webpack.config.js

const path = require('path')
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
const TerserPlugin = require('terser-webpack-plugin')
const pkg = require('./package.json')
const isProd = process.env.NODE_ENV === 'production'

module.exports = {
  mode: 'production',
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'index.js',
    libraryTarget: 'commonjs2',
    library: pkg.name
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        include: path.resolve(__dirname, 'src'),
        exclude: /(node_modules|bower_components|dist)/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      }
    ]
  },
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        test: /\.js(\?.*)?$/i,
      }),
    ],
  },
  plugins: [
    new BundleAnalyzerPlugin({
      analyzerMode: isProd ? 'disabled' : 'server',
      analyzerPort: 3333,
      defaultSizes: 'gzip',
      openAnalyzer: true
    })
  ],
  externals: {
    'react': {
      commonjs: 'react',
      commonjs2: 'react',
      amd: 'React',
      root: 'React'
    },
    'prop-types': {
      commonjs: 'prop-types',
      commonjs2: 'prop-types',
      amd: 'PropTypes',
      root: 'PropTypes'
    }
  }
}