webpack-dll/webpack.react.js

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

module.exports = {
  mode: 'development',

  entry: {
    react: ['react', 'react-dom'],
  },

  output: {
    filename: '_dll_[name].js',
    path: path.resolve(__dirname, './dist'),
    library: '_dll_[name]',
    libraryTarget: 'umd',
  },

  plugins: [
    new webpack.DllPlugin({
      name: '_dll_[name]',
      path: path.resolve(__dirname, 'dist', 'manifest.json'),
    }),
  ],
};