FEATURE: Multiple notifications at once (1/topic)

app/assets/javascripts/discourse/lib/desktop-notifications.js.es6

@@ -7,7 +7,6 @@ let lastAction = -1;
 
 const focusTrackerKey = "focus-tracker";
 const idleThresholdTime = 1000 * 10; // 10 seconds
-let notificationTagName; // "discourse-notification-popup-" + Discourse.SiteSettings.title;
 
 // Called from an initializer
 function init(messageBus) {
@@ -25,8 +24,6 @@ function init(messageBus) {
     return;
   }
 
-
-
   if (!("Notification" in window)) {
     Em.Logger.info('Discourse desktop notifications are disabled - not supported by browser');
     return;
@@ -55,8 +52,6 @@ function init(messageBus) {
 // This function is only called if permission was granted
 function setupNotifications() {
 
-  notificationTagName = "discourse-notification-popup-" + Discourse.SiteSettings.title;
-
   window.addEventListener("storage", function(e) {
     // note: This event only fires when other tabs setItem()
     const key = e.key;
@@ -108,13 +103,14 @@ function onNotification(data) {
 
   const notificationBody = data.excerpt;
   const notificationIcon = Discourse.SiteSettings.logo_small_url || Discourse.SiteSettings.logo_url;
+  const notificationTag = "discourse-notification-" + Discourse.SiteSettings.title + "-" + data.topic_id;
 
   requestPermission().then(function() {
     // This shows the notification!
     const notification = new Notification(notificationTitle, {
       body: notificationBody,
       icon: notificationIcon,
-      tag: notificationTagName
+      tag: notificationTag
     });
 
     function clickEventHandler() {

app/services/post_alerter.rb

@@ -157,6 +157,7 @@ class PostAlerter
           notification_type: type,
           post_number: original_post.post_number,
           topic_title: original_post.topic.title,
+          topic_id: original_post.topic.id,
           excerpt: original_post.excerpt(400, text_entities: true, strip_links: true),
           username: original_username,
           post_url: post_url