favorite user action consistency

app/models/user_action.rb

@@ -249,7 +249,29 @@ SQL
   end
 
   def self.synchronize_favorites
-    
+    exec_sql("
+    DELETE FROM user_actions ua
+    WHERE action_type = :star
+      AND NOT EXISTS (
+        SELECT 1 FROM topic_users tu
+        WHERE
+              tu.user_id = ua.user_id AND
+              tu.topic_id = ua.target_topic_id AND
+              starred
+      )", star: UserAction::STAR)
+
+    exec_sql("INSERT INTO user_actions
+             (action_type, user_id, target_topic_id, target_post_id, acting_user_id, created_at, updated_at)
+             SELECT :star, tu.user_id, tu.topic_id, -1, tu.user_id, tu.starred_at, tu.starred_at
+             FROM topic_users tu
+             WHERE starred AND NOT EXISTS(
+              SELECT 1 FROM user_actions ua
+              WHERE tu.user_id = ua.user_id AND
+                    tu.topic_id = ua.target_topic_id AND
+                    ua.action_type = :star
+             )
+             ", star: UserAction::STAR)
+
   end
 
   def self.ensure_consistency!

spec/models/user_action_spec.rb

@@ -262,18 +262,34 @@ describe UserAction do
   end
 
   describe 'synchronize_favorites' do
-    pending 'corrects out of sync favs' do
+    it 'corrects out of sync favs' do
       post = Fabricate(:post)
       post.topic.toggle_star(post.user, true)
+      UserAction.delete_all
 
       action1 = UserAction.log_action!(
         action_type: UserAction::STAR,
         user_id: post.user.id,
         acting_user_id: post.user.id,
-        target_topic_id: -1,
-        target_post_id: post.id,
+        target_topic_id: 99,
+        target_post_id: -1,
       )
 
+      action2 = UserAction.log_action!(
+        action_type: UserAction::STAR,
+        user_id: Fabricate(:user).id,
+        acting_user_id: post.user.id,
+        target_topic_id: post.topic_id,
+        target_post_id: -1,
+      )
+
+      UserAction.synchronize_favorites
+
+      actions = UserAction.all.to_a
+
+      actions.length.should == 1
+      actions.first.action_type.should == UserAction::STAR
+      actions.first.user_id.should == post.user.id
     end
   end