feat: increment cache version and add notification click handler to focus or open app window

Author: kstgrd

sw.js

@@ -1,4 +1,4 @@
-const CACHE_NAME = 'pomodoro-v8';
+const CACHE_NAME = 'pomodoro-v9';
 const ASSETS = [
   './',
   './index.html',
@@ -32,6 +32,18 @@ self.addEventListener('message', e => {
   }
 });
 
+self.addEventListener('notificationclick', e => {
+  e.notification.close();
+  e.waitUntil(
+    self.clients.matchAll({ type: 'window', includeUncontrolled: true }).then(clients => {
+      if (clients.length) {
+        return clients[0].focus();
+      }
+      return self.clients.openWindow('./');
+    })
+  );
+});
+
 self.addEventListener('fetch', e => {
   if (e.request.method !== 'GET') return;
   if (!e.request.url.startsWith(self.location.origin)) return;