sw.js

const cacheName = 'lgu';
const domain = "http://localhost/lgu";

self.addEventListener('activate', event => {
  event.waitUntil(
    (async () => {
      const keys = await caches.keys();
      return keys.map(async (cache) => {
        if(cache !== cacheName) {
          console.log('Service Worker: Removing old cache: '+ cache);
          return await caches.delete(cache);
        }
      })
    })()
  )
})

self.addEventListener('install', (event) => {
  event.waitUntil(caches.open(cacheName));
});

self.addEventListener('fetch', async (event) => {
  if (event.request.method !== "GET") return;
  if ((event.request.destination === 'image' || event.request.url.includes("/assets/") && event.request.url.includes(domain))) {
    event.respondWith(caches.open(cacheName).then((cache) => {
      return cache.match(event.request).then((cachedResponse) => {
        return cachedResponse || fetch(event.request.url).then((fetchedResponse) => {
          cache.put(event.request, fetchedResponse.clone());
          return fetchedResponse;
        });
      });
    }));
  }
  return;
});