Service Worker: Promises vs Async/Await

sw-await.js

const version = 1;
const appPrefix = 'myApp-';
const staticCacheName = appPrefix + 'static-v' + version;
const imagesCacheName = appPrefix + 'content-imgs';
var allCaches = [
  staticCacheName,
  imagesCacheName
];

self.addEventListener('message', event => {
  if (event.data.action == 'skipWaiting') {
    self.skipWaiting();
  }
});

self.addEventListener('install', event => {
  event.waitUntil(async () => {
    const cache = await caches.open(staticCacheName);
    await cache.addAll([
      '/',
      'script.js',
      'style.css'
    ]);
  }());
});

self.addEventListener('activate', event => {
  event.waitUntil(async () => {
    const keys = await caches.keys();
    const deletions = keys
      .filter(key => key.startsWith(appPrefix) && !allCaches.includes(key))
      .map(key => caches.delete(key));
    for (const success of deletions) {
      await success;
    }
  }());
});

self.addEventListener('fetch', async event => {
  let url = new URL(event.request.url);
  let response = caches.match(url) || fetch(event.request);
  event.respondWith(await response);
});

sw-promises.js

const version = 1;
const appPrefix = 'myApp-';
const staticCacheName = appPrefix + 'static-v' + version;
const imagesCacheName = appPrefix + 'content-imgs';
var allCaches = [
  staticCacheName,
  imagesCacheName
];

self.addEventListener('message', event => {
  if (event.data.action == 'skipWaiting') {
    self.skipWaiting();
  }
});

self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(staticCacheName).then(cache => {
      return cache.addAll([
        '/',
        'script.js',
        'style.css'
      ]);
    })
  );
});

self.addEventListener('activate', event => {
  event.waitUntil(
    caches.keys().then(keys => {
      return Promise.all(keys
        .filter(key => key.startsWith(appPrefix) && !allCaches.includes(key))
        .map(key => caches.delete(key))
      );
    })
  );
});

self.addEventListener('fetch', event => {
  let url = new URL(event.request.url);
  event.respondWith(
    caches.match(url).then(response => {
      return response || fetch(event.request);
    })
  );
});