Code splitting with React.lazy, Suspense and react-router-dom doesn't work

Question

I am trying to set up a very basic example, similar to: https://reactjs.org/docs/code-splitting.html#route-based-code-splitting

It should lazy-load route component (ModuleOne or ModuleTwo) with their dependencies dynamically depending on current route.

However looks like code-splitting doesn't work and everything is included in one bundle.

webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  entry: './src/index',
  output: {
    filename: '[name].bundle.js',
    chunkFilename: '[name].bundle.js',
    path: path.resolve(__dirname, '../dist'),
  },
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        loader: 'awesome-typescript-loader',
        exclude: /node_modules/,
      }
    ],
  },
  resolve: {
    modules: ['node_modules', path.resolve(__dirname, '../src')],
    extensions: ['.js', '.jsx', '.ts', '.tsx'],
  }
};

App.tsx

import * as React from 'react';
import { HashRouter as Router, Link, Route, Switch } from 'react-router-dom';
import * as styles from './App.scss';

const LazyModuleOne = React.lazy(() => import('../modules/ModuleOne/ModuleOne'));
const LazyModuleTwo = React.lazy(() => import('../modules/ModuleTwo/ModuleTwo'));

const App = () => (
    <Router>
        <div className={styles.wrapper}>
            <nav>
                <Link to="/">Start</Link>
                <Link to="/module-one">Module One</Link>
                <Link to="/module-two">Module Two</Link>
            </nav>
            <main>
                <React.Suspense fallback={<div>Loading...</div>}>
                    <Switch>
                        <Route path="/module-one" component={LazyModuleOne} />
                        <Route path="/module-two" component={LazyModuleTwo} />
                    </Switch>
                </React.Suspense>
            </main>
        </div>
    </Router>
);

export default App;

ModuleOne.tsx

import * as React from 'react';
import * as _ from 'lodash';
import { RouteComponentProps } from 'react-router';

const apples = _.fill([1,2,3], 'apple');

const ModuleOne: React.FC<RouteComponentProps> = () => (
  <div>
    <div>ModuleOne</div>
    <div>There are {apples.length} apples</div>
  </div>
)

export default ModuleOne;

ModuleTwo.tsx

import * as React from 'react';
import * as R from 'ramda';
import { RouteComponentProps } from 'react-router';

const cherries = [1,2,3];

const ModuleTwo: React.SFC<RouteComponentProps> = () => (
  <div>
    <div>ModuleTwo</div>
    <div>There are {R.length(cherries)} cherries</div>
  </div>
)

export default ModuleTwo;

Demo:

Does anyone have an idea why Route-based code-splitting doesn't work as expected?

Answer 1

I found the solution. It's TypeScript-related. I needed to set:

{
  "compilerOptions": {
    "module": "esnext",
  },
}

instead of commonjs.

Now code-splitting works as expected.