service.worker.final.js

const CACHE_NAME = "cache-<%= buildVersion %>";

const urlsToCache = ['/', '/css/main.css', '/js/main.js', <%= buildFiles %>];

self.addEventListener("install", async e => {
  self.skipWaiting();
  e.waitUntil(cacheResources());
});

const cacheResources = async () => {
  const cache = await caches.open(CACHE_NAME);
  return cache.addAll(urlsToCache);
};

self.addEventListener("activate", e => {
  e.waitUntil(clearOldCache());
});

const clearOldCache = async () => {
  const cacheNames = await caches.keys();
  const oldCacheName = cacheNames.find(name => name !== CACHE_NAME);
  caches.delete(oldCacheName);
};

self.addEventListener("fetch", e => {
  e.respondWith(getResponseByRequest(e.request));
});

const getResponseByRequest = async request => {
  const cache = await caches.open(CACHE_NAME);
  const cachedResponse = await cache.match(request);
  return cachedResponse || (await fetch(request));
};