webpack.config.js

module.exports = {
  mode: 'production', // "production" | "development" | "none"
  // Chosen mode tells webpack to use its built-in optimizations accordingly.
  entry: './src/exports.js',
  output: {
    libraryTarget: "umd"
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        use: 'babel-loader',
      },
      {
        test: /\.css$/i,
        use: ['style-loader', 'css-loader'],
      },
    ],
  },
  externals: {
    moment: {
      commonjs: 'moment',
      commonjs2: 'moment',
      amd: 'moment',
      root: 'moment',
    },
    react: {
      commonjs: 'react',
      commonjs2: 'react',
      amd: 'react',
      root: 'react',
    },
    "react-dom": {
      commonjs: 'react-dom',
      commonjs2: 'react-dom',
      amd: 'react-dom',
      root: '-',
    },
    "prop-types": {
      commonjs: 'prop-types',
      commonjs2: 'prop-types',
      amd: 'prop-types',
      root: 'PropTypes',
    },
  }
}