push some work out of AR callbacks into PostCreator, add a couple of helpers for post and topic creation in test

fix it so the auto_track false marks topics as new

lib/post_creator.rb

@@ -66,6 +66,7 @@ class PostCreator
       store_unique_post_key
       send_notifications_for_private_message
       track_topic
+      update_topic_stats
       update_user_counts
       publish
       @post.advance_draft_sequence
@@ -100,19 +101,6 @@ class PostCreator
     post.last_version_at ||= Time.now
   end
 
-  def self.after_create_tasks(post)
-    # Update attributes on the topic - featured users and last posted.
-    attrs = {last_posted_at: post.created_at, last_post_user_id: post.user_id}
-    attrs[:bumped_at] = post.created_at unless post.no_bump
-    post.topic.update_attributes(attrs)
-
-    # Update topic user data
-    TopicUser.change(post.user.id,
-                     post.topic.id,
-                     posted: true,
-                     last_read_post_number: post.post_number,
-                     seen_post_count: post.post_number)
-  end
 
   protected
 
@@ -184,6 +172,13 @@ class PostCreator
     @topic = topic
   end
 
+  def update_topic_stats
+    # Update attributes on the topic - featured users and last posted.
+    attrs = {last_posted_at: @post.created_at, last_post_user_id: @post.user_id}
+    attrs[:bumped_at] = @post.created_at unless @post.no_bump
+    @topic.update_attributes(attrs)
+  end
+
   def setup_post
     post = @topic.posts.new(raw: @opts[:raw],
                             user: @user,
@@ -267,6 +262,12 @@ class PostCreator
   def track_topic
     unless @opts[:auto_track] == false
       TopicUser.auto_track(@user.id, @topic.id, TopicUser.notification_reasons[:created_post])
+      # Update topic user data
+      TopicUser.change(@post.user.id,
+                       @post.topic.id,
+                       posted: true,
+                       last_read_post_number: @post.post_number,
+                       seen_post_count: @post.post_number)
     end
   end