app-shell-sw.js

const staticCacheName = 'app-shell-static-v1';

const staticCacheFileNames = [
  'public/offline.html',
  'lib/app.js'
];

self.addEventListener('install', (event) => {
  self.skipWaiting();
  event.waitUntil(
    caches.open(staticCacheName)
    .then((cache) => {
      cache.addAll([
        '/',
        'manifest.json',
        ...staticCacheFileNames
      ]);
    })
    .catch((error) => {
      console.log(`Error caching static assets: ${error}`);
    })
  );
});

self.addEventListener('activate', (event) => {
  if (self.clients && clients.claim) {
    clients.claim();
  }
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.filter((cacheName) => {
          return cacheName.startsWith('app-shell-') && cacheName !== staticCacheName;
        })
        .map((cacheName) => {
          return caches.delete(cacheName);
        })
      ).catch((error) => {
        console.log(`Some error occurred while removing existing cache: ${error}`);
      });
    }).catch((error) => {
      console.log(`Some error occurred while removing existing cache: ${error}`);
    }));
});

self.addEventListener('fetch', (event) => {
  event.respondWith(
    caches.match(event.request).then((response) => {
      return response || fetch(event.request)
    }).catch((error) => {
      console.log(`Some error occurred while saving data to dynamic cache: ${error}`);
    })
  );
});