Use Ruby safe navigation over Rails try

re: https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Style/SafeNavigation

.rubocop.yml

@@ -17,8 +17,6 @@ AllCops:
 #################### Metrics ###############################
 
 # Start with cops for Ruby >= 2.3 disabled
-Style/SafeNavigation:
-  Enabled: false
 Style/NumericPredicate:
   Enabled: false
 

app/models/ability.rb

@@ -20,7 +20,7 @@ class Ability
     can [:index, :conferences, :code_of_conduct], Organization
     can [:index], Conference
     can [:show], Conference do |conference|
-      conference.splashpage && conference.splashpage.public == true
+      conference.splashpage&.public == true
     end
     # Can view the schedule
     can [:schedule, :events], Conference do |conference|

app/models/cfp.rb

@@ -108,14 +108,18 @@ 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&.end_date && end_date && (end_date > program.conference.end_date)
-      errors
+      errors.add(
-      .add(:end_date, "can't be after the conference end date (#{program.conference.end_date})")
+        :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&.end_date && start_date && (start_date > program.conference.end_date)
-      errors
+      errors.add(
-      .add(:start_date, "can't be after the conference end date (#{program.conference.end_date})")
+        :start_date,
+        "can't be after the conference end date (#{program.conference.end_date})"
+      )
     end
   end
 

app/models/conference.rb

@@ -154,7 +154,7 @@ 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
@@ -171,7 +171,7 @@ 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
@@ -272,9 +272,8 @@ class Conference < ApplicationRecord
   def registration_weeks
     result = 0
     weeks = 0
-    if registration_period &&
+    if registration_period&.start_date &&
-        registration_period.start_date &&
+        registration_period&.end_date
-        registration_period.end_date
       weeks = Date.new(registration_period.start_date.year, 12, 31)
           .strftime('%W').to_i
 
@@ -346,7 +345,7 @@ 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(

app/models/event.rb

@@ -312,7 +312,7 @@ class Event < ApplicationRecord
 
   def before_end_of_conference
     errors
-        .add(:created_at, "can't be after the conference end date!") if program.conference && program.conference.end_date &&
+        .add(:created_at, "can't be after the conference end date!") if program.conference&.end_date &&
         (Date.today > program.conference.end_date)
   end
 
@@ -324,7 +324,7 @@ 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
 

app/models/registration_period.rb

@@ -13,10 +13,10 @@ class RegistrationPeriod < ApplicationRecord
 
   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)
+    .add(:start_date, "can't be after the conference end date (#{conference.end_date})") if conference&.end_date && start_date && (start_date > conference.end_date)
 
     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)
+    .add(:end_date, "can't be after the conference end date (#{conference.end_date})") if conference&.end_date && end_date && (end_date > conference.end_date)
   end
 
   def start_date_before_end_date

app/models/track.rb

@@ -115,10 +115,8 @@ class Track < ApplicationRecord
   def revoke_role_and_cleanup
     role = Role.find_by(name: 'track_organizer', resource: self)
 
-    if role
+    role&.users&.each do |user|
-      role.users.each do |user|
+      user.remove_role 'track_organizer', self
-        user.remove_role 'track_organizer', self
-      end
     end
 
     self.selected_schedule_id = nil

app/models/user.rb

@@ -133,7 +133,7 @@ class User < ApplicationRecord
   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],

app/models/venue.rb

@@ -21,7 +21,7 @@ class Venue < ApplicationRecord
 
   def country_name
     name = ISO3166::Country[country]
-    name.name if name
+    name&.name
   end
 
   def location?

app/uploaders/picture_uploader.rb

@@ -44,7 +44,7 @@ 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.

db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb

@@ -19,7 +19,7 @@ class MigrateDataRemoveColumnIncludeCfpInSplashAddColumnIncludeCfp < ActiveRecor
     TempConference.all.each do |conference|
       cfp = TempCallForPaper.find_by(conference_id: conference.id)
 
-      if cfp && cfp.include_cfp_in_splash
+      if 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!