Add unstarred_at column to topic_users so we can permanently track when topics are starred

app/models/topic.rb

@@ -569,7 +569,7 @@ class Topic < ActiveRecord::Base
   # Enable/disable the star on the topic
   def toggle_star(user, starred)
     Topic.transaction do
-      TopicUser.change(user, id, starred: starred, starred_at: starred ? DateTime.now : nil)
+      TopicUser.change(user, id, {starred: starred}.merge( starred ? {starred_at: DateTime.now, unstarred_at: nil} : {unstarred_at: DateTime.now}))
 
       # Update the star count
       exec_sql "UPDATE topics

db/migrate/20130428194335_add_unstarred_at_to_topic_users.rb

@@ -0,0 +1,5 @@
+class AddUnstarredAtToTopicUsers < ActiveRecord::Migration
+  def change
+    add_column :topic_users, :unstarred_at, :datetime
+  end
+end

spec/models/topic_spec.rb

@@ -574,15 +574,11 @@ describe Topic do
 
   describe 'toggle_star' do
 
-    before do
-      @topic = Fabricate(:topic)
-      @user = @topic.user
-    end
-
+    shared_examples_for "adding a star to a topic" do
       it 'triggers a forum topic user change with true' do
         # otherwise no chance the mock will work
         freeze_time do
-        TopicUser.expects(:change).with(@user, @topic.id, starred: true, starred_at: DateTime.now)
+          TopicUser.expects(:change).with(@user, @topic.id, starred: true, starred_at: DateTime.now, unstarred_at: nil)
           @topic.toggle_star(@user, true)
         end
       end
@@ -598,6 +594,14 @@ describe Topic do
         Topic::FavoriteLimiter.any_instance.expects(:performed!)
         @topic.toggle_star(@user, true)
       end
+    end
+
+    before do
+      @topic = Fabricate(:topic)
+      @user = @topic.user
+    end
+
+    it_should_behave_like "adding a star to a topic"
 
     describe 'removing a star' do
       before do
@@ -611,9 +615,11 @@ describe Topic do
       end
 
       it 'triggers a forum topic user change with false' do
-        TopicUser.expects(:change).with(@user, @topic.id, starred: false, starred_at: nil)
+        freeze_time do
+          TopicUser.expects(:change).with(@user, @topic.id, starred: false, unstarred_at: DateTime.now)
           @topic.toggle_star(@user, false)
         end
+      end
 
       it 'reduces the star_count' do
         lambda {
@@ -622,6 +628,13 @@ describe Topic do
         }.should change(@topic, :star_count).by(-1)
       end
 
+      describe 'and adding a star again' do
+        before do
+          @topic.toggle_star(@user, false)
+          @topic.reload
+        end
+        it_should_behave_like "adding a star to a topic"
+      end
     end
   end