'use strict'; if ('serviceWorker' in navigator) { navigator.serviceWorker .register('/serviceworker.js', { scope: '/' }) .then(function swStart(registration) { // registered! }) .catch(error => { // eslint-disable-next-line no-console console.log('ServiceWorker registration failed: ', error); }); } window.addEventListener('beforeinstallprompt', e => { // beforeinstallprompt Event fired // e.userChoice will return a Promise. e.userChoice.then(choiceResult => { ga('send', 'event', 'PWA-install', choiceResult.outcome); }); });