DEV: MessageBus last_id from server side

Author: keegangeorge

assets/javascripts/discourse/components/ai-post-helper-menu.gjs

@@ -43,6 +43,8 @@ export default class AiPostHelperMenu extends Component {
   @tracked lastSelectedOption = null;
   @tracked isSavingFootnote = false;
   @tracked supportsAddFootnote = this.args.data.supportsFastEdit;
+  @tracked channel =
+    `/discourse-ai/ai-helper/stream_suggestion/${this.args.data.quoteState.postId}`;
 
   @tracked
   smoothStreamer = new SmoothStreamer(
@@ -150,27 +152,26 @@ export default class AiPostHelperMenu extends Component {
 
   @bind
   subscribe() {
-    const channel = `/discourse-ai/ai-helper/stream_suggestion/${this.args.data.quoteState.postId}`;
     this.messageBus.subscribe(
-      channel,
+      this.channel,
       (data, id) => {
-        this._lastMessageIds[channel] = id;
+        this._lastMessageIds[this.channel] =
+          this.args.data.post.discourse_ai_helper_stream_suggestion_last_message_bus_id;
         this._updateResult(data, id);
       },
-      this._lastMessageIds[channel]
+      this._lastMessageIds[this.channel]
     );
   }
 
   @bind
   unsubscribe() {
-    this.messageBus.unsubscribe(
-      "/discourse-ai/ai-helper/stream_suggestion/*",
-      this._updateResult
-    );
+    this.messageBus.unsubscribe(this.channel, this._updateResult);
   }
 
   @bind
   async _updateResult(result) {
+    this._lastMessageIds[this.channel] =
+      this.args.data.post.discourse_ai_helper_stream_suggestion_last_message_bus_id;
     this.streaming = !result.done;
     await this.smoothStreamer.updateResult(result, "result");
   }

lib/ai_helper/entry_point.rb

@@ -73,6 +73,12 @@ def inject_into(plugin)
               scope.user.in_any_groups?(SiteSetting.ai_auto_image_caption_allowed_groups_map)
           end,
         ) { object.auto_image_caption }
+
+        plugin.add_to_serializer(
+          :post,
+          :discourse_ai_helper_stream_suggestion_last_message_bus_id,
+          include_condition: -> { SiteSetting.ai_helper_enabled && scope.authenticated? },
+        ) { MessageBus.last_id("/discourse-ai/ai-helper/stream_suggestion/#{object.id}") }
       end
     end
   end

spec/system/ai_helper/ai_post_helper_spec.rb

@@ -107,13 +107,6 @@ def select_post_text(selected_post)
 
         DiscourseAi::Completions::Llm.with_prepared_responses([explain_response]) do
           post_ai_helper.select_helper_model(mode)
-
-          MessageBus.publish(
-            "/discourse-ai/ai-helper/stream_suggestion/#{post.id}",
-            { result: explain_response, done: true },
-            user_ids: [user.id],
-          )
-
           wait_for { post_ai_helper.has_suggestion_value? }
           expect(post_ai_helper.suggestion_value).to eq(explain_response)
         end