FIX: When dismissing category inform via MessageBus (#8371)

When category is dismissed, `dismiss_new` message is sent to fronted to clean state.

In addition, I noticed that when old dismiss new button is clicked, no message is sent so I decided to kill two birds with one stone.

app/assets/javascripts/discourse/models/topic-tracking-state.js.es6

@@ -14,7 +14,8 @@ function isNew(topic) {
   return (
     topic.last_read_post_number === null &&
     ((topic.notification_level !== 0 && !topic.notification_level) ||
-      topic.notification_level >= NotificationLevels.TRACKING)
+      topic.notification_level >= NotificationLevels.TRACKING) &&
+    isUnseen(topic)
   );
 }
 
@@ -26,6 +27,10 @@ function isUnread(topic) {
   );
 }
 
+function isUnseen(topic) {
+  return !topic.is_seen;
+}
+
 const TopicTrackingState = EmberObject.extend({
   messageCount: 0,
 
@@ -68,6 +73,22 @@ const TopicTrackingState = EmberObject.extend({
         tracker.notify(data);
       }
 
+      if (data.message_type === "dismiss_new") {
+        Object.keys(tracker.states).forEach(k => {
+          const topic = tracker.states[k];
+          if (
+            !data.payload.category_id ||
+            topic.category_id === parseInt(data.payload.category_id, 0)
+          ) {
+            tracker.states[k] = Object.assign({}, topic, {
+              is_seen: true
+            });
+          }
+        });
+        tracker.notifyPropertyChange("states");
+        tracker.incrementMessageCount();
+      }
+
       if (["new_topic", "unread", "read"].includes(data.message_type)) {
         tracker.notify(data);
         const old = tracker.states["t" + data.topic_id];
@@ -215,7 +236,11 @@ const TopicTrackingState = EmberObject.extend({
 
       if (state) {
         const lastRead = t.get("last_read_post_number");
-        if (lastRead !== state.last_read_post_number) {
+        const isSeen = t.get("is_seen");
+        if (
+          lastRead !== state.last_read_post_number ||
+          isSeen !== state.is_seen
+        ) {
           const postsCount = t.get("posts_count");
           let newPosts = postsCount - state.highest_post_number,
             unread = postsCount - state.last_read_post_number;
@@ -235,7 +260,8 @@ const TopicTrackingState = EmberObject.extend({
             last_read_post_number: state.last_read_post_number,
             new_posts: newPosts,
             unread: unread,
-            unseen: !state.last_read_post_number
+            is_seen: state.is_seen,
+            unseen: !state.last_read_post_number && isUnseen(state)
           });
         }
       }

app/controllers/topics_controller.rb

@@ -849,20 +849,20 @@ class TopicsController < ApplicationController
   def reset_new
     if params[:category_id].present?
       category_ids = [params[:category_id]]
-
       if params[:include_subcategories] == 'true'
         category_ids = category_ids.concat(Category.where(parent_category_id: params[:category_id]).pluck(:id))
       end
-
       category_ids.each do |category_id|
         current_user
           .category_users
           .where(category_id: category_id)
           .first_or_initialize
           .update!(last_seen_at: Time.zone.now)
+        TopicTrackingState.publish_dismiss_new(current_user.id, category_id)
       end
     else
-      current_user.user_stat.update_column(:new_since, Time.now)
+      current_user.user_stat.update_column(:new_since, Time.zone.now)
+      TopicTrackingState.publish_dismiss_new(current_user.id)
     end
     render body: nil
   end

app/models/topic_tracking_state.rb

@@ -144,6 +144,15 @@ class TopicTrackingState
     MessageBus.publish(self.unread_channel_key(user_id), message.as_json, user_ids: [user_id])
   end
 
+  def self.publish_dismiss_new(user_id, category_id = nil)
+    payload = category_id ? { category_id: category_id } : {}
+    message = {
+      message_type: "dismiss_new",
+      payload: payload
+    }
+    MessageBus.publish(self.unread_channel_key(user_id), message.as_json, user_ids: [user_id])
+  end
+
   def self.treat_as_new_topic_clause
     User.where("GREATEST(CASE
                   WHEN COALESCE(uo.new_topic_duration_minutes, :default_duration) = :always THEN u.created_at

spec/requests/topics_controller_spec.rb

@@ -2342,6 +2342,8 @@ RSpec.describe TopicsController do
 
       user.user_stat.update_column(:new_since, old_date)
 
+      TopicTrackingState.expects(:publish_dismiss_new).with(user.id)
+
       put "/topics/reset-new.json"
       expect(response.status).to eq(200)
       user.reload
@@ -2356,6 +2358,9 @@ RSpec.describe TopicsController do
         sign_in(user)
         category_user = CategoryUser.create!(category_id: category.id, user_id: user.id)
         subcategory_user = CategoryUser.create!(category_id: subcategory.id, user_id: user.id)
+
+        TopicTrackingState.expects(:publish_dismiss_new).with(user.id, category.id.to_s)
+
         put "/topics/reset-new.json?category_id=#{category.id}"
 
         expect(category_user.reload.last_seen_at).not_to be_nil