webpack.config.js

const dev = process.env.NODE_ENV !== 'production';
const webpack = require('webpack');
const path = require('path');
const {BundleAnalyzerPlugin} = require('webpack-bundle-analyzer');
const FriendlyErrorsWebpackPlugin = require('friendly-errors-webpack-plugin');

const plugins = [
	new FriendlyErrorsWebpackPlugin(),
];

if (!dev) {
	plugins.push(
		new webpack.optimize.OccurrenceOrderPlugin(),
			new BundleAnalyzerPlugin({
			analyzerMode: 'static',
			reportFilename: 'webpack-report.html',
			openAnalyzer: false,
		})
	);
}

module.exports = {
	mode: dev ? 'development' : 'production',
	context: path.join(__dirname, 'src'),
	devtool: dev ? 'none' : 'source-map',
	entry: {
		app: './js/App.jsx',
		lib: [
			'react', 
			'react-dom'
		]
	},

	resolve: {
		extensions: ['.js', '.jsx', '.es6']
	},

	module: {
		rules: [
			{
				test: /\.jsx?$/,
				exclude: /(node_modules|bower_components)/,
				loader: 'babel-loader'
			},

			{
				test: /\.css$/,
				exclude: /node_modules/,
				use: [
					'style-loader',
					{
						loader: 'css-loader',
						options: {
							modules: true
						}
					}
				]
			}
		]
	},

	output: {
		path: path.resolve(__dirname, 'dist'),
		filename: 'js/[name].bundle.js'
	},

	optimization: {
		splitChunks: {
			cacheGroups: {
				commons: {
					chunks: 'initial',
					minChunks: Infinity,
					name: 'lib',
					enforce: true
				}
			}
		}
	},

	plugins
};