FIX: Background like count update didn't account for own user actions (#16688)

This fixes a corner case of the perf optimization in d4e35f5.

When you have the the same post showing in multiple tab/devices and like
said post in one place, we updated the like count but didn't flip the
`acted` bool in the front-end. This caused a small visual desync.

Co-authored-by: Penar Musaraj <pmusaraj@gmail.com>

app/assets/javascripts/discourse/app/controllers/topic.js

@@ -1712,9 +1712,15 @@ export default Controller.extend(bufferedProperty("model"), {
               .then(() => refresh({ id: data.id, refreshLikes: true }));
             break;
           }
-          case "liked": {
+          case "liked":
+          case "unliked": {
             postStream
-              .triggerLikedPost(data.id, data.likes_count)
+              .triggerLikedPost(
+                data.id,
+                data.likes_count,
+                data.user_id,
+                data.type
+              )
               .then(() => refresh({ id: data.id, refreshLikes: true }));
             break;
           }

app/assets/javascripts/discourse/app/models/post-stream.js

@@ -847,12 +847,12 @@ export default RestModel.extend({
     return resolved;
   },
 
-  triggerLikedPost(postId, likesCount) {
+  triggerLikedPost(postId, likesCount, userID, eventType) {
     const resolved = Promise.resolve();
 
     const post = this.findLoadedPost(postId);
     if (post) {
-      post.updateLikeCount(likesCount);
+      post.updateLikeCount(likesCount, userID, eventType);
       this.storePost(post);
     }
 

app/assets/javascripts/discourse/app/models/post.js

@@ -355,21 +355,18 @@ const Post = RestModel.extend({
     }
   },
 
-  updateLikeCount(count) {
+  updateLikeCount(count, userId, eventType) {
+    let ownLike = User.current()?.id === userId && eventType === "liked";
     let current_actions_summary = this.get("actions_summary");
     let likeActionID = Site.current().post_action_types.find(
       (a) => a.name_key === "like"
     ).id;
+    const newActionObject = { id: likeActionID, count, acted: ownLike };
 
     if (!this.actions_summary.find((entry) => entry.id === likeActionID)) {
       let json = Post.munge({
         id: this.id,
-        actions_summary: [
-          {
-            id: likeActionID,
-            count,
-          },
-        ],
+        actions_summary: [newActionObject],
       });
       this.set(
         "actions_summary",
@@ -378,11 +375,12 @@ const Post = RestModel.extend({
       this.set("actionByName", json.actionByName);
       this.set("likeAction", json.likeAction);
     } else {
-      this.actions_summary.find(
-        (entry) => entry.id === likeActionID
-      ).count = count;
-      this.actionByName["like"] = count;
-      this.likeAction.count = count;
+      Object.assign(
+        this.actions_summary.find((entry) => entry.id === likeActionID),
+        newActionObject
+      );
+      Object.assign(this.actionByName["like"], newActionObject);
+      Object.assign(this.likeAction, newActionObject);
     }
   },
 

lib/post_action_creator.rb

@@ -161,7 +161,7 @@ private
 
   def notify_subscribers
     if @post_action_name == :like
-      @post.publish_change_to_clients! :liked, { likes_count: @post.like_count + 1 }
+      @post.publish_change_to_clients! :liked, { likes_count: @post.like_count + 1, user_id: @created_by.id }
     elsif self.class.notify_types.include?(@post_action_name)
       @post.publish_change_to_clients! :acted
     end

lib/post_action_destroyer.rb

@@ -65,7 +65,7 @@ protected
   def notify_subscribers
     name = PostActionType.types[@post_action_type_id]
     if name == :like
-      @post.publish_change_to_clients!(:liked, { likes_count: @post.like_count })
+      @post.publish_change_to_clients!(:unliked, { likes_count: @post.like_count, user_id: @destroyed_by.id })
     elsif self.class.notify_types.include?(name)
       @post.publish_change_to_clients!(:acted)
     end

spec/lib/post_action_creator_spec.rb

@@ -60,6 +60,19 @@ describe PostActionCreator do
       expect(result.post_action.post_action_type_id).to eq(like_type_id)
     end
 
+    it 'notifies subscribers' do
+      expect(post.reload.like_count).to eq(0)
+
+      messages = MessageBus.track_publish do
+        PostActionCreator.new(user, post, like_type_id).perform
+      end
+
+      message = messages.last.data
+      expect(message[:type]).to eq(:liked)
+      expect(message[:likes_count]).to eq(1)
+      expect(message[:user_id]).to eq(user.id)
+    end
+
     it 'does not create an invalid post action' do
       result = PostActionCreator.new(user, nil, like_type_id).perform
       expect(result.failed?).to eq(true)

spec/lib/post_action_destroyer_spec.rb

@@ -26,8 +26,9 @@ describe PostActionDestroyer do
           end
 
           message = messages.last.data
-          expect(message[:type]).to eq(:liked)
+          expect(message[:type]).to eq(:unliked)
           expect(message[:likes_count]).to eq(0)
+          expect(message[:user_id]).to eq(user.id)
         end
       end