PWA updater

Author: maxchistt

client/src/index.js

@@ -19,7 +19,17 @@ ReactDOM.render(
 // If you want your app to work offline and load faster, you can change
 // unregister() to register() below. Note this comes with some pitfalls.
 // Learn more about service workers: https://cra.link/PWA
-serviceWorkerRegistration.register();
+serviceWorkerRegistration.register({
+  onUpdate: updater
+});
+
+function updater(registration) {
+  alert('New version available!  Ready to update?');
+  if (registration && registration.waiting) {
+    registration.waiting.postMessage({ type: 'SKIP_WAITING' });
+  }
+  window.location.reload();
+}
 
 // If you want to start measuring performance in your app, pass a function
 // to log results (for example: reportWebVitals(console.log))