webpack.config.js

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

const BUILD_DIR = path.resolve(__dirname, 'lib');
const APP_DIR = path.resolve(__dirname, 'src');

const WebpackConfig = {
  entry: `${APP_DIR}/index.js`,

  output: {
    path: BUILD_DIR,
    filename: 'index.js',
    libraryTarget: 'umd',
    library: 'ReactVivus',
  },

  module: {
    rules: [
      {
        loader: 'babel-loader',
        test: /\.js$/,
        exclude: /node_modules/,
        include: APP_DIR,
        options: {
          presets: ['env', 'react'],
        },
      },
    ],
  },
};

// webpack production config.
if (process.env.NODE_ENV === 'production') {
  WebpackConfig.externals = {
    react: 'react',
    'react-dom': 'react-dom',
    'prop-types': 'prop-types',
    vivus: 'vivus',
  };

  WebpackConfig.plugins = [
    new webpack.optimize.AggressiveMergingPlugin(),
    new webpack.optimize.UglifyJsPlugin({
      beautify: false,
      mangle: {
        screw_ie8: true,
      },
      compress: {
        warnings: false,
        screw_ie8: true,
      },
      comments: false,
    }),
  ];
}

module.exports = WebpackConfig;