webpack.config.js

const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: {
    app: ["./app/main.js"]
  },
  module: {
    loaders: [
      {
        test: /\.js$/,
        exclude: /(node_modules|bower_components)/,
        loader: 'babel-loader'
      }
    ]
  },
  output: {
    path: path.resolve(__dirname, "build"),
    publicPath: "/assets/",
    filename: "bundle.js"
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': {
        'NODE_ENV': JSON.stringify('production')
      }
    }),
    new webpack.ProvidePlugin({
      'Promise': 'es6-promise', // Thanks Aaron (https://gist.github.com/Couto/b29676dd1ab8714a818f#gistcomment-1584602)
      'fetch': 'imports?this=>global!exports?global.fetch!whatwg-fetch'
    }),
    new webpack.optimize.DedupePlugin(), //dedupe similar code 
    new webpack.optimize.UglifyJsPlugin(), //minify everything
  ],
};