Improve MessageBus.track_publish to allow filter by channel.

spec/components/post_merger_spec.rb

@@ -15,9 +15,8 @@ describe PostMerger do
       reply3 = create_post(topic: topic, raw: 'The third reply', post_number: 4, user: user)
       replies = [reply3, reply2, reply1]
 
-      message = MessageBus.track_publish { PostMerger.new(admin, replies).merge }.last
+      message = MessageBus.track_publish("/topic/#{topic.id}") { PostMerger.new(admin, replies).merge }.last
 
-      expect(message.channel).to eq("/topic/#{topic.id}")
       expect(message.data[:type]).to eq(:revised)
       expect(message.data[:post_number]).to eq(reply3.post_number)
 

spec/components/post_revisor_spec.rb

@@ -382,11 +382,10 @@ describe PostRevisor do
       it "should publish topic changes to clients" do
         revisor = described_class.new(topic.ordered_posts.first, topic)
 
-        messages = MessageBus.track_publish do
+        message = MessageBus.track_publish("/topic/#{topic.id}") do
           revisor.revise!(newuser, title: 'this is a test topic')
-        end
+        end.first
 
-        message = messages.find { |m| m.channel == "/topic/#{topic.id}" }
         payload = message.data
         expect(payload[:reload_topic]).to eq(true)
       end

spec/components/site_setting_extension_spec.rb

@@ -145,11 +145,11 @@ describe SiteSettingExtension do
         settings.setting("test_setting", 100)
         settings.setting("test_setting", nil, client: true)
 
-        messages = MessageBus.track_publish do
+        message = MessageBus.track_publish('/client_settings') do
           settings.test_setting = 88
-        end
+        end.first
 
-        expect(messages.map(&:channel).include?('/client_settings')).to eq(true)
+        expect(message).to be_present
       end
     end
   end