react suspense chunck
import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';
import React, { Suspense, lazy } from 'react';
const Home = lazy(() => import('./routes/Home'));
const About = lazy(() => import('./routes/About'));
const App = () => (
<Router>
<Suspense fallback={<div>Chargement...</div>}>
<Switch>
<Route exact path="/" component={Home}/>
<Route path="/about" component={About}/>
</Switch>
</Suspense>
</Router>
);