webpack.config.js

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

var config = {
    entry: './app/App.js',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'index_bundle.js',
        publicPath: '/'
    },
    module: {
        rules: [
          { test: /\.(js)$/, use: 'babel-loader' },
          { test: /\.css$/, use: [ 'style-loader' , 'css-loader'] }
        ]
    },
    devServer: {
        historyApiFallback: true
    },
    plugins : [new HtmlWebpackPlugin({
        template: 'app/index.html'
    })]
};

if (process.env.NODE_ENV === 'production') {
    config.plugins.push(
        new webpack.DefinePlugin({
            'process.env' : {
                'NODE_ENV': JSON.stringify(process.env.NODE_ENV)
            }
        }),
        new webpack.optimize.UglifyJsPlugin()
    )
}

module.exports = config;