webpack.config.js

const webpack = require('webpack');
const CompressionPlugin = require('compression-webpack-plugin');

module.exports = {
    entry: "./app/main.jsx",
    output: { filename: "dist/app.js" },
    watch: true,
    plugins: [
        new webpack.DefinePlugin({
            'process.env.NODE_ENV': JSON.stringify('production')
        }),
        new webpack.optimize.ModuleConcatenationPlugin(),
        new webpack.optimize.UglifyJsPlugin({
            compress: {
                warnings: false,
                screw_ie8: false,
                conditionals: true,
                unused: true,
                comparisons: true,
                sequences: true,
                dead_code: true,
                evaluate: true,
                if_return: true,
                join_vars: true
            },
            output: {
                comments: false
            }
        }),
        new CompressionPlugin({
            asset: '[path].gz[query]',
            algorithm: 'gzip',
            test: /\.js$|\.css$|\.html$|\.eot?.+$|\.ttf?.+$|\.woff?.+$|\.svg?.+$/,
            threshold: 10240,
            minRatio: 0.8
        }),
    ],
    module: {
        loaders: [
            {
                test: /\.jsx?$/,  exclude: /node_modules/,
                loader: 'babel-loader',
                query: {
                    presets: [ 'es2015', 'stage-2', 'react' ],
                    plugins: [
                        "transform-runtime"
                    ]
                }
            }
        ]
    }
};