sw-precache-config.js

swPrecache.write(path.resolve(__dirname, `../public/service-worker.js`), {
  cacheId: `know-it-all`,
  filename: `service-worker.js`,
  stripPrefix: `public/`,
  staticFileGlobs: [
    `public/app.*.js`, // don't include the polyfills version
    `public/*.{html,ico,json,png}`,
  ],
  dontCacheBustUrlsMatching: [
    /\.(js|json)$/, // I'm cache busting js and json files myself
  ],
  skipWaiting: true,
}, (err) => {
  if (err) {
    reject(err);
  } else {
    resolve();
  }
});

sw-register.js

if (`serviceWorker` in navigator) {
  navigator.serviceWorker.register(`service-worker.js`);
}