webpack.config.js

var webpack = require('webpack');
var plugins = [];

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

module.exports = {
  entry: './index.js',
  output: {
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'babel',
        query: {
          presets: ['es2015', 'react']
        }
      },
      {
        test: /\.png$/,
        loader: 'file'
      },
      {
        test: /\.scss$/,
        loaders: ['style', 'css', 'sass']
      },
      {
        test: /\/api\//,
        loader: 'json-loader'
      }
    ]
  },
  resolve: {
    modulesDirectories: [ 'app', 'node_modules' ]
  },
  devServer: {
    historyApiFallback: true
  },
  plugins: plugins
};