Merge pull request #370 from ChrisBr/fix_migration

Assert event not deleted on add_events_per_week migration

db/migrate/20140701123203_add_events_per_week_to_conference.rb

@@ -17,8 +17,10 @@ class AddEventsPerWeekToConference < ActiveRecord::Migration
     add_column :conferences, :events_per_week, :text
 
     TempVersion.where(item_type: 'Event').each do |event_version|
-      event = TempEvent.find(event_version.item_id)
-      conference = TempConference.find(event.conference_id)
+      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
 
         no_events = {
@@ -64,10 +66,12 @@ class AddEventsPerWeekToConference < ActiveRecord::Migration
         end
         conference.save
         end
+      end
+    end
 
     # Cumulate the previous weeks to get a snapshot
     TempConference.all.each do |conference|
-      hash = conference.events_per_week.sort.to_hash
+      hash = conference.events_per_week.sort.to_h
       previous = nil
 
       hash.each do |week, values|