fix(PWA): sometimes update notification is not triggered

Author: cotes2020

assets/js/pwa/app.js

@@ -3,50 +3,37 @@ layout: compress
 permalink: '/app.js'
 ---
 
-const keyWaiting = 'sw-waiting';
 const $notification = $('#notification');
 const $btnRefresh = $('#notification .toast-body>button');
 
-function skipWating(registration) {
-  registration.waiting.postMessage('SKIP_WAITING');
-  localStorage.removeItem(keyWaiting);
-}
-
 if ('serviceWorker' in navigator) {
   /* Registering Service Worker */
   navigator.serviceWorker.register('{{ "/sw.js" | relative_url }}')
     .then(registration => {
-      if (registration) {
-        registration.addEventListener('updatefound', () => {
-          let serviceWorker = registration.installing;
-
-          serviceWorker.addEventListener('statechange', () => {
-            if (serviceWorker.state === 'installed') {
-              if (navigator.serviceWorker.controller) {
-                $notification.toast('show');
-                /* in case the user ignores the notification */
-                localStorage.setItem(keyWaiting, true);
-              }
-            }
-          });
-        });
 
-        $btnRefresh.click(() => {
-          skipWating(registration);
-          $notification.toast('hide');
-        });
+      /* in case the user ignores the notification */
+      if (registration.waiting) {
+        $notification.toast('show');
+      }
 
-        if (localStorage.getItem(keyWaiting)) {
+      registration.addEventListener('updatefound', () => {
+        registration.installing.addEventListener('statechange', () => {
           if (registration.waiting) {
-            /* there's a new Service Worker waiting to be activated */
-            $notification.toast('show');
-          } else {
-            /* closed all open pages after receiving notification */
-            localStorage.removeItem(keyWaiting);
+            if (navigator.serviceWorker.controller) {
+              $notification.toast('show');
+            }
           }
+        });
+      });
+
+      $btnRefresh.click(() => {
+        if (registration.waiting) {
+          registration.waiting.postMessage('SKIP_WAITING');
         }
-      }
-    });
+        $notification.toast('hide');
+      });
+    }
+  );
 
   let refreshing = false;