Move MessageBus observer into PostCreator

app/models/message_bus_observer.rb

@@ -3,15 +3,7 @@ require_dependency 'discourse_observer'
 # This class is responsible for notifying the message bus of various
 # events.
 class MessageBusObserver < DiscourseObserver
-  observe :post, :notification, :user_action, :topic
-
-  def after_create_post(post)
-    MessageBus.publish("/topic/#{post.topic_id}",
-                        id: post.id,
-                        created_at: post.created_at,
-                        user: BasicUserSerializer.new(post.user).as_json(root: false),
-                        post_number: post.post_number)
-  end
+  observe :notification, :user_action, :topic
 
   def after_create_notification(notification)
     refresh_notification_count(notification)

lib/post_creator.rb

@@ -110,6 +110,13 @@ class PostCreator
 
       # Update `last_posted_at` to match the post's created_at
       @user.update_column(:last_posted_at, post.created_at)
+
+      # Publish the post in the message bus
+      MessageBus.publish("/topic/#{post.topic_id}",
+                    id: post.id,
+                    created_at: post.created_at,
+                    user: BasicUserSerializer.new(post.user).as_json(root: false),
+                    post_number: post.post_number)
     end
 
     post

spec/components/post_creator_spec.rb

@@ -11,6 +11,7 @@ describe PostCreator do
 
   context 'new topic' do
     let(:category) { Fabricate(:category, user: user) }
+    let(:topic) { Fabricate(:topic, user: user) }
     let(:basic_topic_params) { {title: 'hello world topic', raw: 'my name is fred', archetype_id: 1} }
     let(:image_sizes) { {'http://an.image.host/image.jpg' => {'width' => 111, 'height' => 222}} }
 
@@ -38,6 +39,12 @@ describe PostCreator do
         creator.create
       end
 
+      it 'enqueues the post on the message bus' do
+        MessageBus.stubs(:publish).with("/users/#{user.username}", anything)
+        MessageBus.expects(:publish).with("/topic/#{topic.id}", instance_of(Hash))
+        PostCreator.new(user, raw: basic_topic_params[:raw], topic_id: topic.id)
+      end
+
       it 'features topic users' do
         Jobs.stubs(:enqueue).with(:process_post, anything)
         Jobs.expects(:enqueue).with(:feature_topic_users, has_key(:topic_id))

spec/models/post_spec.rb

@@ -81,14 +81,6 @@ describe Post do
     end
   end
 
-  describe 'message bus' do
-    it 'enqueues the post on the message bus' do
-      topic = self.topic
-      MessageBus.expects(:publish).with("/topic/#{topic.id}", instance_of(Hash))
-      Fabricate(:post, post_args)
-    end
-  end
-
   describe "maximum images" do
     let(:post_no_images) { Fabricate.build(:post, post_args) }
     let(:post_one_image) { Fabricate.build(:post, post_args.merge(raw: "![sherlock](http://bbc.co.uk/sherlock.jpg)")) }