sS hRegisterServiceWorker(S workerURL) {
  ret hjs(replaceDollarVars(javaScript_hashLocalIdentifiers("serviceWorker_", [[
    const #check = () => {
      if (!('serviceWorker' in navigator)) {
        throw new Error('No Service Worker support!')
      }
      if (!('PushManager' in window)) {
        throw new Error('No Push API Support!')
      }
    };
    
    const #requestNotificationPermission = async () => {
      const permission = await window.Notification.requestPermission()
      // value of permission can be 'granted', 'default', 'denied'
      // granted: user has accepted the request
      // default: user has dismissed the notification permission popup by clicking on x
      // denied: user has denied the request.
      if (permission !== 'granted') {
        throw new Error('Permission not granted for Notification')
      }
    };
    
    const #registerServiceWorker = async () => {
      console.log("registerServiceWorker " + $workerURL);
      const swRegistration = await navigator.serviceWorker.register($workerURL, {scope: '/'});
      return swRegistration;
    };
    
    const #showLocalNotification = (title, body, swRegistration) => {
      swRegistration.showNotification(title, { body });
    }
    
    const #main = async () => {
      check();
      const swRegistration = await registerServiceWorker();
      console.log("Service worker registered: " + swRegistration);
      const permission = await requestNotificationPermission();
      console.log("Notification permission: " + permission);
      //showLocalNotification('Demo notification', 'Hello user', swRegistration);
    };
  
    main();
  ]]), workerURL := jsQuote(workerURL));
}