webpack.config.dev.babel.js

import webpack from 'webpack';
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
import path from 'path';

/**
 * Development webpack config designed to be loaded by express development server
 */

module.exports = {
    /**
     * The scripts in entry are combined in order to create our bundle
     */
    mode: 'development',
    entry: [
        'babel-regenerator-runtime',
        path.resolve(__dirname, 'src')
    ],
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'bundle.js',
        publicPath: '/'
    },
    optimization: {
        minimizer: [
            // we specify a custom UglifyJsPlugin here to get source maps in production
            new UglifyJsPlugin({
                cache: true,
                parallel: true,
                uglifyOptions: {
                    compress: false,
                    ecma: 6,
                    mangle: true
                },
                sourceMap: true
            })
        ]
    },
    plugins: [
        new webpack.DefinePlugin({
            'process.env': {
                NODE_ENV: JSON.stringify('production'),
                WEBPACK: true
            }
        }),
        /*
        * Uglifies JS which improves performance
        * React will throw console warnings if this is not implemented
        */
    ],
    resolve: {
        extensions: ['.js', '.json', '.jsx'],
    },
    module: {
        rules: [
            {
                test: /.jsx?$/,
                use: {
                    loader: 'babel-loader'
                },
                include: path.resolve(__dirname, 'src')
            }
        ]
    }
};