worker.js

'use strict';

self.addEventListener('install', event => {
  // The skipWaiting() method allows this service worker to progress from the registration's
  // waiting position to active even while service worker clients are using the registration.
  // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#service-worker-global-scope-skipwaiting
  event.waitUntil(self.skipWaiting());
});

self.addEventListener('activate', event => {
  // The claim() method of the of the Clients interface allows an active Service Worker to set
  // itself as the active worker for a client page when the worker and the page are in the same
  // scope. This triggers an oncontrollerchange event on any client pages within the Service
  // Worker's scope.
  // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#clients-claim-method
  event.waitUntil(self.clients.claim());
});

self.importScripts('main.js');