sw.js

importScripts('https://storage.googleapis.com/workbox-cdn/releases/6.4.1/workbox-sw.js');

const { googleAnalytics } = workbox;
const { ExpirationPlugin } = workbox.expiration;
const { registerRoute } = workbox.routing;
const { CacheFirst, StaleWhileRevalidate } = workbox.strategies;

registerRoute(
  ({ request }) => request.destination === 'image',
  new StaleWhileRevalidate({ cacheName: 'images'  }),
);

registerRoute(
  ({ request }) => request.destination === 'style',
  new StaleWhileRevalidate({
    cacheName: 'styles',
    plugins: [
      new ExpirationPlugin({
        maxAgeSeconds: 60 * 60 * 24 * 30, // 14 Days
      }),
    ],
  }),
);

registerRoute(
  ({ request }) => request.destination === 'script',
  new StaleWhileRevalidate({
    cacheName: 'scripts',
    plugins: [
      new ExpirationPlugin({
        maxAgeSeconds: 60 * 60 * 24 * 30, // 14 Days
      }),
    ],
  }),
);

registerRoute(
  ({ request }) => request.destination === 'font',
  new CacheFirst({
    cacheName: 'fonts',
    plugins: [
      new ExpirationPlugin({
        maxAgeSeconds: 60 * 60 * 24 * 365, // 365 Days
      }),
    ],
  }),
);

// Offline Google Analytics
googleAnalytics.initialize();