From c05b428d8c029d8465beb277c489e23353f8d871 Mon Sep 17 00:00:00 2001
From: Chrisbr <cbruckmayer@gmx.net>
Date: Thu, 24 Jul 2014 11:05:03 +0200
Subject: [PATCH] Assert event not deleted on add_events_per_week migration

---
 ...23203_add_events_per_week_to_conference.rb | 84 ++++++++++---------
 1 file changed, 44 insertions(+), 40 deletions(-)

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 bedf4f58..3a2f3d22 100644
--- a/db/migrate/20140701123203_add_events_per_week_to_conference.rb
+++ b/db/migrate/20140701123203_add_events_per_week_to_conference.rb
@@ -17,57 +17,61 @@ 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)
-      week = event_version.created_at.end_of_week
+      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 = {
-        new: 0,
-        withdrawn: 0,
-        unconfirmed: 0,
-        confirmed: 0,
-        canceled: 0,
-        rejected: 0,
-      }
-
-      if !conference.events_per_week
-        conference.events_per_week = {
-          week => no_events
+        no_events = {
+            new: 0,
+            withdrawn: 0,
+            unconfirmed: 0,
+            confirmed: 0,
+            canceled: 0,
+            rejected: 0,
         }
-      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
+        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
 
-        # Increment the next state
-        conference.events_per_week[week][next_state] += 1
+        if event_version.object_changes &&
+            event_version.event == 'create'
 
-        # Decrement the previous state
-        conference.events_per_week[week][prev_state] -= 1
+          # 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
       end
-      conference.save
     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|