How to build js modules (webpack)?

Question

JavaScript

Hello.
index.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './containers/app';

ReactDOM.render(
    <App/>,
    document.getElementById('app')
);

When you call the webpack command, everything compiles perfectly into 1 build.js file, runs in the browser and works.
But he wants it to be something like this:

import React from 'react';
import ReactDOM from 'react-dom';

const App = requery('app');

ReactDOM.render(
    <App/>,
    document.getElementById('app')
);

And also, when compiling, get two files build.js, app.js and when loading build.js into the browser, app.js was automatically pulled up.
Please, tell me how this can be implemented?
Thank you!

Answer 1

https://webpack.github.io/docs/code-splitting.html
This code will not work directly, because automatically downloading an additional file is an asynchronous action.