don't unresolve links in quiz data when shifting dates

test plan:
* create a quiz with a question with a link to a file
 (or anything, really)
* copy the course with date shifting
* the link should work when taking the quiz as a student

closes #CNVS-22615

Change-Id: I5eaf1026d74473e14ffbcbd166b71b245cc2f731
Reviewed-on: https://gerrit.instructure.com/62360
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Jenkins
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>

app/models/importers/course_content_importer.rb

@@ -157,6 +157,7 @@ module Importers
           shift_options = self.shift_date_options(course, shift_options)
 
           migration.imported_migration_items_by_class(Assignment).each do |event|
+            event.reload # just in case
             event.due_at = shift_date(event.due_at, shift_options)
             event.lock_at = shift_date(event.lock_at, shift_options)
             event.unlock_at = shift_date(event.unlock_at, shift_options)
@@ -165,6 +166,7 @@ module Importers
           end
 
           migration.imported_migration_items_by_class(Announcement).each do |event|
+            event.reload
             event.delayed_post_at = shift_date(event.delayed_post_at, shift_options)
             event.save_without_broadcasting
           end
@@ -176,18 +178,21 @@ module Importers
           end
 
           migration.imported_migration_items_by_class(DiscussionTopic).each do |event|
+            event.reload
             event.delayed_post_at = shift_date(event.delayed_post_at, shift_options)
             event.lock_at = shift_date(event.lock_at, shift_options)
             event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(CalendarEvent).each do |event|
+            event.reload
             event.start_at = shift_date(event.start_at, shift_options)
             event.end_at = shift_date(event.end_at, shift_options)
             event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(Quizzes::Quiz).each do |event|
+            event.reload # have to reload the quiz_data to keep link resolution - the others are just in case
             event.due_at = shift_date(event.due_at, shift_options)
             event.lock_at = shift_date(event.lock_at, shift_options)
             event.unlock_at = shift_date(event.unlock_at, shift_options)

db/migrate/20150902140556_fix_unresolved_links_in_quizzes.rb

@@ -0,0 +1,10 @@
+class FixUnresolvedLinksInQuizzes < ActiveRecord::Migration
+  tag :postdeploy
+  def up
+    DataFixup::FixUnresolvedLinksInQuizzes.send_later_if_production_enqueue_args(:run,
+      :priority => Delayed::LOW_PRIORITY, :n_strand => 'long_datafixups')
+  end
+
+  def down
+  end
+end

lib/data_fixup/fix_unresolved_links_in_quizzes.rb

@@ -0,0 +1,12 @@
+module DataFixup
+  module FixUnresolvedLinksInQuizzes
+    def self.run
+      Quizzes::Quiz.find_ids_in_ranges(:batch_size => 10000) do |min_id, max_id|
+        Quizzes::Quiz.where(id: min_id..max_id).where("quiz_data like ?", "%LINK.PLACEHOLDER%").find_each do |quiz|
+          quiz.generate_quiz_data
+          quiz.save
+        end
+      end
+    end
+  end
+end

spec/models/content_migration/course_copy_dates_spec.rb

@@ -382,5 +382,41 @@ describe ContentMigration do
       expect(@copy_to.start_at).to eq start_at
       expect(@copy_to.conclude_at).to eq conclude_at
     end
+
+    it "should not break link resolution in quiz_data" do
+      topic = @copy_from.discussion_topics.create!(:title => "some topic", :message => "<p>some text</p>")
+
+      html = "<a href='/courses/#{@copy_from.id}/discussion_topics/#{topic.id}'>link</a>"
+
+      bank = @copy_from.assessment_question_banks.create!(:title => 'bank')
+      data = {'question_name' => 'test question', 'question_type' => 'essay_question', 'question_text' => html}
+      aq = bank.assessment_questions.create!(:question_data => data)
+
+      quiz = @copy_from.quizzes.create!(:due_at => "05 Jul 2012 06:00:00 UTC +00:00")
+      qq = quiz.quiz_questions.create!(:question_data => data)
+      quiz.generate_quiz_data
+      quiz.published_at = Time.now
+      quiz.workflow_state = 'available'
+      quiz.save!
+
+      options = {
+        :everything => true,
+        :shift_dates => true,
+        :old_start_date => 'Jul 1, 2012',
+        :old_end_date => 'Jul 11, 2012',
+        :new_start_date => 'Aug 5, 2012',
+        :new_end_date => 'Aug 15, 2012'
+      }
+      @cm.copy_options = options
+      @cm.save!
+
+      run_course_copy
+
+      topic_to = @copy_to.discussion_topics.where(:migration_id => mig_id(topic)).first
+      quiz_to = @copy_to.quizzes.where(:migration_id => mig_id(quiz)).first
+      data = quiz_to.quiz_data.to_yaml
+      expect(data).to_not include("LINK.PLACEHOLDER")
+      expect(data).to include("courses/#{@copy_to.id}/discussion_topics/#{topic_to.id}")
+    end
   end
 end