add lazy

src/router.js

@@ -1,20 +1,25 @@
-import React from "react";
+import React, { lazy, Suspense } from "react";
 import { Switch, Route } from "react-router-dom";
-import App from "./container/App";
-import FetchPage from "./container/fetchPage";
+// import App from "./container/App";
+// import FetchPage from "./container/fetchPage";
 import Auth from "./container/Auth";
 
 import Header from "./components/header";
 
 import PrivateRoute from "./privateRouter";
 
+const app = lazy(() => import("./container/Auth"));
+const FetchPage = lazy(() => import("./container/fetchPage"));
+
 export default () => (
 	<div className="container">
-		<Header />
-		<Switch>
-			<PrivateRoute path="/" exact component={App} />
-			<Route path="/auth" render={props => <Auth name="Tony" {...props} />} />
-			<Route exact path="/fetch" component={FetchPage} />
-		</Switch>
+		<Suspense fallback={<div>Loading...</div>}>
+			<Header />
+			<Switch>
+				<PrivateRoute path="/" exact component={app} />
+				<Route path="/auth" render={props => <Auth name="Tony" {...props} />} />
+				<Route exact path="/fetch" component={FetchPage} />
+			</Switch>
+		</Suspense>
 	</div>
 );