js

event.waitUntil(
  clients
    .matchAll({
      type: "window",
    })
    .then((clientList) => {
      for (const client of clientList) {
        if (client.url === "/" && "focus" in client) {
          if (client.visibilityState === "hidden") return client.focus();
        }
      }
      if (clients.openWindow) {
        return clients.openWindow("/");
      }
    }),
);