FIX: Correct highest post number for read topic tracking state. (#14273)

spec/models/topic_tracking_state_spec.rb

@@ -40,6 +40,43 @@ describe TopicTrackingState do
     end
   end
 
+  describe '.publish_read' do
+    it 'correctly publish read' do
+      message = MessageBus.track_publish(described_class.unread_channel_key(post.user.id)) do
+        TopicTrackingState.publish_read(post.topic_id, 1, post.user)
+      end.first
+
+      data = message.data
+
+      expect(message.user_ids).to contain_exactly(post.user_id)
+      expect(message.group_ids).to eq(nil)
+      expect(data["topic_id"]).to eq(post.topic_id)
+      expect(data["message_type"]).to eq(described_class::READ_MESSAGE_TYPE)
+      expect(data["payload"]["last_read_post_number"]).to eq(1)
+      expect(data["payload"]["highest_post_number"]).to eq(1)
+      expect(data["payload"]["notification_level"]).to eq(nil)
+    end
+
+    it 'correctly publish read for staff' do
+      create_post(
+        raw: "this is a test post",
+        topic: post.topic,
+        post_type: Post.types[:whisper],
+        user: Fabricate(:admin)
+      )
+
+      post.user.grant_admin!
+
+      message = MessageBus.track_publish(described_class.unread_channel_key(post.user.id)) do
+        TopicTrackingState.publish_read(post.topic_id, 1, post.user)
+      end.first
+
+      data = message.data
+
+      expect(data["payload"]["highest_post_number"]).to eq(2)
+    end
+  end
+
   describe '#publish_unread' do
     it "can correctly publish unread" do
       message = MessageBus.track_publish(described_class.unread_channel_key(post.user.id)) do