index.js

import { ServiceWorkerProvider, useServiceWorker } from './useServiceWorker';

const App = () => {
  const { isUpdateAvailable, updateAssets } = useServiceWorker();
  
  return (
    <div>
      Hello, World!
      
      {isUpdateAvailable && (
        <div>
          A new version of this app is available!
          <button type="button" onClick={updateAssets}>Update now</button>
        </div>
      )}
  );
}

ReactDOM.render(
  <ServiceWorkerProvider>
    <App />
  </ServiceWorkerProvider>,
  document.querySelector('#root')
);