webpack.config.js

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

module.exports = {
  entry: ['./src/bundle/index.js'],
  output: {
    path: path.join(process.cwd(), 'dist'),
    filename: '[name].[hash].js',
    sourceMapFilename: '[name].[hash].js.map',
    library: '@makerdao/dai',
    libraryTarget: 'umd',
  },
  resolve: {
    extensions: ['.js', '.json'],
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['env', 'stage-2'],
            // plugins: [
            //   "syntax-async-functions",
            //   "transform-regenerator"
            // ]
          },
        },
      },
      {
        test: /\.json$/,
        loader: 'json-loader',
      },
      {
        enforce: 'pre', //to check source files, not modified by other loaders (like babel-loader)
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'eslint-loader',
        options: {
          'ignorePattern': '**/*.scss'
        }
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      title: 'Maker.js demo',
      template: 'src/bundle/index.html',
      inject: 'head'
    }),
    new webpack.LoaderOptionsPlugin({
      minimize: true,
      debug: false
    }),
    new webpack.DefinePlugin({
      'process.env': {
        'NODE_ENV': JSON.stringify('production')
      }
    }),
    new UglifyJSPlugin({ uglifyOptions: {
      beautify: false,
      mangle: {
        keep_fnames: true
      },
      comments: false
    }
    })
  ],
  externals: [
    'child_process'
  ]
};

if (process.env.ANALYZE_BUNDLE) {
  const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
  module.exports.plugins.push(new BundleAnalyzerPlugin());
}