Progressive Web Apps with React

Logging out the result

Lastly, let's add some console.logs so that we know the result of the registration. Luckily, navigator.serviceWorker.register returns a promise:

<script>  if ('serviceWorker' in navigator) {    window.addEventListener('load', function() {      navigator.serviceWorker.register('sw.js').then(function(registration) {        // Registration was successful        console.log('Registered!');      }, function(err) {        // registration failed :(        console.log('ServiceWorker registration failed: ', err);      }).catch(function(err) {        console.log(err);      });    });  } else {    console.log('service worker is not supported');  }</script>

Okay, let's test this all out! Reload the page, and if all is good, you should see the following in your console:

You can also check it ...