Web notification improvements

public/sw.js

@@ -0,0 +1,22 @@
+// Notification click event listener
+self.addEventListener("notificationclick", (e) => {
+  // Close the notification popout
+  e.notification.close();
+  // Get all the Window clients
+  e.waitUntil(
+    clients.matchAll({ type: "window" }).then((clientsArr) => {
+      // If a Window tab matching the targeted URL already exists, focus that;
+      const hadWindowToFocus = clientsArr.some((windowClient) =>
+        windowClient.url === e.notification.data.url
+          ? (windowClient.focus(), true)
+          : false,
+      );
+
+      // Otherwise, open a new tab to the applicable URL and focus it.
+      if (!hadWindowToFocus)
+        clients
+          .openWindow(e.notification.data.url)
+          .then((windowClient) => (windowClient ? windowClient.focus() : null));
+    }),
+  );
+});