Serviceworker for twine game

serviceworker.js

const version = 'V0.03';
const staticCacheName = version + 'staticfiles';
addEventListener('install', installEvent => {
	skipWaiting();
  installEvent.waitUntil(
    caches.open(staticCacheName)
    .then(staticCache =>{
	    // These files don't block installation
	    staticCache.addAll([
		 
	    ]); // end addAll
	    // These files must be cached for installation
	    return staticCache.addAll([
		    '/index.html',
		    '/images/image.jpg'
	    ]); // end retrun addAll
    }) // end open then
  ); // end waitUntil
}); // end addEventListener

addEventListener('activate', activateEvent => {
  activateEvent.waitUntil(
    caches.keys()
    .then( cacheNames => {
      return Promise.all(
        cacheNames.map( cacheName => {
          if (cacheName != staticCacheName) {
            return caches.delete(cacheName);
          } // end if
        }) // end map
      ); // end return Promise.all
    }) // end keys then
    .then( () => {
      return clients.claim();
    }) // end then
  ); // end waitUntil
}); // end addEventListener

addEventListener('fetch', fetchEvent => {
	// console.log('The service worker is listening.');
	const request = fetchEvent.request;
	console.log(request);
	fetchEvent.respondWith(
		// First, look in the cache
		caches.match(request)
		.then(responseFromCache =>{
			if(responseFromCache){
				return responseFromCache;
			} // end if
			// Otherwise fetch from the network
			return fetch(request)
			.catch(error =>{
				return caches.match('/index.html');
			}); // end fetch catch and return
		}) // end match then
	); // end respondWith
}); // end addEventListener