webpack.config.js

const path = require('path');

module.exports = {
   mode: 'production',
   entry: './src/index.js',
   output: {
      path: path.resolve('dist'),
      filename: 'TimePicker.js',
      libraryTarget: 'commonjs2',
   },
   module: {
      rules: [
         {
            test: /\.js?$/,
            exclude: /(node_modules)/,
            use: 'babel-loader',
         },
         {
            test: /\.css$/,
            use: ['style-loader', 'css-loader'],
         },
      ],
   },
   resolve: {
      alias: {
         react: path.resolve(__dirname, './node_modules/react'),
         'react-dom': path.resolve(__dirname, './node_modules/react-dom'),
      },
   },
   externals: {
      // Don't bundle react or react-dom
      react: {
         commonjs: 'react',
         commonjs2: 'react',
         amd: 'React',
         root: 'React',
      },
      'react-dom': {
         commonjs: 'react-dom',
         commonjs2: 'react-dom',
         amd: 'ReactDOM',
         root: 'ReactDOM',
      },
   },
};