webpack.config.js

const path = require('path');
const webpack = require('webpack');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');


const NODE_ENV = process.env.NODE_ENV || 'development';


module.exports = {
	entry: [
    'webpack-dev-server/client?http://localhost:8080',
    'webpack/hot/only-dev-server',
    'babel-polyfill', './src/main.js'],
  output: {
   	path: path.resolve(__dirname, 'public'),
		publicPath: '/',
   	filename: 'bundle.js'
	},


	devServer: {
		contentBase: __dirname + '/public',
		historyApiFallback: true,
    hot: true,
		compress: true,
    watchOptions: {
      poll: true
    }
	},

	module: {
	  rules: [
	    {
		    test: /\.(js|jsx)$/,
			  loader: "babel-loader",
			  exclude: /node_modules/,
			  options: {
		        presets: [["es2015", { "modules": false }], "stage-0", "react"],
            plugins: [
              'react-hot-loader/babel'
            ]
		      },

			},
		  {
				test: /\.(css|sass)$/, use: ['style-loader','css-loader', 'sass-loader'],
				exclude: /node_modules/,
			},
			{
				test: /\.(jpg|jpeg|gif|png)$/, use: "url-loader?mymetype=image",
				exclude: /node_modules/,
			},
      {
				test: /\.wav$/, use: "file-loader",
				exclude: /node_modules/,
			}
	  ]
  },
	plugins: [
    new webpack.HotModuleReplacementPlugin(),
	],
	node: {
			net: 'empty',
			dns: 'empty'
	}
};


if(NODE_ENV === 'production') {
    module.exports.plugins.push(
        new webpack.optimize.UglifyJsPlugin({
            compress: {
                warnings: false,
                drop_console: true,
                unsafe: true
            }
        })
    )
}