51,9 @@ describe Mailbot do
 
     describe '.rejection_mail' do
       before do
-        conference.email_settings.update_attributes(send_on_rejected: true,
-                                                    rejected_subject: 'Lorem Ipsum Dolsum',
-                                                    rejected_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
+        conference.email_settings.update(send_on_rejected: true,
+                                         rejected_subject: 'Lorem Ipsum Dolsum',
+                                         rejected_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
       end
 
       include_examples 'mailer actions' do
@@ -61,9 +63,9 @@ describe Mailbot do
 
     describe '.confirm_reminder_mail' do
       before do
-        conference.email_settings.update_attributes(send_on_confirmed_without_registration: true,
-                                                    confirmed_without_registration_subject: 'Lorem Ipsum Dolsum',
-                                                    confirmed_without_registration_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
+        conference.email_settings.update(send_on_confirmed_without_registration: true,
+                                         confirmed_without_registration_subject: 'Lorem Ipsum Dolsum',
+                                         confirmed_without_registration_body: 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit')
       end
 
       include_examples 'mailer actions' do
diff --git a/spec/models/ability_spec.rb b/spec/models/ability_spec.rb
index 26522913..084c2aee 100644
--- a/spec/models/ability_spec.rb
+++ b/spec/models/ability_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 require 'cancan/matchers'
 
@@ -6,8 +8,8 @@ describe 'User' do
     let!(:admin) { create(:admin) }
 
     # see https://github.com/CanCanCommunity/cancancan/wiki/Testing-Abilities
-    subject(:ability){ Ability.new(user) }
-    let(:user){ nil }
+    subject(:ability) { Ability.new(user) }
+    let(:user) { nil }
 
     let!(:organization) { create(:organization) }
     let!(:my_conference) { create(:full_conference, organization: organization) }
@@ -34,41 +36,41 @@ describe 'User' do
 
     # Test abilities for not signed in users
     context 'when user is not signed in' do
-      it{ should be_able_to(:index, Organization)}
-      it{ should be_able_to(:index, Conference)}
+      it { should be_able_to(:index, Organization) }
+      it { should be_able_to(:index, Conference) }
 
-      it{ should be_able_to(:show, conference_public)}
-      it{ should_not be_able_to(:show, conference_not_public)}
+      it { should be_able_to(:show, conference_public) }
+      it { should_not be_able_to(:show, conference_not_public) }
 
       it do
         conference_public.program.schedule_public = true
         conference_public.program.save
         should be_able_to(:schedule, conference_public)
       end
-      it{ should_not be_able_to(:schedule, conference_not_public)}
+      it { should_not be_able_to(:schedule, conference_not_public) }
 
-      it{ should be_able_to(:show, event_confirmed)}
-      it{ should_not be_able_to(:show, event_unconfirmed)}
+      it { should be_able_to(:show, event_confirmed) }
+      it { should_not be_able_to(:show, event_unconfirmed) }
 
-      it{ should be_able_to(:show, commercial_event_confirmed)}
-      it{ should_not be_able_to(:show, commercial_event_unconfirmed)}
+      it { should be_able_to(:show, commercial_event_confirmed) }
+      it { should_not be_able_to(:show, commercial_event_unconfirmed) }
 
-      it{ should be_able_to(:show, User)}
-      it{ should be_able_to(:create, User)}
+      it { should be_able_to(:show, User) }
+      it { should be_able_to(:create, User) }
 
-      it{ should be_able_to(:show, Registration.new)}
-      it{ should be_able_to(:create, Registration.new(conference_id: conference_with_open_registration.id))}
-      it{ should be_able_to(:new, Registration.new(conference_id: conference_with_open_registration.id))}
-      it{ should_not be_able_to(:new, Registration.new(conference_id: conference_with_closed_registration.id))}
-      it{ should_not be_able_to(:create, Registration.new(conference_id: conference_with_closed_registration.id))}
-      it{ should_not be_able_to(:manage, registration)}
+      it { should be_able_to(:show, Registration.new) }
+      it { should be_able_to(:create, Registration.new(conference_id: conference_with_open_registration.id)) }
+      it { should be_able_to(:new, Registration.new(conference_id: conference_with_open_registration.id)) }
+      it { should_not be_able_to(:new, Registration.new(conference_id: conference_with_closed_registration.id)) }
+      it { should_not be_able_to(:create, Registration.new(conference_id: conference_with_closed_registration.id)) }
+      it { should_not be_able_to(:manage, registration) }
 
-      it{ should be_able_to(:new, Event.new(program: program_with_cfp)) }
-      it{ should_not be_able_to(:new, Event.new(program: program_without_cfp)) }
-      it{ should_not be_able_to(:create, Event.new(program: program_without_cfp))}
-      it{ should be_able_to(:show, Event.new)}
+      it { should be_able_to(:new, Event.new(program: program_with_cfp)) }
+      it { should_not be_able_to(:new, Event.new(program: program_without_cfp)) }
+      it { should_not be_able_to(:create, Event.new(program: program_without_cfp)) }
+      it { should be_able_to(:show, Event.new) }
 
-      it{ should_not be_able_to(:manage, :any)}
+      it { should_not be_able_to(:manage, :any) }
     end
 
     # Test abilities for signed in users (without any role)
@@ -88,9 +90,9 @@ describe 'User' do
       let(:confirmed_user_self_organized_track) { create(:track, :self_organized, submitter: user, state: 'confirmed') }
       let(:other_self_organized_track) { create(:track, :self_organized) }
 
-      it{ should be_able_to(:manage, user) }
-      it{ should be_able_to(:manage, registration_public) }
-      it{ should be_able_to(:manage, registration_not_public) }
+      it { should be_able_to(:manage, user) }
+      it { should be_able_to(:manage, registration_public) }
+      it { should be_able_to(:manage, registration_not_public) }
 
       # Test for user can register or not
       context 'when user is not a speaker with event confirmed' do
@@ -101,13 +103,13 @@ describe 'User' do
             create(:registration_period, conference: conference, start_date: Date.current - 6.days, end_date: Date.current - 6.days)
           end
 
-          it{ should_not be_able_to(:new, Registration.new(conference: conference)) }
-          it{ should_not be_able_to(:create, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:new, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:create, Registration.new(conference: conference)) }
         end
 
         context 'when the registration period is not set' do
-          it{ should_not be_able_to(:new, Registration.new(conference: conference)) }
-          it{ should_not be_able_to(:create, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:new, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:create, Registration.new(conference: conference)) }
         end
 
         context 'when user has already registered' do
@@ -115,8 +117,8 @@ describe 'User' do
             create(:registration, conference: conference, user: user)
           end
 
-          it{ should_not be_able_to(:new, Registration.new(conference: conference)) }
-          it{ should_not be_able_to(:create, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:new, Registration.new(conference: conference)) }
+          it { should_not be_able_to(:create, Registration.new(conference: conference)) }
         end
 
         context 'when registrations are open' do
@@ -124,16 +126,16 @@ describe 'User' do
             create(:registration_period, conference: conference)
           end
 
-          it{ should be_able_to(:new, Registration.new(conference: conference)) }
-          it{ should be_able_to(:create, Registration.new(conference: conference)) }
+          it { should be_able_to(:new, Registration.new(conference: conference)) }
+          it { should be_able_to(:create, Registration.new(conference: conference)) }
 
           context 'when user has not registered with no registration_limit_exceeded' do
             before :each do
               conference.registration_limit = 1
             end
 
-            it{ should be_able_to(:new, Registration.new(conference: conference)) }
-            it{ should be_able_to(:create, Registration.new(conference: conference)) }
+            it { should be_able_to(:new, Registration.new(conference: conference)) }
+            it { should be_able_to(:create, Registration.new(conference: conference)) }
           end
 
           context 'when user has not registered with registration_limit_exceeded' do
@@ -142,8 +144,8 @@ describe 'User' do
               create(:registration, conference: conference, user: user2)
             end
 
-            it{ should_not be_able_to(:new, Registration.new(conference: conference)) }
-            it{ should_not be_able_to(:create, Registration.new(conference: conference)) }
+            it { should_not be_able_to(:new, Registration.new(conference: conference)) }
+            it { should_not be_able_to(:create, Registration.new(conference: conference)) }
           end
         end
       end
@@ -157,8 +159,8 @@ describe 'User' do
         end
 
         context 'when registration period is not set' do
-          it{ should_not be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-          it{ should_not be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+          it { should_not be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+          it { should_not be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
         end
 
         context 'when speaker has already registered' do
@@ -166,8 +168,8 @@ describe 'User' do
             create(:registration, conference: conference_with_speaker_confirmed, user: user)
           end
 
-          it{ should_not be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-          it{ should_not be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+          it { should_not be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+          it { should_not be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
         end
 
         context 'when registration period is set' do
@@ -177,8 +179,8 @@ describe 'User' do
 
           context 'when registrations are open' do
             context 'when speaker has not registered' do
-              it{ should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-              it{ should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
             end
 
             context 'when registration_limit_exceeded' do
@@ -187,8 +189,8 @@ describe 'User' do
                 create(:registration, conference: conference_with_speaker_confirmed, user: user2)
               end
 
-              it{ should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-              it{ should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
             end
           end
 
@@ -198,8 +200,8 @@ describe 'User' do
             end
 
             context 'when speaker has not registered' do
-              it{ should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-              it{ should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
             end
 
             context 'with registration_limit_exceeded' do
@@ -208,61 +210,61 @@ describe 'User' do
                 create(:registration, conference: conference_with_speaker_confirmed, user: user2)
               end
 
-              it{ should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
-              it{ should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:new, Registration.new(conference: conference_with_speaker_confirmed)) }
+              it { should be_able_to(:create, Registration.new(conference: conference_with_speaker_confirmed)) }
             end
           end
         end
       end
 
-      it{ should be_able_to(:index, Ticket) }
-      it{ should be_able_to(:manage, TicketPurchase.new(user_id: user.id)) }
+      it { should be_able_to(:index, Ticket) }
+      it { should be_able_to(:manage, TicketPurchase.new(user_id: user.id)) }
 
-      it{ should be_able_to(:new, Payment.new(user_id: user.id)) }
-      it{ should be_able_to(:create, Payment.new(user_id: user.id)) }
+      it { should be_able_to(:new, Payment.new(user_id: user.id)) }
+      it { should be_able_to(:create, Payment.new(user_id: user.id)) }
 
-      it{ should be_able_to(:create, Subscription.new(user_id: user.id)) }
-      it{ should be_able_to(:destroy, subscription) }
+      it { should be_able_to(:create, Subscription.new(user_id: user.id)) }
+      it { should be_able_to(:destroy, subscription) }
 
-      it{ should be_able_to(:update, user_event_with_cfp) }
-      it{ should be_able_to(:show, user_event_with_cfp) }
-      it{ should_not be_able_to(:new, Event.new(program: program_without_cfp)) }
-      it{ should_not be_able_to(:create, Event.new(program: program_without_cfp)) }
+      it { should be_able_to(:update, user_event_with_cfp) }
+      it { should be_able_to(:show, user_event_with_cfp) }
+      it { should_not be_able_to(:new, Event.new(program: program_without_cfp)) }
+      it { should_not be_able_to(:create, Event.new(program: program_without_cfp)) }
       # TODO: At moment it's not possible to manually add someone else as event_user
       # This needs some more work once we allow user to add event_user
       it 'should_not be_able to :new, Event.new(program: program_with_cfp, event_users: [event_user2])'
       it 'should_not be_able to :create, Event.new(program: program_with_cfp, event_users: [event_user2])'
 
-      it{ should_not be_able_to(:manage, event_unconfirmed) }
+      it { should_not be_able_to(:manage, event_unconfirmed) }
 
-      it{ should be_able_to(:create, user_event_with_cfp.commercials.new) }
-      it{ should be_able_to(:manage, user_commercial) }
-      it{ should_not be_able_to(:manage, commercial_event_unconfirmed) }
+      it { should be_able_to(:create, user_event_with_cfp.commercials.new) }
+      it { should be_able_to(:manage, user_commercial) }
+      it { should_not be_able_to(:manage, commercial_event_unconfirmed) }
 
-      it{ should be_able_to(:new, Track.new(program: program_with_call_for_tracks)) }
-      it{ should be_able_to(:create, Track.new(program: program_with_call_for_tracks)) }
-      it{ should_not be_able_to(:new, Track.new(program: program_without_cfp)) }
-      it{ should_not be_able_to(:create, Track.new(program: program_without_cfp)) }
+      it { should be_able_to(:new, Track.new(program: program_with_call_for_tracks)) }
+      it { should be_able_to(:create, Track.new(program: program_with_call_for_tracks)) }
+      it { should_not be_able_to(:new, Track.new(program: program_without_cfp)) }
+      it { should_not be_able_to(:create, Track.new(program: program_without_cfp)) }
 
-      it{ should be_able_to(:index, user_self_organized_track) }
-      it{ should be_able_to(:show, user_self_organized_track) }
-      it{ should be_able_to(:restart, user_self_organized_track) }
-      it{ should be_able_to(:confirm, user_self_organized_track) }
-      it{ should be_able_to(:withdraw, user_self_organized_track) }
-      it{ should_not be_able_to(:index, other_self_organized_track) }
-      it{ should_not be_able_to(:show, other_self_organized_track) }
-      it{ should_not be_able_to(:restart, other_self_organized_track) }
-      it{ should_not be_able_to(:confirm, other_self_organized_track) }
-      it{ should_not be_able_to(:withdraw, other_self_organized_track) }
+      it { should be_able_to(:index, user_self_organized_track) }
+      it { should be_able_to(:show, user_self_organized_track) }
+      it { should be_able_to(:restart, user_self_organized_track) }
+      it { should be_able_to(:confirm, user_self_organized_track) }
+      it { should be_able_to(:withdraw, user_self_organized_track) }
+      it { should_not be_able_to(:index, other_self_organized_track) }
+      it { should_not be_able_to(:show, other_self_organized_track) }
+      it { should_not be_able_to(:restart, other_self_organized_track) }
+      it { should_not be_able_to(:confirm, other_self_organized_track) }
+      it { should_not be_able_to(:withdraw, other_self_organized_track) }
 
-      it{ should be_able_to(:edit, user_self_organized_track) }
-      it{ should be_able_to(:update, user_self_organized_track) }
-      it{ should_not be_able_to(:edit, accepted_user_self_organized_track) }
-      it{ should_not be_able_to(:update, accepted_user_self_organized_track) }
-      it{ should_not be_able_to(:edit, confirmed_user_self_organized_track) }
-      it{ should_not be_able_to(:update, confirmed_user_self_organized_track) }
-      it{ should_not be_able_to(:edit, other_self_organized_track) }
-      it{ should_not be_able_to(:update, other_self_organized_track) }
+      it { should be_able_to(:edit, user_self_organized_track) }
+      it { should be_able_to(:update, user_self_organized_track) }
+      it { should_not be_able_to(:edit, accepted_user_self_organized_track) }
+      it { should_not be_able_to(:update, accepted_user_self_organized_track) }
+      it { should_not be_able_to(:edit, confirmed_user_self_organized_track) }
+      it { should_not be_able_to(:update, confirmed_user_self_organized_track) }
+      it { should_not be_able_to(:edit, other_self_organized_track) }
+      it { should_not be_able_to(:update, other_self_organized_track) }
     end
   end
 end
diff --git a/spec/models/admin_ability_spec.rb b/spec/models/admin_ability_spec.rb
index 344f63ba..6231b002 100644
--- a/spec/models/admin_ability_spec.rb
+++ b/spec/models/admin_ability_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 require 'cancan/matchers'
 
@@ -6,8 +8,8 @@ describe 'User with admin role' do
     let!(:admin) { create(:admin) }
 
     # see https://github.com/CanCanCommunity/cancancan/wiki/Testing-Abilities
-    subject(:ability){ AdminAbility.new(user) }
-    let(:user){ nil }
+    subject(:ability) { AdminAbility.new(user) }
+    let(:user) { nil }
 
     let!(:organization) { create(:organization) }
     let!(:my_conference) { create(:full_conference, organization: organization) }
@@ -52,29 +54,29 @@ describe 'User with admin role' do
       let(:room) { create(:room, venue: venue) }
       let!(:event) { create(:event_full, program: my_conference.program, room_id: room.id) }
       let(:user) { create(:admin) }
-      it{ should be_able_to(:manage, :all) }
-      it{ should_not be_able_to(:destroy, my_conference.program) }
-      it{ should_not be_able_to(:destroy, my_venue) }
+      it { should be_able_to(:manage, :all) }
+      it { should_not be_able_to(:destroy, my_conference.program) }
+      it { should_not be_able_to(:destroy, my_venue) }
     end
 
     shared_examples 'user with any role' do
       let!(:other_organization) { create(:organization) }
       let!(:other_conference) { create(:conference, organization: other_organization) }
 
-      it{ should_not be_able_to(:update, Role.find_by(name: 'organization_admin', resource: other_organization)) }
-      it{ should_not be_able_to(:edit, Role.find_by(name: 'organization_admin', resource: other_organization)) }
-      it{ should be_able_to(:admins, organization) }
+      it { should_not be_able_to(:update, Role.find_by(name: 'organization_admin', resource: other_organization)) }
+      it { should_not be_able_to(:edit, Role.find_by(name: 'organization_admin', resource: other_organization)) }
+      it { should be_able_to(:admins, organization) }
 
-      it{ should_not be_able_to(:new, User.new) }
-      it{ should_not be_able_to(:create, User.new) }
-      it{ should_not be_able_to(:manage, User) }
+      it { should_not be_able_to(:new, User.new) }
+      it { should_not be_able_to(:create, User.new) }
+      it { should_not be_able_to(:manage, User) }
 
       %w[organizer cfp info_desk volunteers_coordinator].each do |role|
-        it{ should_not be_able_to(:toggle_user, Role.find_by(name: role, resource: other_conference)) }
-        it{ should_not be_able_to(:update, Role.find_by(name: role, resource: other_conference)) }
-        it{ should_not be_able_to(:edit, Role.find_by(name: role, resource: other_conference)) }
-        it{ should be_able_to(:show, Role.find_by(name: role, resource: other_conference)) }
-        it{ should be_able_to(:index, Role.find_by(name: role, resource: other_conference)) }
+        it { should_not be_able_to(:toggle_user, Role.find_by(name: role, resource: other_conference)) }
+        it { should_not be_able_to(:update, Role.find_by(name: role, resource: other_conference)) }
+        it { should_not be_able_to(:edit, Role.find_by(name: role, resource: other_conference)) }
+        it { should be_able_to(:show, Role.find_by(name: role, resource: other_conference)) }
+        it { should be_able_to(:index, Role.find_by(name: role, resource: other_conference)) }
       end
 
       context 'accesses track organizers' do
@@ -83,25 +85,25 @@ describe 'User with admin role' do
           @other_track_organizer_role = Role.where(name: 'track_organizer', resource: other_self_organized_track).first_or_create
         end
 
-        it{ should_not be_able_to(:toggle_user, @other_track_organizer_role) }
-        it{ should_not be_able_to(:update, @other_track_organizer_role) }
-        it{ should_not be_able_to(:edit, @other_track_organizer_role) }
-        it{ should be_able_to(:show, @other_track_organizer_role) }
-        it{ should be_able_to(:index, @other_track_organizer_role) }
+        it { should_not be_able_to(:toggle_user, @other_track_organizer_role) }
+        it { should_not be_able_to(:update, @other_track_organizer_role) }
+        it { should_not be_able_to(:edit, @other_track_organizer_role) }
+        it { should be_able_to(:show, @other_track_organizer_role) }
+        it { should be_able_to(:index, @other_track_organizer_role) }
       end
     end
 
     shared_examples 'user with non-organizer role' do |role_name|
       %w[organizer cfp info_desk volunteers_coordinator].each do |role|
         if role == role_name
-          it{ should be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
+          it { should be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
         else
-          it{ should_not be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
+          it { should_not be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
         end
-        it{ should_not be_able_to(:update, Role.find_by(name: role, resource: my_conference)) }
-        it{ should_not be_able_to(:edit, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:show, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:index, Role.find_by(name: role, resource: my_conference)) }
+        it { should_not be_able_to(:update, Role.find_by(name: role, resource: my_conference)) }
+        it { should_not be_able_to(:edit, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:show, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:index, Role.find_by(name: role, resource: my_conference)) }
       end
 
       context 'accesses track organizers' do
@@ -110,14 +112,14 @@ describe 'User with admin role' do
         end
 
         if role_name == 'track_organizer'
-          it{ should be_able_to(:toggle_user, @track_organizer_role) }
+          it { should be_able_to(:toggle_user, @track_organizer_role) }
         else
-          it{ should_not be_able_to(:toggle_user, @track_organizer_role) }
+          it { should_not be_able_to(:toggle_user, @track_organizer_role) }
         end
-        it{ should_not be_able_to(:update, @track_organizer_role) }
-        it{ should_not be_able_to(:edit, @track_organizer_role) }
-        it{ should be_able_to(:show, @track_organizer_role) }
-        it{ should be_able_to(:index, @track_organizer_role) }
+        it { should_not be_able_to(:update, @track_organizer_role) }
+        it { should_not be_able_to(:edit, @track_organizer_role) }
+        it { should be_able_to(:show, @track_organizer_role) }
+        it { should be_able_to(:index, @track_organizer_role) }
       end
     end
 
@@ -127,18 +129,18 @@ describe 'User with admin role' do
       let(:other_organization) { create(:organization) }
       let(:other_conference) { create(:conference, organization: other_organization) }
 
-      it{ should be_able_to(:assign_org_admins, organization) }
-      it{ should be_able_to(:unassign_org_admins, organization) }
-      it{ should be_able_to(:manage, my_conference) }
-      it{ should be_able_to(:read, organization) }
-      it{ should be_able_to(:update, organization) }
-      it{ should be_able_to(:destroy, organization) }
-      it{ should be_able_to(:new, Conference.new) }
-      it{ should be_able_to(:create, Conference.new(organization_id: organization.id)) }
-      it{ should_not be_able_to(:manage, other_conference) }
-      it{ should_not be_able_to(:create, Conference.new(organization_id: other_organization.id)) }
-      it{ should_not be_able_to(:new, Organization.new) }
-      it{ should_not be_able_to(:create, Organization.new) }
+      it { should be_able_to(:assign_org_admins, organization) }
+      it { should be_able_to(:unassign_org_admins, organization) }
+      it { should be_able_to(:manage, my_conference) }
+      it { should be_able_to(:read, organization) }
+      it { should be_able_to(:update, organization) }
+      it { should be_able_to(:destroy, organization) }
+      it { should be_able_to(:new, Conference.new) }
+      it { should be_able_to(:create, Conference.new(organization_id: organization.id)) }
+      it { should_not be_able_to(:manage, other_conference) }
+      it { should_not be_able_to(:create, Conference.new(organization_id: other_organization.id)) }
+      it { should_not be_able_to(:new, Organization.new) }
+      it { should_not be_able_to(:create, Organization.new) }
 
       it_behaves_like 'user with any role'
     end
@@ -147,7 +149,7 @@ describe 'User with admin role' do
       let(:role) { Role.find_by(name: 'organizer', resource: my_conference) }
       let(:user) { create(:user, role_ids: [role.id]) }
 
-      it{ should_not be_able_to(:destroy, my_conference.program) }
+      it { should_not be_able_to(:destroy, my_conference.program) }
       it 'when there is a room assigned to an event' do
         should_not be_able_to(:destroy, my_venue)
       end
@@ -159,74 +161,74 @@ describe 'User with admin role' do
         should be_able_to(:destroy, my_venue)
       end
 
-      it{ should_not be_able_to(:new, Organization.new) }
-      it{ should_not be_able_to(:create, Organization.new) }
-      it{ should_not be_able_to(:new, Conference.new) }
-      it{ should_not be_able_to(:create, Conference.new) }
-      it{ should be_able_to(:read, my_conference) }
-      it{ should be_able_to(:update, my_conference) }
-      it{ should be_able_to(:destroy, my_conference) }
-      it{ should_not be_able_to(:manage, conference_public) }
-      it{ should be_able_to(:manage, my_conference.splashpage) }
-      it{ should_not be_able_to(:manage, conference_public.splashpage) }
-      it{ should be_able_to(:manage, my_conference.contact) }
-      it{ should_not be_able_to(:manage, conference_public.contact) }
-      it{ should be_able_to(:manage, my_conference.email_settings) }
-      it{ should_not be_able_to(:manage, conference_public.email_settings) }
-      it{ should be_able_to(:manage, my_conference.campaigns.first) }
-      it{ should_not be_able_to(:manage, conference_public.campaigns.first) }
-      it{ should be_able_to(:manage, my_conference.targets.first) }
-      it{ should_not be_able_to(:manage, conference_public.targets.first) }
-      it{ should be_able_to(:manage, my_conference.commercials.first) }
-      it{ should_not be_able_to(:manage, conference_public.commercials.first) }
-      it{ should be_able_to(:manage, my_conference.registration_period) }
-      it{ should_not be_able_to(:manage, conference_public.registration_period) }
-      it{ should be_able_to(:manage, my_conference.questions.first) }
-      it{ should_not be_able_to(:manage, conference_public.questions.first) }
-      it{ should be_able_to(:manage, my_conference.program.cfp) }
-      it{ should_not be_able_to(:manage, conference_public.program.cfp) }
-      it{ should be_able_to(:manage, my_schedule) }
-      it{ should_not be_able_to(:manage, other_schedule) }
-      it{ should be_able_to(:manage, my_event_schedule) }
-      it{ should_not be_able_to(:manage, other_event_schedule) }
-      it{ should be_able_to(:manage, my_conference.venue) }
-      it{ should_not be_able_to(:manage, conference_public.venue) }
-      it{ should be_able_to(:manage, my_conference.lodgings.first) }
-      it{ should_not be_able_to(:manage, conference_public.lodgings.first) }
-      it{ should be_able_to(:manage, my_conference.sponsors.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsors.first) }
-      it{ should be_able_to(:manage, my_conference.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
-      it{ should be_able_to(:manage, my_conference.tickets.first) }
-      it{ should_not be_able_to(:manage, conference_public.tickets.first) }
+      it { should_not be_able_to(:new, Organization.new) }
+      it { should_not be_able_to(:create, Organization.new) }
+      it { should_not be_able_to(:new, Conference.new) }
+      it { should_not be_able_to(:create, Conference.new) }
+      it { should be_able_to(:read, my_conference) }
+      it { should be_able_to(:update, my_conference) }
+      it { should be_able_to(:destroy, my_conference) }
+      it { should_not be_able_to(:manage, conference_public) }
+      it { should be_able_to(:manage, my_conference.splashpage) }
+      it { should_not be_able_to(:manage, conference_public.splashpage) }
+      it { should be_able_to(:manage, my_conference.contact) }
+      it { should_not be_able_to(:manage, conference_public.contact) }
+      it { should be_able_to(:manage, my_conference.email_settings) }
+      it { should_not be_able_to(:manage, conference_public.email_settings) }
+      it { should be_able_to(:manage, my_conference.campaigns.first) }
+      it { should_not be_able_to(:manage, conference_public.campaigns.first) }
+      it { should be_able_to(:manage, my_conference.targets.first) }
+      it { should_not be_able_to(:manage, conference_public.targets.first) }
+      it { should be_able_to(:manage, my_conference.commercials.first) }
+      it { should_not be_able_to(:manage, conference_public.commercials.first) }
+      it { should be_able_to(:manage, my_conference.registration_period) }
+      it { should_not be_able_to(:manage, conference_public.registration_period) }
+      it { should be_able_to(:manage, my_conference.questions.first) }
+      it { should_not be_able_to(:manage, conference_public.questions.first) }
+      it { should be_able_to(:manage, my_conference.program.cfp) }
+      it { should_not be_able_to(:manage, conference_public.program.cfp) }
+      it { should be_able_to(:manage, my_schedule) }
+      it { should_not be_able_to(:manage, other_schedule) }
+      it { should be_able_to(:manage, my_event_schedule) }
+      it { should_not be_able_to(:manage, other_event_schedule) }
+      it { should be_able_to(:manage, my_conference.venue) }
+      it { should_not be_able_to(:manage, conference_public.venue) }
+      it { should be_able_to(:manage, my_conference.lodgings.first) }
+      it { should_not be_able_to(:manage, conference_public.lodgings.first) }
+      it { should be_able_to(:manage, my_conference.sponsors.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsors.first) }
+      it { should be_able_to(:manage, my_conference.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
+      it { should be_able_to(:manage, my_conference.tickets.first) }
+      it { should_not be_able_to(:manage, conference_public.tickets.first) }
 
-      it{ should be_able_to(:manage, my_registration) }
-      it{ should_not be_able_to(:manage, other_registration) }
+      it { should be_able_to(:manage, my_registration) }
+      it { should_not be_able_to(:manage, other_registration) }
 
-      it{ should be_able_to(:manage, my_event) }
-      it{ should_not be_able_to(:manage, other_event) }
-      it{ should be_able_to(:manage, my_event.event_type) }
-      it{ should_not be_able_to(:manage, other_event.event_type) }
-      it{ should be_able_to(:manage, my_event.track) }
-      it{ should_not be_able_to(:manage, other_event.track) }
-      it{ should be_able_to(:manage, my_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, other_event.difficulty_level) }
-      it{ should be_able_to(:manage, my_event.commercials.first) }
-      it{ should_not be_able_to(:manage, other_event.commercials.first) }
-      it{ should be_able_to(:index, my_event.comment_threads.first) }
-      it{ should_not be_able_to(:index, other_event.comment_threads.first) }
+      it { should be_able_to(:manage, my_event) }
+      it { should_not be_able_to(:manage, other_event) }
+      it { should be_able_to(:manage, my_event.event_type) }
+      it { should_not be_able_to(:manage, other_event.event_type) }
+      it { should be_able_to(:manage, my_event.track) }
+      it { should_not be_able_to(:manage, other_event.track) }
+      it { should be_able_to(:manage, my_event.difficulty_level) }
+      it { should_not be_able_to(:manage, other_event.difficulty_level) }
+      it { should be_able_to(:manage, my_event.commercials.first) }
+      it { should_not be_able_to(:manage, other_event.commercials.first) }
+      it { should be_able_to(:index, my_event.comment_threads.first) }
+      it { should_not be_able_to(:index, other_event.comment_threads.first) }
 
-      it{ should be_able_to(:manage, resource) }
+      it { should be_able_to(:manage, resource) }
 
-      it{ should_not be_able_to(:assign_org_admins, organization) }
-      it{ should_not be_able_to(:unassign_org_admins, organization) }
+      it { should_not be_able_to(:assign_org_admins, organization) }
+      it { should_not be_able_to(:unassign_org_admins, organization) }
 
       %w[organizer cfp info_desk volunteers_coordinator].each do |role|
-        it{ should be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:edit, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:update, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:show, Role.find_by(name: role, resource: my_conference)) }
-        it{ should be_able_to(:index, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:toggle_user, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:edit, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:update, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:show, Role.find_by(name: role, resource: my_conference)) }
+        it { should be_able_to(:index, Role.find_by(name: role, resource: my_conference)) }
       end
 
       context 'can manage track organizers' do
@@ -234,11 +236,11 @@ describe 'User with admin role' do
           @track_organizer_role = Role.where(name: 'track_organizer', resource: my_self_organized_track).first_or_create
         end
 
-        it{ should be_able_to(:toggle_user, @track_organizer_role) }
-        it{ should be_able_to(:edit, @track_organizer_role) }
-        it{ should be_able_to(:update, @track_organizer_role) }
-        it{ should be_able_to(:show, @track_organizer_role) }
-        it{ should be_able_to(:index, @track_organizer_role) }
+        it { should be_able_to(:toggle_user, @track_organizer_role) }
+        it { should be_able_to(:edit, @track_organizer_role) }
+        it { should be_able_to(:update, @track_organizer_role) }
+        it { should be_able_to(:show, @track_organizer_role) }
+        it { should be_able_to(:index, @track_organizer_role) }
       end
 
       it_behaves_like 'user with any role'
@@ -248,66 +250,66 @@ describe 'User with admin role' do
       let(:role) { Role.find_by(name: 'cfp', resource: my_conference) }
       let(:user) { create(:user, role_ids: [role.id]) }
 
-      it{ should_not be_able_to(:new, Conference.new) }
-      it{ should_not be_able_to(:create, Conference.new) }
-      it{ should_not be_able_to(:manage, my_conference) }
-      it{ should_not be_able_to(:manage, conference_public) }
-      it{ should_not be_able_to(:manage, my_conference.splashpage) }
-      it{ should_not be_able_to(:manage, conference_public.splashpage) }
-      it{ should_not be_able_to(:manage, my_conference.contact) }
-      it{ should_not be_able_to(:manage, conference_public.contact) }
-      it{ should be_able_to(:manage, my_conference.email_settings) }
-      it{ should_not be_able_to(:manage, conference_public.email_settings) }
-      it{ should_not be_able_to(:manage, my_conference.campaigns.first) }
-      it{ should_not be_able_to(:manage, conference_public.campaigns.first) }
-      it{ should_not be_able_to(:manage, my_conference.targets.first) }
-      it{ should_not be_able_to(:manage, conference_public.targets.first) }
-      it{ should_not be_able_to(:manage, my_conference.commercials.first) }
-      it{ should_not be_able_to(:manage, conference_public.commercials.first) }
-      it{ should_not be_able_to(:manage, my_conference.registration_period) }
-      it{ should_not be_able_to(:manage, conference_public.registration_period) }
-      it{ should_not be_able_to(:manage, my_conference.questions.first) }
-      it{ should_not be_able_to(:manage, conference_public.questions.first) }
-      it{ should be_able_to(:manage, my_conference.program.cfp) }
-      it{ should_not be_able_to(:manage, conference_public.program.cfp) }
-      it{ should be_able_to(:manage, my_schedule) }
-      it{ should_not be_able_to(:manage, other_schedule) }
-      it{ should_not be_able_to(:manage, my_event_schedule) }
-      it{ should_not be_able_to(:manage, other_event_schedule) }
-      it{ should_not be_able_to(:manage, my_conference.venue) }
-      it{ should be_able_to(:show, my_conference.venue) }
-      it{ should_not be_able_to(:manage, conference_public.venue) }
-      it{ should_not be_able_to(:manage, my_conference.lodgings.first) }
-      it{ should_not be_able_to(:manage, conference_public.lodgings.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsors.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsors.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, my_conference.tickets.first) }
-      it{ should_not be_able_to(:manage, conference_public.tickets.first) }
+      it { should_not be_able_to(:new, Conference.new) }
+      it { should_not be_able_to(:create, Conference.new) }
+      it { should_not be_able_to(:manage, my_conference) }
+      it { should_not be_able_to(:manage, conference_public) }
+      it { should_not be_able_to(:manage, my_conference.splashpage) }
+      it { should_not be_able_to(:manage, conference_public.splashpage) }
+      it { should_not be_able_to(:manage, my_conference.contact) }
+      it { should_not be_able_to(:manage, conference_public.contact) }
+      it { should be_able_to(:manage, my_conference.email_settings) }
+      it { should_not be_able_to(:manage, conference_public.email_settings) }
+      it { should_not be_able_to(:manage, my_conference.campaigns.first) }
+      it { should_not be_able_to(:manage, conference_public.campaigns.first) }
+      it { should_not be_able_to(:manage, my_conference.targets.first) }
+      it { should_not be_able_to(:manage, conference_public.targets.first) }
+      it { should_not be_able_to(:manage, my_conference.commercials.first) }
+      it { should_not be_able_to(:manage, conference_public.commercials.first) }
+      it { should_not be_able_to(:manage, my_conference.registration_period) }
+      it { should_not be_able_to(:manage, conference_public.registration_period) }
+      it { should_not be_able_to(:manage, my_conference.questions.first) }
+      it { should_not be_able_to(:manage, conference_public.questions.first) }
+      it { should be_able_to(:manage, my_conference.program.cfp) }
+      it { should_not be_able_to(:manage, conference_public.program.cfp) }
+      it { should be_able_to(:manage, my_schedule) }
+      it { should_not be_able_to(:manage, other_schedule) }
+      it { should_not be_able_to(:manage, my_event_schedule) }
+      it { should_not be_able_to(:manage, other_event_schedule) }
+      it { should_not be_able_to(:manage, my_conference.venue) }
+      it { should be_able_to(:show, my_conference.venue) }
+      it { should_not be_able_to(:manage, conference_public.venue) }
+      it { should_not be_able_to(:manage, my_conference.lodgings.first) }
+      it { should_not be_able_to(:manage, conference_public.lodgings.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsors.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsors.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, my_conference.tickets.first) }
+      it { should_not be_able_to(:manage, conference_public.tickets.first) }
 
-      it{ should_not be_able_to(:manage, my_registration) }
-      it{ should_not be_able_to(:manage, other_registration) }
+      it { should_not be_able_to(:manage, my_registration) }
+      it { should_not be_able_to(:manage, other_registration) }
 
-      it{ should be_able_to(:manage, my_event) }
-      it{ should_not be_able_to(:manage, other_event) }
-      it{ should be_able_to(:manage, my_event.event_type) }
-      it{ should_not be_able_to(:manage, other_event.event_type) }
-      it{ should be_able_to(:manage, my_event.track) }
-      it{ should_not be_able_to(:manage, other_event.track) }
-      it{ should be_able_to(:manage, my_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, other_event.difficulty_level) }
-      it{ should be_able_to(:manage, my_event.commercials.first) }
-      it{ should_not be_able_to(:manage, other_event.commercials.first) }
-      it{ should be_able_to(:index, my_event.comment_threads.first) }
-      it{ should_not be_able_to(:index, other_event.comment_threads.first) }
+      it { should be_able_to(:manage, my_event) }
+      it { should_not be_able_to(:manage, other_event) }
+      it { should be_able_to(:manage, my_event.event_type) }
+      it { should_not be_able_to(:manage, other_event.event_type) }
+      it { should be_able_to(:manage, my_event.track) }
+      it { should_not be_able_to(:manage, other_event.track) }
+      it { should be_able_to(:manage, my_event.difficulty_level) }
+      it { should_not be_able_to(:manage, other_event.difficulty_level) }
+      it { should be_able_to(:manage, my_event.commercials.first) }
+      it { should_not be_able_to(:manage, other_event.commercials.first) }
+      it { should be_able_to(:index, my_event.comment_threads.first) }
+      it { should_not be_able_to(:index, other_event.comment_threads.first) }
 
-      it{ should_not be_able_to(:manage, resource) }
-      it{ should be_able_to(:index, resource) }
-      it{ should be_able_to(:show, resource) }
-      it{ should be_able_to(:update, resource) }
-      it{ should_not be_able_to(:assign_org_admins, organization) }
-      it{ should_not be_able_to(:unassign_org_admins, organization) }
+      it { should_not be_able_to(:manage, resource) }
+      it { should be_able_to(:index, resource) }
+      it { should be_able_to(:show, resource) }
+      it { should be_able_to(:update, resource) }
+      it { should_not be_able_to(:assign_org_admins, organization) }
+      it { should_not be_able_to(:unassign_org_admins, organization) }
 
       it_behaves_like 'user with any role'
       it_behaves_like 'user with non-organizer role', 'cfp'
@@ -317,66 +319,66 @@ describe 'User with admin role' do
       let(:role) { Role.find_by(name: 'info_desk', resource: my_conference) }
       let(:user) { create(:user, role_ids: [role.id]) }
 
-      it{ should_not be_able_to(:new, Conference.new) }
-      it{ should_not be_able_to(:create, Conference.new) }
-      it{ should_not be_able_to(:manage, my_conference) }
-      it{ should_not be_able_to(:manage, conference_public) }
-      it{ should_not be_able_to(:manage, my_conference.splashpage) }
-      it{ should_not be_able_to(:manage, conference_public.splashpage) }
-      it{ should_not be_able_to(:manage, my_conference.contact) }
-      it{ should_not be_able_to(:manage, conference_public.contact) }
-      it{ should_not be_able_to(:manage, my_conference.email_settings) }
-      it{ should_not be_able_to(:manage, conference_public.email_settings) }
-      it{ should_not be_able_to(:manage, my_conference.campaigns.first) }
-      it{ should_not be_able_to(:manage, conference_public.campaigns.first) }
-      it{ should_not be_able_to(:manage, my_conference.targets.first) }
-      it{ should_not be_able_to(:manage, conference_public.targets.first) }
-      it{ should_not be_able_to(:manage, my_conference.commercials.first) }
-      it{ should_not be_able_to(:manage, conference_public.commercials.first) }
-      it{ should_not be_able_to(:manage, my_conference.registration_period) }
-      it{ should_not be_able_to(:manage, conference_public.registration_period) }
-      it{ should be_able_to(:manage, my_conference.questions.first) }
-      it{ should_not be_able_to(:manage, conference_public.questions.first) }
-      it{ should_not be_able_to(:manage, my_conference.program.cfp) }
-      it{ should_not be_able_to(:manage, conference_public.program.cfp) }
-      it{ should_not be_able_to(:manage, my_schedule) }
-      it{ should_not be_able_to(:manage, other_schedule) }
-      it{ should_not be_able_to(:manage, my_event_schedule) }
-      it{ should_not be_able_to(:manage, other_event_schedule) }
-      it{ should_not be_able_to(:manage, my_conference.venue) }
-      it{ should_not be_able_to(:show, my_conference.venue) }
-      it{ should_not be_able_to(:manage, conference_public.venue) }
-      it{ should_not be_able_to(:manage, my_conference.lodgings.first) }
-      it{ should_not be_able_to(:manage, conference_public.lodgings.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsors.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsors.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, my_conference.tickets.first) }
-      it{ should_not be_able_to(:manage, conference_public.tickets.first) }
+      it { should_not be_able_to(:new, Conference.new) }
+      it { should_not be_able_to(:create, Conference.new) }
+      it { should_not be_able_to(:manage, my_conference) }
+      it { should_not be_able_to(:manage, conference_public) }
+      it { should_not be_able_to(:manage, my_conference.splashpage) }
+      it { should_not be_able_to(:manage, conference_public.splashpage) }
+      it { should_not be_able_to(:manage, my_conference.contact) }
+      it { should_not be_able_to(:manage, conference_public.contact) }
+      it { should_not be_able_to(:manage, my_conference.email_settings) }
+      it { should_not be_able_to(:manage, conference_public.email_settings) }
+      it { should_not be_able_to(:manage, my_conference.campaigns.first) }
+      it { should_not be_able_to(:manage, conference_public.campaigns.first) }
+      it { should_not be_able_to(:manage, my_conference.targets.first) }
+      it { should_not be_able_to(:manage, conference_public.targets.first) }
+      it { should_not be_able_to(:manage, my_conference.commercials.first) }
+      it { should_not be_able_to(:manage, conference_public.commercials.first) }
+      it { should_not be_able_to(:manage, my_conference.registration_period) }
+      it { should_not be_able_to(:manage, conference_public.registration_period) }
+      it { should be_able_to(:manage, my_conference.questions.first) }
+      it { should_not be_able_to(:manage, conference_public.questions.first) }
+      it { should_not be_able_to(:manage, my_conference.program.cfp) }
+      it { should_not be_able_to(:manage, conference_public.program.cfp) }
+      it { should_not be_able_to(:manage, my_schedule) }
+      it { should_not be_able_to(:manage, other_schedule) }
+      it { should_not be_able_to(:manage, my_event_schedule) }
+      it { should_not be_able_to(:manage, other_event_schedule) }
+      it { should_not be_able_to(:manage, my_conference.venue) }
+      it { should_not be_able_to(:show, my_conference.venue) }
+      it { should_not be_able_to(:manage, conference_public.venue) }
+      it { should_not be_able_to(:manage, my_conference.lodgings.first) }
+      it { should_not be_able_to(:manage, conference_public.lodgings.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsors.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsors.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, my_conference.tickets.first) }
+      it { should_not be_able_to(:manage, conference_public.tickets.first) }
 
-      it{ should be_able_to(:manage, my_registration) }
-      it{ should_not be_able_to(:manage, other_registration) }
+      it { should be_able_to(:manage, my_registration) }
+      it { should_not be_able_to(:manage, other_registration) }
 
-      it{ should_not be_able_to(:manage, my_event) }
-      it{ should_not be_able_to(:manage, other_event) }
-      it{ should_not be_able_to(:manage, my_event.event_type) }
-      it{ should_not be_able_to(:manage, other_event.event_type) }
-      it{ should_not be_able_to(:manage, my_event.track) }
-      it{ should_not be_able_to(:manage, other_event.track) }
-      it{ should_not be_able_to(:manage, my_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, other_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, my_event.commercials.first) }
-      it{ should_not be_able_to(:manage, other_event.commercials.first) }
-      it{ should_not be_able_to(:index, my_event.comment_threads.first) }
-      it{ should_not be_able_to(:index, other_event.comment_threads.first) }
+      it { should_not be_able_to(:manage, my_event) }
+      it { should_not be_able_to(:manage, other_event) }
+      it { should_not be_able_to(:manage, my_event.event_type) }
+      it { should_not be_able_to(:manage, other_event.event_type) }
+      it { should_not be_able_to(:manage, my_event.track) }
+      it { should_not be_able_to(:manage, other_event.track) }
+      it { should_not be_able_to(:manage, my_event.difficulty_level) }
+      it { should_not be_able_to(:manage, other_event.difficulty_level) }
+      it { should_not be_able_to(:manage, my_event.commercials.first) }
+      it { should_not be_able_to(:manage, other_event.commercials.first) }
+      it { should_not be_able_to(:index, my_event.comment_threads.first) }
+      it { should_not be_able_to(:index, other_event.comment_threads.first) }
 
-      it{ should_not be_able_to(:manage, resource) }
-      it{ should be_able_to(:index, resource) }
-      it{ should be_able_to(:show, resource) }
-      it{ should be_able_to(:update, resource) }
-      it{ should_not be_able_to(:assign_org_admins, organization) }
-      it{ should_not be_able_to(:unassign_org_admins, organization) }
+      it { should_not be_able_to(:manage, resource) }
+      it { should be_able_to(:index, resource) }
+      it { should be_able_to(:show, resource) }
+      it { should be_able_to(:update, resource) }
+      it { should_not be_able_to(:assign_org_admins, organization) }
+      it { should_not be_able_to(:unassign_org_admins, organization) }
 
       it_behaves_like 'user with any role'
       it_behaves_like 'user with non-organizer role', 'info_desk'
@@ -386,66 +388,66 @@ describe 'User with admin role' do
       let(:role) { Role.find_by(name: 'volunteers_coordinator', resource: my_conference) }
       let(:user) { create(:user, role_ids: [role.id]) }
 
-      it{ should_not be_able_to(:new, Conference.new) }
-      it{ should_not be_able_to(:create, Conference.new) }
-      it{ should_not be_able_to(:manage, my_conference) }
-      it{ should_not be_able_to(:manage, conference_public) }
-      it{ should_not be_able_to(:manage, my_conference.splashpage) }
-      it{ should_not be_able_to(:manage, conference_public.splashpage) }
-      it{ should_not be_able_to(:manage, my_conference.contact) }
-      it{ should_not be_able_to(:manage, conference_public.contact) }
-      it{ should_not be_able_to(:manage, my_conference.email_settings) }
-      it{ should_not be_able_to(:manage, conference_public.email_settings) }
-      it{ should_not be_able_to(:manage, my_conference.campaigns.first) }
-      it{ should_not be_able_to(:manage, conference_public.campaigns.first) }
-      it{ should_not be_able_to(:manage, my_conference.targets.first) }
-      it{ should_not be_able_to(:manage, conference_public.targets.first) }
-      it{ should_not be_able_to(:manage, my_conference.commercials.first) }
-      it{ should_not be_able_to(:manage, conference_public.commercials.first) }
-      it{ should_not be_able_to(:manage, my_conference.registration_period) }
-      it{ should_not be_able_to(:manage, conference_public.registration_period) }
-      it{ should_not be_able_to(:manage, my_conference.questions.first) }
-      it{ should_not be_able_to(:manage, conference_public.questions.first) }
-      it{ should_not be_able_to(:manage, my_conference.program.cfp) }
-      it{ should_not be_able_to(:manage, conference_public.program.cfp) }
-      it{ should_not be_able_to(:manage, my_schedule) }
-      it{ should_not be_able_to(:manage, other_schedule) }
-      it{ should_not be_able_to(:manage, my_event_schedule) }
-      it{ should_not be_able_to(:manage, other_event_schedule) }
-      it{ should_not be_able_to(:manage, my_conference.venue) }
-      it{ should_not be_able_to(:show, my_conference.venue) }
-      it{ should_not be_able_to(:manage, conference_public.venue) }
-      it{ should_not be_able_to(:manage, my_conference.lodgings.first) }
-      it{ should_not be_able_to(:manage, conference_public.lodgings.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsors.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsors.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, my_conference.tickets.first) }
-      it{ should_not be_able_to(:manage, conference_public.tickets.first) }
+      it { should_not be_able_to(:new, Conference.new) }
+      it { should_not be_able_to(:create, Conference.new) }
+      it { should_not be_able_to(:manage, my_conference) }
+      it { should_not be_able_to(:manage, conference_public) }
+      it { should_not be_able_to(:manage, my_conference.splashpage) }
+      it { should_not be_able_to(:manage, conference_public.splashpage) }
+      it { should_not be_able_to(:manage, my_conference.contact) }
+      it { should_not be_able_to(:manage, conference_public.contact) }
+      it { should_not be_able_to(:manage, my_conference.email_settings) }
+      it { should_not be_able_to(:manage, conference_public.email_settings) }
+      it { should_not be_able_to(:manage, my_conference.campaigns.first) }
+      it { should_not be_able_to(:manage, conference_public.campaigns.first) }
+      it { should_not be_able_to(:manage, my_conference.targets.first) }
+      it { should_not be_able_to(:manage, conference_public.targets.first) }
+      it { should_not be_able_to(:manage, my_conference.commercials.first) }
+      it { should_not be_able_to(:manage, conference_public.commercials.first) }
+      it { should_not be_able_to(:manage, my_conference.registration_period) }
+      it { should_not be_able_to(:manage, conference_public.registration_period) }
+      it { should_not be_able_to(:manage, my_conference.questions.first) }
+      it { should_not be_able_to(:manage, conference_public.questions.first) }
+      it { should_not be_able_to(:manage, my_conference.program.cfp) }
+      it { should_not be_able_to(:manage, conference_public.program.cfp) }
+      it { should_not be_able_to(:manage, my_schedule) }
+      it { should_not be_able_to(:manage, other_schedule) }
+      it { should_not be_able_to(:manage, my_event_schedule) }
+      it { should_not be_able_to(:manage, other_event_schedule) }
+      it { should_not be_able_to(:manage, my_conference.venue) }
+      it { should_not be_able_to(:show, my_conference.venue) }
+      it { should_not be_able_to(:manage, conference_public.venue) }
+      it { should_not be_able_to(:manage, my_conference.lodgings.first) }
+      it { should_not be_able_to(:manage, conference_public.lodgings.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsors.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsors.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, my_conference.tickets.first) }
+      it { should_not be_able_to(:manage, conference_public.tickets.first) }
 
-      it{ should_not be_able_to(:manage, registration) }
-      it{ should_not be_able_to(:manage, other_registration) }
+      it { should_not be_able_to(:manage, registration) }
+      it { should_not be_able_to(:manage, other_registration) }
 
-      it{ should_not be_able_to(:manage, my_event) }
-      it{ should_not be_able_to(:manage, other_event) }
-      it{ should_not be_able_to(:manage, my_event.event_type) }
-      it{ should_not be_able_to(:manage, other_event.event_type) }
-      it{ should_not be_able_to(:manage, my_event.track) }
-      it{ should_not be_able_to(:manage, other_event.track) }
-      it{ should_not be_able_to(:manage, my_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, other_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, my_event.commercials.first) }
-      it{ should_not be_able_to(:manage, other_event.commercials.first) }
-      it{ should_not be_able_to(:index, my_event.comment_threads.first) }
-      it{ should_not be_able_to(:index, other_event.comment_threads.first) }
+      it { should_not be_able_to(:manage, my_event) }
+      it { should_not be_able_to(:manage, other_event) }
+      it { should_not be_able_to(:manage, my_event.event_type) }
+      it { should_not be_able_to(:manage, other_event.event_type) }
+      it { should_not be_able_to(:manage, my_event.track) }
+      it { should_not be_able_to(:manage, other_event.track) }
+      it { should_not be_able_to(:manage, my_event.difficulty_level) }
+      it { should_not be_able_to(:manage, other_event.difficulty_level) }
+      it { should_not be_able_to(:manage, my_event.commercials.first) }
+      it { should_not be_able_to(:manage, other_event.commercials.first) }
+      it { should_not be_able_to(:index, my_event.comment_threads.first) }
+      it { should_not be_able_to(:index, other_event.comment_threads.first) }
 
-      it{ should_not be_able_to(:manage, resource) }
-      it{ should be_able_to(:index, resource) }
-      it{ should be_able_to(:show, resource) }
-      it{ should be_able_to(:update, resource) }
-      it{ should_not be_able_to(:assign_org_admins, organization) }
-      it{ should_not be_able_to(:unassign_org_admins, organization) }
+      it { should_not be_able_to(:manage, resource) }
+      it { should be_able_to(:index, resource) }
+      it { should be_able_to(:show, resource) }
+      it { should be_able_to(:update, resource) }
+      it { should_not be_able_to(:assign_org_admins, organization) }
+      it { should_not be_able_to(:unassign_org_admins, organization) }
 
       it 'should be_able to :manage Vposition'
       it 'should be_able to :manage Vday'
@@ -455,7 +457,6 @@ describe 'User with admin role' do
     end
 
     context 'when user has the role track_organizer' do
-
       let(:role) { Role.where(name: 'track_organizer', resource: my_self_organized_track).first_or_create }
       let(:user) { create(:user, role_ids: [role.id]) }
       let(:new_track) { build(:track, program: my_conference.program) }
@@ -467,79 +468,79 @@ describe 'User with admin role' do
       let(:my_self_organized_track_schedule) { create(:schedule, program: my_conference.program, track: my_self_organized_track) }
       let(:my_self_organized_track_event_schedule) { create(:event_schedule, event: my_self_organized_track_event, schedule: my_self_organized_track_schedule, room: my_self_organized_track.room) }
 
-      it{ should_not be_able_to(:new, Conference.new) }
-      it{ should_not be_able_to(:create, Conference.new) }
-      it{ should_not be_able_to(:manage, my_conference) }
-      it{ should_not be_able_to(:manage, conference_public) }
-      it{ should_not be_able_to(:manage, my_conference.splashpage) }
-      it{ should_not be_able_to(:manage, conference_public.splashpage) }
-      it{ should_not be_able_to(:manage, my_conference.contact) }
-      it{ should_not be_able_to(:manage, conference_public.contact) }
-      it{ should_not be_able_to(:manage, my_conference.email_settings) }
-      it{ should_not be_able_to(:manage, conference_public.email_settings) }
-      it{ should_not be_able_to(:manage, my_conference.campaigns.first) }
-      it{ should_not be_able_to(:manage, conference_public.campaigns.first) }
-      it{ should_not be_able_to(:manage, my_conference.targets.first) }
-      it{ should_not be_able_to(:manage, conference_public.targets.first) }
-      it{ should_not be_able_to(:manage, my_conference.commercials.first) }
-      it{ should_not be_able_to(:manage, conference_public.commercials.first) }
-      it{ should_not be_able_to(:manage, my_conference.registration_period) }
-      it{ should_not be_able_to(:manage, conference_public.registration_period) }
-      it{ should_not be_able_to(:manage, my_conference.questions.first) }
-      it{ should_not be_able_to(:manage, conference_public.questions.first) }
-      it{ should_not be_able_to(:manage, my_conference.program.cfp) }
-      it{ should_not be_able_to(:manage, conference_public.program.cfp) }
-      it{ should_not be_able_to(:manage, my_schedule) }
-      it{ should_not be_able_to(:manage, other_schedule) }
-      it{ should_not be_able_to(:manage, my_event_schedule) }
-      it{ should_not be_able_to(:manage, other_event_schedule) }
-      it{ should_not be_able_to(:manage, my_conference.venue) }
-      it{ should_not be_able_to(:show, my_conference.venue) }
-      it{ should_not be_able_to(:manage, conference_public.venue) }
-      it{ should_not be_able_to(:manage, my_conference.lodgings.first) }
-      it{ should_not be_able_to(:manage, conference_public.lodgings.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsors.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsors.first) }
-      it{ should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
-      it{ should_not be_able_to(:manage, my_conference.tickets.first) }
-      it{ should_not be_able_to(:manage, conference_public.tickets.first) }
+      it { should_not be_able_to(:new, Conference.new) }
+      it { should_not be_able_to(:create, Conference.new) }
+      it { should_not be_able_to(:manage, my_conference) }
+      it { should_not be_able_to(:manage, conference_public) }
+      it { should_not be_able_to(:manage, my_conference.splashpage) }
+      it { should_not be_able_to(:manage, conference_public.splashpage) }
+      it { should_not be_able_to(:manage, my_conference.contact) }
+      it { should_not be_able_to(:manage, conference_public.contact) }
+      it { should_not be_able_to(:manage, my_conference.email_settings) }
+      it { should_not be_able_to(:manage, conference_public.email_settings) }
+      it { should_not be_able_to(:manage, my_conference.campaigns.first) }
+      it { should_not be_able_to(:manage, conference_public.campaigns.first) }
+      it { should_not be_able_to(:manage, my_conference.targets.first) }
+      it { should_not be_able_to(:manage, conference_public.targets.first) }
+      it { should_not be_able_to(:manage, my_conference.commercials.first) }
+      it { should_not be_able_to(:manage, conference_public.commercials.first) }
+      it { should_not be_able_to(:manage, my_conference.registration_period) }
+      it { should_not be_able_to(:manage, conference_public.registration_period) }
+      it { should_not be_able_to(:manage, my_conference.questions.first) }
+      it { should_not be_able_to(:manage, conference_public.questions.first) }
+      it { should_not be_able_to(:manage, my_conference.program.cfp) }
+      it { should_not be_able_to(:manage, conference_public.program.cfp) }
+      it { should_not be_able_to(:manage, my_schedule) }
+      it { should_not be_able_to(:manage, other_schedule) }
+      it { should_not be_able_to(:manage, my_event_schedule) }
+      it { should_not be_able_to(:manage, other_event_schedule) }
+      it { should_not be_able_to(:manage, my_conference.venue) }
+      it { should_not be_able_to(:show, my_conference.venue) }
+      it { should_not be_able_to(:manage, conference_public.venue) }
+      it { should_not be_able_to(:manage, my_conference.lodgings.first) }
+      it { should_not be_able_to(:manage, conference_public.lodgings.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsors.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsors.first) }
+      it { should_not be_able_to(:manage, my_conference.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, conference_public.sponsorship_levels.first) }
+      it { should_not be_able_to(:manage, my_conference.tickets.first) }
+      it { should_not be_able_to(:manage, conference_public.tickets.first) }
 
-      it{ should_not be_able_to(:manage, registration) }
-      it{ should_not be_able_to(:manage, other_registration) }
+      it { should_not be_able_to(:manage, registration) }
+      it { should_not be_able_to(:manage, other_registration) }
 
-      it{ should_not be_able_to(:manage, my_event) }
-      it{ should_not be_able_to(:manage, other_event) }
-      it{ should_not be_able_to(:manage, my_event.event_type) }
-      it{ should_not be_able_to(:manage, other_event.event_type) }
-      it{ should_not be_able_to(:manage, my_event.track) }
-      it{ should_not be_able_to(:manage, other_event.track) }
-      it{ should_not be_able_to(:manage, my_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, other_event.difficulty_level) }
-      it{ should_not be_able_to(:manage, my_event.commercials.first) }
-      it{ should_not be_able_to(:manage, other_event.commercials.first) }
-      it{ should_not be_able_to(:index, my_event.comment_threads.first) }
-      it{ should_not be_able_to(:index, other_event.comment_threads.first) }
+      it { should_not be_able_to(:manage, my_event) }
+      it { should_not be_able_to(:manage, other_event) }
+      it { should_not be_able_to(:manage, my_event.event_type) }
+      it { should_not be_able_to(:manage, other_event.event_type) }
+      it { should_not be_able_to(:manage, my_event.track) }
+      it { should_not be_able_to(:manage, other_event.track) }
+      it { should_not be_able_to(:manage, my_event.difficulty_level) }
+      it { should_not be_able_to(:manage, other_event.difficulty_level) }
+      it { should_not be_able_to(:manage, my_event.commercials.first) }
+      it { should_not be_able_to(:manage, other_event.commercials.first) }
+      it { should_not be_able_to(:index, my_event.comment_threads.first) }
+      it { should_not be_able_to(:index, other_event.comment_threads.first) }
 
-      it{ should_not be_able_to(:manage, resource) }
+      it { should_not be_able_to(:manage, resource) }
 
-      it{ should be_able_to(:show, my_conference.program) }
-      it{ should be_able_to(:update, new_track) }
-      it{ should be_able_to(:manage, my_self_organized_track) }
-      it{ should_not be_able_to(:edit, my_self_organized_track) }
-      it{ should_not be_able_to(:update, my_self_organized_track) }
+      it { should be_able_to(:show, my_conference.program) }
+      it { should be_able_to(:update, new_track) }
+      it { should be_able_to(:manage, my_self_organized_track) }
+      it { should_not be_able_to(:edit, my_self_organized_track) }
+      it { should_not be_able_to(:update, my_self_organized_track) }
 
-      it{ should_not be_able_to(:assign_org_admins, organization) }
-      it{ should_not be_able_to(:unassign_org_admins, organization) }
+      it { should_not be_able_to(:assign_org_admins, organization) }
+      it { should_not be_able_to(:unassign_org_admins, organization) }
 
-      it{ should be_able_to(:update, new_event) }
-      it{ should be_able_to(:manage, my_self_organized_track_event) }
-      it{ should be_able_to(:manage, my_self_organized_track_event_commercial) }
+      it { should be_able_to(:update, new_event) }
+      it { should be_able_to(:manage, my_self_organized_track_event) }
+      it { should be_able_to(:manage, my_self_organized_track_event_commercial) }
 
-      it{ should be_able_to(:update, new_schedule) }
-      it{ should be_able_to(:new, new_track_schedule) }
-      it{ should be_able_to(:manage, my_self_organized_track_schedule) }
-      it{ should be_able_to(:manage, my_self_organized_track_event_schedule) }
+      it { should be_able_to(:update, new_schedule) }
+      it { should be_able_to(:new, new_track_schedule) }
+      it { should be_able_to(:manage, my_self_organized_track_schedule) }
+      it { should be_able_to(:manage, my_self_organized_track_event_schedule) }
 
       it_behaves_like 'user with any role'
       it_behaves_like 'user with non-organizer role', 'track_organizer'
diff --git a/spec/models/booth_spec.rb b/spec/models/booth_spec.rb
index 287653ac..a297b347 100644
--- a/spec/models/booth_spec.rb
+++ b/spec/models/booth_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'Booth' do
@@ -33,8 +35,8 @@ describe 'Booth' do
       end
     end
 
-    states = [:new, :withdrawn, :to_accept, :accepted, :to_reject, :rejected, :canceled, :confirmed]
-    transitions = [:restart, :withdraw, :accept, :reject, :to_accept, :to_reject, :cancel]
+    states = %i[new withdrawn to_accept accepted to_reject rejected canceled confirmed]
+    transitions = %i[restart withdraw accept reject to_accept to_reject cancel]
 
     states_transitions = { new: { restart: false, withdraw: true, accept: true, to_accept: true, to_reject: true, reject: true, cancel: false, confirm: false },
                            withdrawn: { restart: true, withdraw: false, accept: false, to_accept: false, to_reject: false, reject: false, cancel: false, confirm: false },
@@ -51,5 +53,4 @@ describe 'Booth' do
       end
     end
   end
-
 end
diff --git a/spec/models/campaign_spec.rb b/spec/models/campaign_spec.rb
index 4127371a..178717ae 100644
--- a/spec/models/campaign_spec.rb
+++ b/spec/models/campaign_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 require 'ahoy'
 
diff --git a/spec/models/cfp_spec.rb b/spec/models/cfp_spec.rb
index 6c437d35..f836c560 100644
--- a/spec/models/cfp_spec.rb
+++ b/spec/models/cfp_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Cfp do
diff --git a/spec/models/comment_spec.rb b/spec/models/comment_spec.rb
index 94cb6372..782bd8d7 100644
--- a/spec/models/comment_spec.rb
+++ b/spec/models/comment_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Commercial do
-
   describe '.find_since_last_login' do
     it 'returns none if last_sign_in_at is nil' do
       expect(Comment.find_since_last_login(create(:user))).to eq(Comment.none)
diff --git a/spec/models/commercial_spec.rb b/spec/models/commercial_spec.rb
index fbfac855..f9fefac9 100644
--- a/spec/models/commercial_spec.rb
+++ b/spec/models/commercial_spec.rb
@@ -1,7 +1,7 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Commercial do
-
   it { should validate_presence_of(:url) }
-
 end
diff --git a/spec/models/conference_spec.rb b/spec/models/conference_spec.rb
index 0af13eed..375f8af6 100755
--- a/spec/models/conference_spec.rb
+++ b/spec/models/conference_spec.rb
@@ -1,19 +1,18 @@
 #!/bin/env ruby
-# encoding: utf-8
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Conference do
-
-  let(:subject) { create(:conference, start_date: Date.new(2014, 06, 30), end_date: Date.new(2014, 06, 30)) }
+  let(:subject) { create(:conference, start_date: Date.new(2014, 0o6, 30), end_date: Date.new(2014, 0o6, 30)) }
 
   describe '#write_event_distribution_to_db' do
-
     it 'updates pending conferences' do
       create(:conference,
              start_date: Date.today - 2.weeks,
-             end_date: Date.today - 1.weeks)
+             end_date: Date.today - 1.week)
 
-      subject.start_date = Date.today + 1.weeks
+      subject.start_date = Date.today + 1.week
       subject.end_date = Date.today + 2.weeks
 
       result = {
@@ -25,7 +24,7 @@ describe Conference do
             withdrawn: 0,
             canceled: 0,
             rejected: 0
-          },
+          }
       }
 
       Conference.write_event_distribution_to_db
@@ -36,7 +35,7 @@ describe Conference do
     it 'does not update past conferences' do
       old_conference = create(:conference,
                               start_date: Date.today - 2.weeks,
-                              end_date: Date.today - 1.weeks)
+                              end_date: Date.today - 1.week)
 
       Conference.write_event_distribution_to_db
       old_conference.reload
@@ -82,7 +81,7 @@ describe Conference do
             withdrawn: 1,
             canceled: 1,
             rejected: 1
-          },
+          }
       }
 
       subject.reload
@@ -103,7 +102,7 @@ describe Conference do
             canceled: 0,
             rejected: 0
           },
-        DateTime.now.end_of_week - 1.weeks =>
+        DateTime.now.end_of_week - 1.week =>
           {
             confirmed: 3,
             unconfirmed: 4,
@@ -111,7 +110,7 @@ describe Conference do
             withdrawn: 0,
             canceled: 0,
             rejected: 0
-          },
+          }
       }
       subject.events_per_week = db_data
       subject.save
@@ -138,7 +137,7 @@ describe Conference do
             canceled: 0,
             rejected: 0
           },
-        DateTime.now.end_of_week - 1.weeks =>
+        DateTime.now.end_of_week - 1.week =>
           {
             confirmed: 3,
             unconfirmed: 4,
@@ -155,7 +154,7 @@ describe Conference do
             withdrawn: 0,
             canceled: 0,
             rejected: 0
-          },
+          }
       }
 
       subject.reload
@@ -176,11 +175,11 @@ describe Conference do
       db_data = {
         Date.today.end_of_week - 2.weeks => {
           confirmed: 1,
-          unconfirmed: 2,
+          unconfirmed: 2
         },
-        Date.today.end_of_week - 1.weeks => {
+        Date.today.end_of_week - 1.week => {
           confirmed: 3,
-          unconfirmed: 4,
+          unconfirmed: 4
         }
       }
       subject.events_per_week = db_data
@@ -248,11 +247,11 @@ describe Conference do
       db_data = {
         Date.today.end_of_week - 3.weeks => {
           confirmed: 1,
-          unconfirmed: 2,
+          unconfirmed: 2
         },
-        Date.today.end_of_week - 1.weeks => {
+        Date.today.end_of_week - 1.week => {
           confirmed: 3,
-          unconfirmed: 4,
+          unconfirmed: 4
         }
       }
       subject.events_per_week = db_data
@@ -298,7 +297,6 @@ describe Conference do
       expect(subject.get_top_submitter.values).to eq([3, 1])
       expect(subject.get_top_submitter.keys).to eq([e2.submitter, e1.submitter])
     end
-
   end
 
   describe '#get_targets' do
@@ -391,7 +389,6 @@ describe Conference do
 
     describe '#new_program_minutes' do
       it 'calculates correct values with events' do
-
         create(:event, program: subject.program, event_type: @long, created_at: Time.now - 3.days)
         create(:event, program: subject.program, event_type: @long)
         create(:event, program: subject.program, event_type: @short, created_at: Time.now - 3.days)
@@ -418,7 +415,6 @@ describe Conference do
     end
 
     describe '#difficulty_levels_distribution' do
-
       it 'calculates correct for different difficulty levels' do
         create(:event, program: subject.program, difficulty_level: @easy)
         create(:event, program: subject.program, difficulty_level: @easy)
@@ -426,11 +422,11 @@ describe Conference do
         result = {}
         result['Hard'] = {
           'value' => 1,
-          'color' => '#FFFFFF',
+          'color' => '#FFFFFF'
         }
         result['Easy'] = {
           'value' => 2,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.difficulty_levels_distribution).to eq(result)
       end
@@ -440,7 +436,7 @@ describe Conference do
         result = {}
         result['Easy'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.difficulty_levels_distribution).to eq(result)
       end
@@ -495,7 +491,7 @@ describe Conference do
         result = {}
         result['Easy'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.difficulty_levels_distribution(:confirmed)).to eq(result)
       end
@@ -522,11 +518,11 @@ describe Conference do
         result = {}
         result['Workshop'] = {
           'value' => 2,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         result['Lecture'] = {
           'value' => 1,
-          'color' => '#FFFFFF',
+          'color' => '#FFFFFF'
         }
         expect(subject.event_type_distribution).to eq(result)
       end
@@ -536,7 +532,7 @@ describe Conference do
         result = {}
         result['Workshop'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.event_type_distribution).to eq(result)
       end
@@ -591,7 +587,7 @@ describe Conference do
         result = {}
         result['Workshop'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.event_type_distribution(:confirmed)).to eq(result)
       end
@@ -618,11 +614,11 @@ describe Conference do
         result = {}
         result['Track One'] = {
           'value' => 2,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         result['Track Two'] = {
           'value' => 1,
-          'color' => '#FFFFFF',
+          'color' => '#FFFFFF'
         }
         expect(subject.tracks_distribution).to eq(result)
       end
@@ -632,7 +628,7 @@ describe Conference do
         result = {}
         result['Track One'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.tracks_distribution).to eq(result)
       end
@@ -687,7 +683,7 @@ describe Conference do
         result = {}
         result['Track One'] = {
           'value' => 1,
-          'color' => '#000000',
+          'color' => '#000000'
         }
         expect(subject.tracks_distribution(:confirmed)).to eq(result)
       end
@@ -700,7 +696,6 @@ describe Conference do
   end
 
   describe '#get_active_conferences' do
-
     it 'returns pending conferences' do
       a = create(:conference,
                  short_title: 'a', start_date: Time.now + 14.days,
@@ -738,13 +733,13 @@ describe Conference do
 
   describe '#get_deactive_conferences' do
     it 'returns all conferences without the active conferences' do
-      a = create(:conference,  start_date: Time.now - 3.year, end_date: Time.now - 1080.days)
-      b = create(:conference,  start_date: Time.now - 2.year, end_date: Time.now - 720.days)
+      a = create(:conference,  start_date: Time.now - 3.years, end_date: Time.now - 1080.days)
+      b = create(:conference,  start_date: Time.now - 2.years, end_date: Time.now - 720.days)
       c = create(:conference, start_date: Time.now - 1.year, end_date: Time.now - 360.days)
       result = [a, b, c]
 
       expect(Conference.get_conferences_without_active_for_dashboard([subject]))
-          .to match_array(result)
+        .to match_array(result)
     end
 
     it 'returns all conferences if there are no active conferences' do
@@ -762,7 +757,7 @@ describe Conference do
     end
 
     it 'return no conferences if there are only two conferences and no pending' do
-      a = create(:conference,  start_date: Time.now - 2.year, end_date: Time.now - 720.days)
+      a = create(:conference, start_date: Time.now - 2.years, end_date: Time.now - 720.days)
       b = create(:conference, start_date: Time.now - 1.year, end_date: Time.now - 360.days)
       expect(Conference.get_conferences_without_active_for_dashboard([a, b])).to match_array([])
     end
@@ -801,11 +796,11 @@ describe Conference do
   end
 
   describe '#event_distribution' do
-
     before(:each) do
       @conference = create(
-          :conference,
-          email_settings: create(:email_settings))
+        :conference,
+        email_settings: create(:email_settings)
+      )
       @conference.email_settings = create(:email_settings)
 
       @options = {}
@@ -969,7 +964,6 @@ describe Conference do
   end
 
   describe '#get_status' do
-
     before(:each) do
       # Setup positive result hash
       @result = {}
@@ -983,7 +977,7 @@ describe Conference do
       @result['splashpage'] = true
 
       # Setup negative result hash
-      @result_false = Hash.new
+      @result_false = {}
       @result.each { |key, value| @result_false[key] = !value }
 
       @result['short_title'] = @result_false['short_title'] = subject.short_title
@@ -1037,7 +1031,7 @@ describe Conference do
     end
 
     it 'calculates correct for conference with registration, cfp, venue' do
-      expect(subject.end_date).to eq Date.new(2014, 06, 30)
+      expect(subject.end_date).to eq Date.new(2014, 0o6, 30)
       subject.registration_period = create(:registration_period,
                                            start_date: subject.end_date - 14,
                                            end_date: subject.end_date, conference: subject)
@@ -1141,7 +1135,6 @@ describe Conference do
   end
 
   describe '#registration_weeks' do
-
     it 'calculates new year' do
       subject.registration_period = create(:registration_period,
                                            start_date: Date.new(2013, 12, 31),
@@ -1151,28 +1144,27 @@ describe Conference do
 
     it 'is one if start and end are 6 days apart' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 6, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 6, conference: subject)
       expect(subject.registration_weeks).to eq(1)
     end
 
     it 'is one if start and end date are the same' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26), conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26), conference: subject)
       expect(subject.registration_weeks).to eq(1)
     end
 
     it 'is two if start and end are 10 days apart' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 17),
-                                           end_date: Date.new(2014, 05, 15) + 10, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 17),
+                                           end_date: Date.new(2014, 0o5, 15) + 10, conference: subject)
       expect(subject.registration_weeks).to eq(2)
     end
   end
 
   describe '#cfp_weeks' do
-
     it 'calculates new year' do
       cfp = create(:cfp, program: subject.program)
       cfp.start_date = Date.new(2013, 12, 30)
@@ -1183,228 +1175,224 @@ describe Conference do
 
     it 'is one if start and end are 6 days apart' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 6
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 6
       cfp.save!
       expect(subject.cfp_weeks).to eq(1)
     end
 
     it 'is one if start and end are the same date' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26)
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26)
       cfp.save!
       expect(subject.cfp_weeks).to eq(1)
     end
 
     it 'is two if start and end are 10 days apart' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 10
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 10
       cfp.save!
       expect(subject.cfp_weeks).to eq(2)
     end
   end
 
   describe '#get_submissions_per_week' do
-
     it 'does calculate correct if cfp start date is altered' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) - 7)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) - 7)]
       expect(subject.get_submissions_per_week).to eq([1, 1, 1, 1, 1])
     end
 
     it 'does calculate correct if cfp end date is altered' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 28)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 28)]
       expect(subject.get_submissions_per_week).to eq([0, 0, 0, 0, 1])
     end
 
     it 'pads with zeros if there are no submissions' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
       expect(subject.get_submissions_per_week).to eq([0, 0, 0, 0])
     end
 
     it 'summarized correct if there are no submissions in one week' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 28
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 28
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 7)]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 14)]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 28)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 7)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 14)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 28)]
       expect(subject.get_submissions_per_week).to eq([0, 1, 2, 2, 3])
     end
 
     it 'summarized correct if there are submissions every week except the first' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 7)]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 14)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 7)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 14)]
       expect(subject.get_submissions_per_week).to eq([0, 1, 2, 2])
     end
 
     it 'summarized correct if there are submissions every week' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26))]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 7)]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 14)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26))]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 7)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 14)]
       expect(subject.get_submissions_per_week).to eq([1, 2, 3, 3])
     end
 
     it 'pads left' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 21)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 21)]
       expect(subject.get_submissions_per_week).to eq([0, 0, 0, 1])
     end
 
     it 'pads middle' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26))]
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26) + 21)]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26))]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26) + 21)]
       expect(subject.get_submissions_per_week).to eq([1, 1, 1, 2])
     end
 
     it 'pads right' do
       cfp = create(:cfp, program: subject.program)
-      cfp.start_date = Date.new(2014, 05, 26)
-      cfp.end_date = Date.new(2014, 05, 26) + 21
+      cfp.start_date = Date.new(2014, 0o5, 26)
+      cfp.end_date = Date.new(2014, 0o5, 26) + 21
       cfp.save!
-      subject.program.events += [create(:event, created_at: Date.new(2014, 05, 26))]
+      subject.program.events += [create(:event, created_at: Date.new(2014, 0o5, 26))]
       expect(subject.get_submissions_per_week).to eq([1, 1, 1, 1])
     end
   end
 
   describe '#get_registrations_per_week' do
-
     it 'pads with zeros if there are no registrations' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 21, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 21, conference: subject)
 
       expect(subject.get_registrations_per_week).to eq([0, 0, 0, 0])
     end
 
     it 'summarized correct if there are no registrations in one week' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 28, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 28, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 7)
+                            created_at: Date.new(2014, 0o5, 26) + 7)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 14)
+                            created_at: Date.new(2014, 0o5, 26) + 14)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 28)
+                            created_at: Date.new(2014, 0o5, 26) + 28)
 
       expect(subject.get_registrations_per_week).to eq([0, 1, 2, 2, 3])
     end
 
     it 'returns [1] if there is one registration on the first day' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 7, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 7, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26))
+                            created_at: Date.new(2014, 0o5, 26))
       expect(subject.get_registrations_per_week).to eq([1, 1])
     end
 
     it 'summarized correct if there are registrations every week' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 21, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 21, conference: subject)
 
-      create(:registration, conference: subject, created_at: Date.new(2014, 05, 26))
+      create(:registration, conference: subject, created_at: Date.new(2014, 0o5, 26))
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 7)
+                            created_at: Date.new(2014, 0o5, 26) + 7)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 14)
+                            created_at: Date.new(2014, 0o5, 26) + 14)
 
       expect(subject.get_registrations_per_week).to eq([1, 2, 3, 3])
     end
 
     it 'summarized correct if there are registrations every week except the first' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 28, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 28, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 7)
+                            created_at: Date.new(2014, 0o5, 26) + 7)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 14)
+                            created_at: Date.new(2014, 0o5, 26) + 14)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 28)
+                            created_at: Date.new(2014, 0o5, 26) + 28)
 
       expect(subject.get_registrations_per_week).to eq([0, 1, 2, 2, 3])
     end
 
     it 'pads left' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 35, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 35, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 21)
+                            created_at: Date.new(2014, 0o5, 26) + 21)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 28)
+                            created_at: Date.new(2014, 0o5, 26) + 28)
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 35)
+                            created_at: Date.new(2014, 0o5, 26) + 35)
 
       expect(subject.get_registrations_per_week).to eq([0, 0, 0, 1, 2, 3])
     end
 
     it 'pads middle' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 35, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 35, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26))
+                            created_at: Date.new(2014, 0o5, 26))
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 35)
+                            created_at: Date.new(2014, 0o5, 26) + 35)
 
       expect(subject.get_registrations_per_week).to eq([1, 1, 1, 1, 1, 2])
     end
 
     it 'pads right' do
       subject.registration_period = create(:registration_period,
-                                           start_date: Date.new(2014, 05, 26),
-                                           end_date: Date.new(2014, 05, 26) + 35, conference: subject)
+                                           start_date: Date.new(2014, 0o5, 26),
+                                           end_date: Date.new(2014, 0o5, 26) + 35, conference: subject)
 
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26))
+                            created_at: Date.new(2014, 0o5, 26))
       create(:registration, conference: subject,
-                            created_at: Date.new(2014, 05, 26) + 7)
+                            created_at: Date.new(2014, 0o5, 26) + 7)
 
       expect(subject.get_registrations_per_week).to eq([1, 2, 2, 2, 2, 2])
     end
   end
 
   describe '#pending?' do
-
     context 'is pending' do
-
       it '#pending? is true' do
         subject.start_date = Date.today + 10
         expect(subject.pending?).to be true
@@ -1412,7 +1400,6 @@ describe Conference do
     end
 
     context 'is not pending' do
-
       it '#pending? is false' do
         subject.start_date = Date.today - 10
         expect(subject.pending?).to be false
@@ -1421,16 +1408,13 @@ describe Conference do
   end
 
   describe '#registration_open?' do
-
     context 'closed registration' do
-
       it '#registration_open? is false' do
         expect(subject.registration_open?).to be false
       end
     end
 
     context 'open registration' do
-
       before do
         subject.end_date = Date.today + 7
         enrollment = create(:registration_period,
@@ -1446,17 +1430,13 @@ describe Conference do
   end
 
   describe '#cfp_open?' do
-
     context 'closed cfp' do
-
       it '#cfp_open? is false' do
         expect(subject.program.cfp_open?).to be false
       end
-
     end
 
     context 'open cfp' do
-
       before do
         create(:cfp, program: subject.program)
       end
@@ -1468,7 +1448,6 @@ describe Conference do
   end
 
   describe '#user_registered?' do
-
     # It is necessary to use bang version of let to build roles before user
     let!(:conference) { create(:conference) }
     let!(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
@@ -1478,13 +1457,13 @@ describe Conference do
 
     context 'user not registered' do
       it '#user_registered? is false' do
-        expect(subject.user_registered? user).to be false
+        expect(subject.user_registered?(user)).to be false
       end
     end
 
     context 'user is nil' do
       it '#user_registered? is false' do
-        expect(subject.user_registered? user).to be false
+        expect(subject.user_registered?(user)).to be false
       end
     end
 
@@ -1496,7 +1475,7 @@ describe Conference do
       end
 
       it '#user_registered? is true' do
-        expect(subject.user_registered? user).to be true
+        expect(subject.user_registered?(user)).to be true
       end
     end
   end
@@ -1544,7 +1523,6 @@ describe Conference do
   end
 
   describe 'validations' do
-
     it 'has a valid factory' do
       expect(build(:conference)).to be_valid
     end
@@ -1598,14 +1576,12 @@ describe Conference do
     end
 
     describe 'valid_date_range?' do
-
       it 'is not valid if start date is greater than end date' do
         expect(subject.start_date).to be <= subject.end_date
       end
     end
 
     describe 'valid_times_range?' do
-
       it 'is not valid if start hour is lower than 0' do
         expect(subject.start_hour).to be >= 0
       end
@@ -1620,7 +1596,6 @@ describe Conference do
     end
 
     describe 'before create callbacks' do
-
       it 'has an email setting after creation' do
         expect(subject.email_settings).not_to be_nil
       end
@@ -1651,13 +1626,13 @@ describe Conference do
     it 'delete event schedules that are not in hour ranges, when conference start hour is updated' do
       scheduled_event_before_conference
       conference.start_hour = conference.start_hour + 1
-      expect{ conference.save }.to change{ EventSchedule.count }.from(2).to(1)
+      expect { conference.save }.to change { EventSchedule.count }.from(2).to(1)
     end
 
     it 'delete event schedules that are not in hour ranges, when conference end hour is updated' do
       scheduled_event_after_conference
       conference.end_hour = conference.end_hour - 2
-      expect{ conference.save }.to change{ EventSchedule.count }.from(2).to(1)
+      expect { conference.save }.to change { EventSchedule.count }.from(2).to(1)
     end
   end
 
@@ -1669,28 +1644,28 @@ describe Conference do
 
     it 'for change in conference' do
       subject.title = 'changed'
-      expect{ subject.save }.to change { subject.revision }.by(1)
+      expect { subject.save }.to change { subject.revision }.by(1)
     end
 
     it 'for change in event' do
       event.title = 'changed'
-      expect{ event.save }.to change { subject.revision }.by(1)
+      expect { event.save }.to change { subject.revision }.by(1)
     end
 
     it 'for change in track' do
       track.name = 'changed'
-      expect{ track.save }.to change { subject.revision }.by(1)
+      expect { track.save }.to change { subject.revision }.by(1)
     end
 
     it 'for change in room' do
       room.name = 'changed'
-      expect{ room.save }.to change { subject.revision }.by(1)
+      expect { room.save }.to change { subject.revision }.by(1)
     end
   end
 
   describe '.upcoming' do
     let!(:upcoming_conference) { create(:conference) }
-    let!(:past_conference) { create(:conference, start_date: Date.current - 1.days, end_date: Date.current - 1.days) }
+    let!(:past_conference) { create(:conference, start_date: Date.current - 1.day, end_date: Date.current - 1.day) }
     subject { Conference.upcoming }
 
     it { is_expected.to eq [upcoming_conference] }
@@ -1698,8 +1673,8 @@ describe Conference do
 
   describe '.past' do
     let!(:upcoming_conference) { create(:conference) }
-    let!(:past_conference1) { create(:conference, start_date: Date.current - 1.days, end_date: Date.current - 1.days) }
-    let!(:past_conference2) { create(:conference, start_date: Date.current - 2.days, end_date: Date.current - 1.days) }
+    let!(:past_conference1) { create(:conference, start_date: Date.current - 1.day, end_date: Date.current - 1.day) }
+    let!(:past_conference2) { create(:conference, start_date: Date.current - 2.days, end_date: Date.current - 1.day) }
     subject { Conference.past }
 
     it { is_expected.to eq [past_conference1, past_conference2] }
diff --git a/spec/models/email_settings_spec.rb b/spec/models/email_settings_spec.rb
index c4ab7830..baabf278 100644
--- a/spec/models/email_settings_spec.rb
+++ b/spec/models/email_settings_spec.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe EmailSettings do
-  let(:conference) { create(:conference, short_title: 'goto', start_date: Date.new(2014, 05, 01), end_date: Date.new(2014, 05, 06)) }
+  let(:conference) { create(:conference, short_title: 'goto', start_date: Date.new(2014, 0o5, 0o1), end_date: Date.new(2014, 0o5, 0o6)) }
   let(:user) { create(:user, username: 'johnd', email: 'john@doe.com', name: 'John Doe') }
   let(:event) { create(:event, program: conference.program, title: 'Talk about talks', submitter: user) }
   let(:expected_hash) do
@@ -9,8 +11,8 @@ describe EmailSettings do
       'email' => 'john@doe.com',
       'name' => 'John Doe',
       'conference' => conference.title,
-      'conference_start_date' => Date.new(2014, 05, 01),
-      'conference_end_date' => Date.new(2014, 05, 06),
+      'conference_start_date' => Date.new(2014, 0o5, 0o1),
+      'conference_end_date' => Date.new(2014, 0o5, 0o6),
       'registrationlink' => 'http://localhost:3000/conferences/goto/register',
       'conference_splash_link' => 'http://localhost:3000/conferences/goto',
       'schedule_link' => 'http://localhost:3000/conferences/goto/schedule',
@@ -34,7 +36,7 @@ describe EmailSettings do
 
     context 'user does not have name' do
       before do
-        user.update_attributes(name: nil)
+        user.update(name: nil)
         username_hash = { 'name' => 'johnd' }
         expected_hash.merge!(username_hash)
       end
@@ -47,10 +49,10 @@ describe EmailSettings do
     context 'conference has cfp' do
       before do
         create(:cfp,
-               start_date: Date.new(2014, 04, 29),
-               end_date: Date.new(2014, 05, 06),
+               start_date: Date.new(2014, 0o4, 29),
+               end_date: Date.new(2014, 0o5, 0o6),
                program: conference.program)
-        cfp_dates_hash = { 'cfp_start_date' => Date.new(2014, 04, 29), 'cfp_end_date' => Date.new(2014, 05, 06) }
+        cfp_dates_hash = { 'cfp_start_date' => Date.new(2014, 0o4, 29), 'cfp_end_date' => Date.new(2014, 0o5, 0o6) }
         expected_hash.merge!(cfp_dates_hash)
       end
 
@@ -61,7 +63,7 @@ describe EmailSettings do
 
     context 'conference has venue' do
       before do
-        conference.update_attributes(venue: create(:venue))
+        conference.update(venue: create(:venue))
         venue_hash = { 'venue' => conference.venue.name, 'venue_address' => conference.venue.address }
         expected_hash.merge!(venue_hash)
       end
@@ -73,10 +75,10 @@ describe EmailSettings do
 
     context 'conference has registration period' do
       before do
-        conference.update_attributes(registration_period: create(:registration_period,
-                                                                 start_date: Date.new(2014, 05, 03),
-                                                                 end_date: Date.new(2014, 05, 05)))
-        registration_period_hash = { 'registration_start_date' => Date.new(2014, 05, 03), 'registration_end_date' => Date.new(2014, 05, 05) }
+        conference.update(registration_period: create(:registration_period,
+                                                      start_date: Date.new(2014, 0o5, 0o3),
+                                                      end_date: Date.new(2014, 0o5, 0o5)))
+        registration_period_hash = { 'registration_start_date' => Date.new(2014, 0o5, 0o3), 'registration_end_date' => Date.new(2014, 0o5, 0o5) }
         expected_hash.merge!(registration_period_hash)
       end
 
diff --git a/spec/models/event_schedule_spec.rb b/spec/models/event_schedule_spec.rb
index 91db4b64..56cedcd4 100644
--- a/spec/models/event_schedule_spec.rb
+++ b/spec/models/event_schedule_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe EventSchedule do
diff --git a/spec/models/event_spec.rb b/spec/models/event_spec.rb
index 158e1db3..5885fea9 100644
--- a/spec/models/event_spec.rb
+++ b/spec/models/event_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Event do
@@ -295,7 +297,7 @@ describe Event do
     it 'counts words in abstract' do
       event = build(:event)
       expect(event.abstract_word_count).to eq(event.abstract.to_s.split.size)
-      event.update_attributes!(abstract: 'abstract.')
+      event.update!(abstract: 'abstract.')
       expect(event.abstract_word_count).to eq(1)
     end
 
@@ -315,16 +317,15 @@ describe Event do
       end
     end
 
-    states = [:new, :withdrawn, :unconfirmed, :confirmed, :canceled, :rejected]
-    transitions = [:restart, :withdraw, :accept, :confirm, :cancel, :reject]
+    states = %i[new withdrawn unconfirmed confirmed canceled rejected]
+    transitions = %i[restart withdraw accept confirm cancel reject]
 
-    states_transitions = { new: { restart: false, withdraw: true, accept: true, confirm: false, cancel: false, reject: true},
-                           withdrawn: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false},
-                           unconfirmed: { restart: false, withdraw: true, accept: false, confirm: true, cancel: true, reject: false},
-                           confirmed: { restart: false, withdraw: true, accept: false, confirm: false, cancel: true, reject: false},
-                           canceled: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false},
-                           rejected: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false}
-                         }
+    states_transitions = { new: { restart: false, withdraw: true, accept: true, confirm: false, cancel: false, reject: true },
+                           withdrawn: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false },
+                           unconfirmed: { restart: false, withdraw: true, accept: false, confirm: true, cancel: true, reject: false },
+                           confirmed: { restart: false, withdraw: true, accept: false, confirm: false, cancel: true, reject: false },
+                           canceled: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false },
+                           rejected: { restart: true, withdraw: false, accept: false, confirm: false, cancel: false, reject: false } }
 
     states.each do |state|
       transitions.each do |transition|
diff --git a/spec/models/event_type_spec.rb b/spec/models/event_type_spec.rb
index 6863ed8e..9fb65950 100644
--- a/spec/models/event_type_spec.rb
+++ b/spec/models/event_type_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe EventType do
diff --git a/spec/models/openid.rb b/spec/models/openid.rb
index 42b6a74f..ce029b82 100644
--- a/spec/models/openid.rb
+++ b/spec/models/openid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Openid do
diff --git a/spec/models/organization_spec.rb b/spec/models/organization_spec.rb
index ca84f532..b9d78b7d 100644
--- a/spec/models/organization_spec.rb
+++ b/spec/models/organization_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Organization do
diff --git a/spec/models/payment_spec.rb b/spec/models/payment_spec.rb
index 6af28679..51fc2dec 100644
--- a/spec/models/payment_spec.rb
+++ b/spec/models/payment_spec.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 require 'stripe_mock'
 
 describe Payment do
-
   context 'new payment' do
     let(:payment) { create(:payment) }
     it 'sets status to "unpaid" by default' do
@@ -38,7 +39,7 @@ describe Payment do
     let!(:user) { create(:user) }
     let!(:conference) { create(:conference) }
     let!(:ticket_1) { create(:ticket, price: 10, price_currency: 'USD', conference: conference) }
-    let!(:tickets) { {ticket_1.id.to_s => '2'} }
+    let!(:tickets) { { ticket_1.id.to_s => '2' } }
     let(:stripe_helper) { StripeMock.create_test_helper }
 
     before { StripeMock.start }
@@ -90,42 +91,42 @@ describe Payment do
       context 'when the connection to Stripe drops' do
         it 'raises exception' do
           StripeMock.prepare_error(Stripe::APIConnectionError.new)
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
 
       context 'when there is a Stripe API Error' do
         it 'raises exception' do
           StripeMock.prepare_error(Stripe::APIError.new)
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
 
       context 'when there is authentication error' do
         it 'raises exception' do
           StripeMock.prepare_error(Stripe::AuthenticationError.new)
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
 
       context 'when there is a card error' do
         it 'raises exception' do
           StripeMock.prepare_card_error(:card_declined)
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
 
       context 'when the request to Stripe is invalid' do
         it 'raises exception' do
           StripeMock.prepare_error(Stripe::InvalidRequestError.new('Your request is invalid.', code: 402))
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
 
       context 'when Stripe rate limit exceeds' do
         it 'raises exception' do
           StripeMock.prepare_error(Stripe::RateLimitError.new)
-          expect{ payment.purchase }.not_to raise_error
+          expect { payment.purchase }.not_to raise_error
         end
       end
     end
diff --git a/spec/models/physical_ticket_spec.rb b/spec/models/physical_ticket_spec.rb
index 9910a4a3..4a64ca48 100644
--- a/spec/models/physical_ticket_spec.rb
+++ b/spec/models/physical_ticket_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe PhysicalTicket do
-
   describe 'association' do
     it { is_expected.to belong_to :ticket_purchase }
   end
diff --git a/spec/models/program_spec.rb b/spec/models/program_spec.rb
index a4b7e44f..76affe73 100644
--- a/spec/models/program_spec.rb
+++ b/spec/models/program_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Program do
@@ -198,8 +200,8 @@ describe Program do
       program.schedule_interval = 5
       program.save!
 
-      program.event_types.first.update_attributes length: 5
-      program.event_types.last.update_attributes length: 25
+      program.event_types.first.update length: 5
+      program.event_types.last.update length: 25
       create(:event_type, program: program, length: 30)
 
       program.schedule_interval = 10
@@ -237,13 +239,12 @@ describe Program do
   describe '#languages_list' do
     it 'returns the list of readable languages' do
       program.languages = 'en,de,fr,ru,zh'
-      expect(program.languages_list).to eq %w(English German French Russian Chinese)
+      expect(program.languages_list).to eq %w[English German French Russian Chinese]
     end
   end
 
   describe '#any_event_for_this_date?' do
-
-    let(:event){ create(:event, program: program) }
+    let(:event) { create(:event, program: program) }
 
     context 'when no schedule is selected for the conference' do
       let(:schedule) { create(:schedule, program: program) }
diff --git a/spec/models/registration_period_spec.rb b/spec/models/registration_period_spec.rb
index 52fb3755..10da0684 100644
--- a/spec/models/registration_period_spec.rb
+++ b/spec/models/registration_period_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe RegistrationPeriod do
diff --git a/spec/models/registration_spec.rb b/spec/models/registration_spec.rb
index e7824c08..f6ff6b68 100644
--- a/spec/models/registration_spec.rb
+++ b/spec/models/registration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'Registration' do
@@ -61,7 +63,7 @@ describe 'Registration' do
   end
 
   describe '#week' do
-    before { subject.created_at = Date.new(2014, 06, 30) }
+    before { subject.created_at = Date.new(2014, 0o6, 30) }
 
     it 'returns week number of created_at' do
       expect(subject.week).to eq(26)
diff --git a/spec/models/resource_spec.rb b/spec/models/resource_spec.rb
index 03a6a502..d70e3144 100644
--- a/spec/models/resource_spec.rb
+++ b/spec/models/resource_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Resource do
diff --git a/spec/models/role_spec.rb b/spec/models/role_spec.rb
index db2b04f9..5edeb8e8 100644
--- a/spec/models/role_spec.rb
+++ b/spec/models/role_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Role do
diff --git a/spec/models/room_spec.rb b/spec/models/room_spec.rb
index f135f91d..5aa79643 100644
--- a/spec/models/room_spec.rb
+++ b/spec/models/room_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Room do
diff --git a/spec/models/schedule_spec.rb b/spec/models/schedule_spec.rb
index 2dc1b826..228da101 100644
--- a/spec/models/schedule_spec.rb
+++ b/spec/models/schedule_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Schedule do
-
   describe 'association' do
     it { should belong_to(:program) }
     it { should belong_to(:track) }
diff --git a/spec/models/sponsor_spec.rb b/spec/models/sponsor_spec.rb
index 1cd36cff..7f6e3e50 100644
--- a/spec/models/sponsor_spec.rb
+++ b/spec/models/sponsor_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Sponsor do
diff --git a/spec/models/sponsorship_level_spec.rb b/spec/models/sponsorship_level_spec.rb
index 2284d4ba..4674fd01 100644
--- a/spec/models/sponsorship_level_spec.rb
+++ b/spec/models/sponsorship_level_spec.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe SponsorshipLevel do
   describe 'validation' do
-
     it 'has a valid factory' do
       expect(build(:sponsorship_level)).to be_valid
     end
diff --git a/spec/models/target_spec.rb b/spec/models/target_spec.rb
index 5297cabc..501c1c4c 100644
--- a/spec/models/target_spec.rb
+++ b/spec/models/target_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Target do
diff --git a/spec/models/ticket_purchase_spec.rb b/spec/models/ticket_purchase_spec.rb
index bfca5efc..3cbb24bd 100644
--- a/spec/models/ticket_purchase_spec.rb
+++ b/spec/models/ticket_purchase_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe TicketPurchase do
-
   describe 'validations' do
     it 'has a valid factory' do
       expect(build(:ticket_purchase)).to be_valid
diff --git a/spec/models/ticket_scanning_spec.rb b/spec/models/ticket_scanning_spec.rb
index 3d978f4f..ce18e63e 100644
--- a/spec/models/ticket_scanning_spec.rb
+++ b/spec/models/ticket_scanning_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe TicketScanning do
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
index cf6f4ae4..aacc8eb6 100644
--- a/spec/models/ticket_spec.rb
+++ b/spec/models/ticket_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Ticket do
@@ -6,7 +8,6 @@ describe Ticket do
   let(:user) { create(:user) }
 
   describe 'validation' do
-
     it 'has a valid factory' do
       expect(build(:ticket)).to be_valid
     end
@@ -80,14 +81,13 @@ describe Ticket do
     let!(:ticket_purchase) { create(:ticket_purchase, user: user, ticket: ticket) }
 
     context 'user has not paid' do
-
       it 'returns true' do
         expect(ticket.unpaid?(user)).to eq(true)
       end
     end
 
     context 'user has paid' do
-      before { ticket_purchase.update_attributes(paid: true) }
+      before { ticket_purchase.update(paid: true) }
 
       it 'returns false' do
         expect(ticket.unpaid?(user)).to eq(false)
@@ -123,7 +123,7 @@ describe Ticket do
 
     context 'user has paid' do
       let!(:ticket_purchase) { create(:ticket_purchase, user: user, ticket: ticket, quantity: 20) }
-      before { ticket_purchase.update_attributes(paid: true) }
+      before { ticket_purchase.update(paid: true) }
 
       it 'returns the correct value if the user has bought and paid for this ticket' do
         expect(ticket.quantity_bought_by(user, paid: true)).to eq(20)
@@ -138,7 +138,7 @@ describe Ticket do
                user: user,
                ticket: ticket,
                quantity: 20)
-        expect(ticket.total_price(user, paid: false)).to eq(Money.new(100000, 'USD'))
+        expect(ticket.total_price(user, paid: false)).to eq(Money.new(100_000, 'USD'))
       end
 
       it 'returns zero if the user has not bought this ticket' do
@@ -148,10 +148,10 @@ describe Ticket do
 
     context 'user has paid' do
       let!(:ticket_purchase) { create(:ticket_purchase, user: user, ticket: ticket, quantity: 20) }
-      before { ticket_purchase.update_attributes(paid: true) }
+      before { ticket_purchase.update(paid: true) }
 
       it 'returns the correct value if the user has bought this ticket' do
-        expect(ticket.total_price(user, paid: true)).to eq(Money.new(100000, 'USD'))
+        expect(ticket.total_price(user, paid: true)).to eq(Money.new(100_000, 'USD'))
       end
     end
   end
@@ -172,7 +172,7 @@ describe Ticket do
         end
 
         it 'returns the correct total price' do
-          expect(Ticket.total_price(conference, user, paid: false)).to eq(Money.new(100000, 'USD'))
+          expect(Ticket.total_price(conference, user, paid: false)).to eq(Money.new(100_000, 'USD'))
         end
       end
 
@@ -183,7 +183,7 @@ describe Ticket do
         end
 
         it 'returns the correct total price' do
-          total_price = Money.new(200000, 'USD')
+          total_price = Money.new(200_000, 'USD')
           expect(Ticket.total_price(conference, user, paid: false)).to eq(total_price)
         end
       end
@@ -206,7 +206,7 @@ describe Ticket do
 
       it 'should allow currency update' do
         free_ticket = Ticket.first
-        expect { free_ticket.update_attributes(price_currency: 'INR') }.to change { free_ticket.reload.price_currency }.from('USD').to('INR')
+        expect { free_ticket.update(price_currency: 'INR') }.to change { free_ticket.reload.price_currency }.from('USD').to('INR')
       end
     end
   end
diff --git a/spec/models/track_spec.rb b/spec/models/track_spec.rb
index 10b92462..420e6306 100644
--- a/spec/models/track_spec.rb
+++ b/spec/models/track_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Track do
@@ -321,8 +323,8 @@ describe Track do
       end
     end
 
-    states = [:new, :to_accept, :accepted, :confirmed, :to_reject, :rejected, :canceled, :withdrawn]
-    transitions = [:restart, :to_accept, :accept, :confirm, :to_reject, :reject, :cancel, :withdraw]
+    states = %i[new to_accept accepted confirmed to_reject rejected canceled withdrawn]
+    transitions = %i[restart to_accept accept confirm to_reject reject cancel withdraw]
 
     states_transitions = { new: { restart: false, to_accept: true, accept: true, confirm: false, to_reject: true, reject: true, cancel: false, withdraw: true },
                            to_accept: { restart: false, to_accept: false, accept: true, confirm: false, to_reject: true, reject: false, cancel: true, withdraw: true },
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 019263ac..f6f222f9 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe User do
-
   let(:user_admin) { create(:admin) }
   let(:conference) { create(:conference, short_title: 'oSC16', title: 'openSUSE Conference 2016') }
   let(:conference2) { create(:conference, short_title: 'oSC15', title: 'openSUSE Conference 2015') }
@@ -103,7 +104,7 @@ describe User do
     describe '#attended_event?' do
       context 'user has attended to the event' do
         before do
-          events_registration.update_attributes(attended: true)
+          events_registration.update(attended: true)
         end
 
         it 'returns true' do
@@ -186,7 +187,7 @@ describe User do
     end
 
     describe '.for_ichain_username' do
-      before { user.update_attributes(current_sign_in_at: Date.new(2014, 12, 12)) }
+      before { user.update(current_sign_in_at: Date.new(2014, 12, 12)) }
 
       context 'user exists' do
         it 'updates last_sign_in_at of user' do
@@ -205,10 +206,10 @@ describe User do
       end
 
       context 'user is disabled' do
-        before { user.update_attributes(is_disabled: true) }
+        before { user.update(is_disabled: true) }
 
         it 'User.for_ichain_username raises exception if user is disabled' do
-          expect{ User.for_ichain_username(user.username, email: user.email) }
+          expect { User.for_ichain_username(user.username, email: user.email) }
             .to raise_error(UserDisabled)
         end
       end
@@ -217,14 +218,14 @@ describe User do
     describe '.find_for_database_authentication' do
       context 'login with username' do
         it 'can find user by jumbled username' do
-          scrambled_username = user.username.chars.map{|c| rand > 0.5 ? c.capitalize : c}.join
+          scrambled_username = user.username.chars.map { |c| rand > 0.5 ? c.capitalize : c }.join
           expect(User.find_for_database_authentication(login: scrambled_username)).to eq(user)
         end
       end
 
       context 'login with email' do
         it 'can find user by jumbled email' do
-          scrambled_email = user.email.chars.map{|c| rand > 0.5 ? c.capitalize : c}.join
+          scrambled_email = user.email.chars.map { |c| rand > 0.5 ? c.capitalize : c }.join
           expect(User.find_for_database_authentication(login: scrambled_email)).to eq(user)
         end
       end
@@ -242,8 +243,7 @@ describe User do
                                credentials: {
                                  token: 'mock_token',
                                  secret: 'mock_secret'
-                               }
-                              )
+                               })
       end
 
       context 'user is not signed in' do
@@ -277,7 +277,7 @@ describe User do
       let(:conf2_organizer_role) { Role.find_by(name: 'organizer', resource: conference2) }
 
       before do
-        user.update_attributes(role_ids: [organizer_role.id, cfp_role.id, conf2_organizer_role.id])
+        user.update(role_ids: [organizer_role.id, cfp_role.id, conf2_organizer_role.id])
       end
 
       it 'returns hash of role and conference' do
@@ -336,7 +336,7 @@ describe User do
       end
 
       context 'unconfirmed user' do
-        before { user.update_attributes(confirmed_at: nil) }
+        before { user.update(confirmed_at: nil) }
 
         it 'returns false' do
           expect(user.confirmed?).to eq false
@@ -450,7 +450,7 @@ describe User do
 
   describe '.omniauth_providers' do
     it 'contains providers' do
-      expect(User.omniauth_providers).to eq [:suse, :google, :facebook, :github]
+      expect(User.omniauth_providers).to eq %i[suse google facebook github]
     end
   end
 end
diff --git a/spec/routing/routing_spec.rb b/spec/routing/routing_spec.rb
index 1875150f..8f1d5dff 100644
--- a/spec/routing/routing_spec.rb
+++ b/spec/routing/routing_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 feature 'Routing', type: :routing do
diff --git a/spec/serializers/conference_serializer_spec.rb b/spec/serializers/conference_serializer_spec.rb
index 851c6518..163f4f8f 100644
--- a/spec/serializers/conference_serializer_spec.rb
+++ b/spec/serializers/conference_serializer_spec.rb
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe ConferenceSerializer, type: :serializer do
   let(:conference) do
     create(:conference, short_title: 'goto',
                         description: 'Lorem ipsum dolor sit',
-                        start_date: Date.new(2014, 03, 04),
-                        end_date: Date.new(2014, 03, 10))
+                        start_date: Date.new(2014, 0o3, 0o4),
+                        end_date: Date.new(2014, 0o3, 10))
   end
 
   let(:serializer) { ConferenceSerializer.new(conference) }
diff --git a/spec/serializers/event_serializer_spec.rb b/spec/serializers/event_serializer_spec.rb
index 8bb29fa2..ca28720b 100644
--- a/spec/serializers/event_serializer_spec.rb
+++ b/spec/serializers/event_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 describe EventSerializer, type: :serializer do
   let(:event) { create(:event, title: 'Some Talk', abstract: 'Lorem ipsum dolor sit amet') }
@@ -32,7 +34,7 @@ describe EventSerializer, type: :serializer do
     before do
       event.language = 'English'
       event.speakers = [speaker]
-      create(:event_schedule, event: event, room: room, start_time: Date.new(2014, 03, 04) + 9.hours)
+      create(:event_schedule, event: event, room: room, start_time: Date.new(2014, 0o3, 0o4) + 9.hours)
       event.track = track
     end
 
diff --git a/spec/serializers/room_serializer_spec.rb b/spec/serializers/room_serializer_spec.rb
index 5b7467cc..28da2594 100644
--- a/spec/serializers/room_serializer_spec.rb
+++ b/spec/serializers/room_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 describe RoomSerializer, type: :serializer do
   let(:room) { create(:room) }
diff --git a/spec/serializers/speaker_serializer_spec.rb b/spec/serializers/speaker_serializer_spec.rb
index 74545709..d83687c7 100644
--- a/spec/serializers/speaker_serializer_spec.rb
+++ b/spec/serializers/speaker_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 describe SpeakerSerializer, type: :serializer do
   let(:speaker) { create(:user, name: 'John Doe', affiliation: 'JohnDoesInc', biography: nil) }
@@ -18,7 +20,7 @@ describe SpeakerSerializer, type: :serializer do
   end
 
   context 'speaker has biography' do
-    before{ speaker.update_attributes(biography: 'Doest of all Jon Does') }
+    before { speaker.update(biography: 'Doest of all Jon Does') }
 
     it 'sets name, affiliation and biography' do
       expected_json = {
diff --git a/spec/serializers/track_serializer_spec.rb b/spec/serializers/track_serializer_spec.rb
index 00522eae..d29cf43f 100644
--- a/spec/serializers/track_serializer_spec.rb
+++ b/spec/serializers/track_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe TrackSerializer, type: :serializer do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 60e07602..9fac2a9f 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file is copied to spec/ when you run 'rails generate rspec:install'
 require 'simplecov'
 
@@ -10,7 +12,7 @@ else
 end
 
 ENV['RAILS_ENV'] ||= 'test'
-require File.expand_path('../../config/environment', __FILE__)
+require File.expand_path('../config/environment', __dir__)
 
 require 'rspec/rails'
 require 'shoulda/matchers'
diff --git a/spec/support/api_schema_matcher.rb b/spec/support/api_schema_matcher.rb
index 4da6bfe6..8027a46d 100644
--- a/spec/support/api_schema_matcher.rb
+++ b/spec/support/api_schema_matcher.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Source: https://robots.thoughtbot.com/validating-json-schemas-with-an-rspec-matcher
 
 RSpec::Matchers.define :match_response_schema do |schema|
diff --git a/spec/support/database_cleaner.rb b/spec/support/database_cleaner.rb
index 25bf528a..4162529c 100644
--- a/spec/support/database_cleaner.rb
+++ b/spec/support/database_cleaner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.configure do |config|
   config.before(:suite) do
     DatabaseCleaner.clean_with(:truncation)
diff --git a/spec/support/external_request.rb b/spec/support/external_request.rb
index ed7da3d3..1212d20c 100644
--- a/spec/support/external_request.rb
+++ b/spec/support/external_request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Mock external requests to youtube
 require 'webmock/rspec'
 WebMock.disable_net_connect!(allow_localhost: true, allow: /stripe.com/)
@@ -25,5 +27,5 @@ def mock_commercial_request
     height: 344
   }
   WebMock.stub_request(:get, /.*youtube.*/)
-    .to_return(status: 200, body: response.to_json, headers: {})
+         .to_return(status: 200, body: response.to_json, headers: {})
 end
diff --git a/spec/support/factory_girl.rb b/spec/support/factory_girl.rb
index d745aece..4ff64b13 100644
--- a/spec/support/factory_girl.rb
+++ b/spec/support/factory_girl.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 require_relative 'external_request'
 
 RSpec.configure do |config|
-
   config.before(:suite) do
     if ENV['OSEM_FACTORY_LINT'] != 'false'
       DatabaseCleaner.strategy = :transaction
diff --git a/spec/support/flash.rb b/spec/support/flash.rb
index e999decc..d94f4fdb 100644
--- a/spec/support/flash.rb
+++ b/spec/support/flash.rb
@@ -1,12 +1,12 @@
+# frozen_string_literal: true
+
 module Flash
   def flash
     results = all(:css, 'div#flash p')
-    if results.empty?
-      return 'none'
-    end
+    return 'none' if results.empty?
     if results.count > 1
-      texts = results.map { |r| r.text }
-      fail "One flash expected, but we had #{texts.inspect}"
+      texts = results.map(&:text)
+      raise "One flash expected, but we had #{texts.inspect}"
     end
     results.first.text
   end
diff --git a/spec/support/kneet_connections.rb b/spec/support/kneet_connections.rb
index 99c91fd3..87f0bcd5 100644
--- a/spec/support/kneet_connections.rb
+++ b/spec/support/kneet_connections.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   class Base
     mattr_accessor :shared_connection
diff --git a/spec/support/login_macros.rb b/spec/support/login_macros.rb
index 67b9743c..7557c14d 100644
--- a/spec/support/login_macros.rb
+++ b/spec/support/login_macros.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module LoginMacros
   include Warden::Test::Helpers
   Warden.test_mode!
diff --git a/spec/support/omniauth_macros.rb b/spec/support/omniauth_macros.rb
index 47ff191e..54500903 100644
--- a/spec/support/omniauth_macros.rb
+++ b/spec/support/omniauth_macros.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OmniauthMacros
   # The mock_auth configuration allows you to set per-provider (or default)
   # authentication hashes to return during integration testing.
@@ -14,33 +16,33 @@ module OmniauthMacros
   def mock_auth_new_user
     OmniAuth.config.mock_auth[:google] =
       OmniAuth::AuthHash.new(
-                              provider: 'google',
-                              uid: 'google-test-uid-1',
-                              info: {
-                                name: 'new user name',
-                                email: 'test-1@example.com'
-                              },
-                              credentials: {
-                                token: 'mock_token',
-                                secret: 'mock_secret'
-                              }
-                            )
+        provider: 'google',
+        uid: 'google-test-uid-1',
+        info: {
+          name: 'new user name',
+          email: 'test-1@example.com'
+        },
+        credentials: {
+          token: 'mock_token',
+          secret: 'mock_secret'
+        }
+      )
   end
 
   def mock_auth_new_user_fb
     OmniAuth.config.mock_auth[:facebook] =
       OmniAuth::AuthHash.new(
-                              provider: 'facebook',
-                              uid: 'facebook-test-uid-1',
-                              info: {
-                                name: 'new user fb name',
-                                email: 'test-1@example.com'
-                              },
-                              credentials: {
-                                token: 'mock_token',
-                                secret: 'mock_secret'
-                              }
-                            )
+        provider: 'facebook',
+        uid: 'facebook-test-uid-1',
+        info: {
+          name: 'new user fb name',
+          email: 'test-1@example.com'
+        },
+        credentials: {
+          token: 'mock_token',
+          secret: 'mock_secret'
+        }
+      )
   end
 
   def mock_auth_existing_user_participant
@@ -48,17 +50,17 @@ module OmniauthMacros
     # authentication hashes to return during integration testing.
     OmniAuth.config.mock_auth[:google] =
       OmniAuth::AuthHash.new(
-                              provider: 'google',
-                              uid: 'google-test-uid-participant-1',
-                              info: {
-                                name: 'existing user participant name',
-                                email: 'test-participant-1@example.com'
-                              },
-                              credentials: {
-                                token: 'mock_token',
-                                secret: 'mock_secret'
-                              }
-                            )
+        provider: 'google',
+        uid: 'google-test-uid-participant-1',
+        info: {
+          name: 'existing user participant name',
+          email: 'test-participant-1@example.com'
+        },
+        credentials: {
+          token: 'mock_token',
+          secret: 'mock_secret'
+        }
+      )
   end
 
   def mock_auth_existing_user_admin
@@ -66,17 +68,17 @@ module OmniauthMacros
     # authentication hashes to return during integration testing.
     OmniAuth.config.mock_auth[:google] =
       OmniAuth::AuthHash.new(
-                              provider: 'google',
-                              uid: 'google-test-uid-admin-1',
-                              info: {
-                                name: 'existing user admin name',
-                                email: 'test-admin-1@example.com'
-                              },
-                              credentials: {
-                                token: 'mock_token',
-                                secret: 'mock_secret'
-                              }
-                            )
+        provider: 'google',
+        uid: 'google-test-uid-admin-1',
+        info: {
+          name: 'existing user admin name',
+          email: 'test-admin-1@example.com'
+        },
+        credentials: {
+          token: 'mock_token',
+          secret: 'mock_secret'
+        }
+      )
   end
 
   # We use these mock accounts to ensure that the ones which are available in
@@ -87,62 +89,62 @@ module OmniauthMacros
   def mock_auth_accounts
     OmniAuth.config.mock_auth[:facebook] =
       OmniAuth::AuthHash.new(
-                              provider: 'facebook',
-                              uid: 'facebook-test-uid-1',
-                              info: {
-                                name: 'facebook user',
-                                email: 'user-facebook@example.com',
-                                username: 'user_facebook'
-                              },
-                              credentials: {
-                                token: 'fb_mock_token',
-                                secret: 'fb_mock_secret'
-                              }
-                            )
+        provider: 'facebook',
+        uid: 'facebook-test-uid-1',
+        info: {
+          name: 'facebook user',
+          email: 'user-facebook@example.com',
+          username: 'user_facebook'
+        },
+        credentials: {
+          token: 'fb_mock_token',
+          secret: 'fb_mock_secret'
+        }
+      )
 
     OmniAuth.config.mock_auth[:google] =
       OmniAuth::AuthHash.new(
-                              provider: 'google',
-                              uid: 'google-test-uid-1',
-                              info: {
-                                name: 'google user',
-                                email: 'user-google@example.com',
-                                username: 'user_google'
-                              },
-                              credentials: {
-                                token: 'google_mock_token',
-                                secret: 'google_mock_secret'
-                              }
-                            )
+        provider: 'google',
+        uid: 'google-test-uid-1',
+        info: {
+          name: 'google user',
+          email: 'user-google@example.com',
+          username: 'user_google'
+        },
+        credentials: {
+          token: 'google_mock_token',
+          secret: 'google_mock_secret'
+        }
+      )
 
     OmniAuth.config.mock_auth[:suse] =
       OmniAuth::AuthHash.new(
-                              provider: 'suse',
-                              uid: 'suse-test-uid-1',
-                              info: {
-                                name: 'suse user',
-                                email: 'user-suse@example.com',
-                                username: 'user_suse'
-                              },
-                              credentials: {
-                                token: 'suse_mock_token',
-                                secret: 'suse_mock_secret'
-                              }
-                            )
+        provider: 'suse',
+        uid: 'suse-test-uid-1',
+        info: {
+          name: 'suse user',
+          email: 'user-suse@example.com',
+          username: 'user_suse'
+        },
+        credentials: {
+          token: 'suse_mock_token',
+          secret: 'suse_mock_secret'
+        }
+      )
 
     OmniAuth.config.mock_auth[:github] =
       OmniAuth::AuthHash.new(
-                              provider: 'github',
-                              uid: 'github-test-uid-1',
-                              info: {
-                                name: 'github user',
-                                email: 'user-github@example.com',
-                                username: 'user_github'
-                              },
-                              credentials: {
-                                token: 'github_mock_token',
-                                secret: 'github_mock_secret'
-                              }
-                            )
+        provider: 'github',
+        uid: 'github-test-uid-1',
+        info: {
+          name: 'github user',
+          email: 'user-github@example.com',
+          username: 'user_github'
+        },
+        credentials: {
+          token: 'github_mock_token',
+          secret: 'github_mock_secret'
+        }
+      )
   end
 end
diff --git a/spec/support/save_feature_failures.rb b/spec/support/save_feature_failures.rb
index 2e0d33a9..432853b6 100644
--- a/spec/support/save_feature_failures.rb
+++ b/spec/support/save_feature_failures.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Automatically save the page a test fails
 Capybara.save_and_open_page_path = Rails.root.join('tmp', 'capybara')
 
diff --git a/spec/support/sidebar.rb b/spec/support/sidebar.rb
index 5d90ee42..47d9507d 100644
--- a/spec/support/sidebar.rb
+++ b/spec/support/sidebar.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Sidebar
   def sidebar
     @conference = create(:conference)