[MM-17068] send mark as unread event through websocket (#12074)

app/channel.go

@@ -1802,7 +1802,17 @@ func (a *App) MarkChannelAsUnreadFromPost(postID string, userID string) (*model.
 		return nil, err
 	}
 
-	return a.Srv.Store.Channel().UpdateLastViewedAtPost(post, userID, unreadMentions)
+	channel, updateErr := a.Srv.Store.Channel().UpdateLastViewedAtPost(post, userID, unreadMentions)
+	if err != nil {
+		return channel, updateErr
+	}
+	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_UNREAD, channel.TeamId, channel.ChannelId, channel.UserId, nil)
+	message.Add("msg_count", channel.MsgCount)
+	message.Add("mention_count", channel.MentionCount)
+	message.Add("last_viewed_at", channel.LastViewedAt)
+	message.Add("post_id", postID)
+	a.Publish(message)
+	return channel, nil
 }
 
 func (a *App) esAutocompleteChannels(teamId, term string, includeDeleted bool) (*model.ChannelList, *model.AppError) {

model/websocket_message.go

@@ -14,6 +14,7 @@ const (
 	WEBSOCKET_EVENT_POSTED                  = "posted"
 	WEBSOCKET_EVENT_POST_EDITED             = "post_edited"
 	WEBSOCKET_EVENT_POST_DELETED            = "post_deleted"
+	WEBSOCKET_EVENT_POST_UNREAD             = "post_unread"
 	WEBSOCKET_EVENT_CHANNEL_CONVERTED       = "channel_converted"
 	WEBSOCKET_EVENT_CHANNEL_CREATED         = "channel_created"
 	WEBSOCKET_EVENT_CHANNEL_DELETED         = "channel_deleted"