webpack.config.js

const path = require('path');
const LodashModuleReplacementPlugin = require('lodash-webpack-plugin');
const pkg = require('./package.json');

module.exports = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'lib'),
    filename: 'index.js',
    library: '',
    libraryTarget: 'commonjs',
  },
  module: {
    rules: [
      {
        test: /\.(gif|svg|jpg|png)$/,
        loader: 'file-loader',
      },
      {
        test: /\.m?js$/,
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env'],
          },
        },
      },
      {
        test: /\.css$/i,
        use: ['style-loader', 'css-loader'],
      },
    ],
  },
  plugins: [
    new LodashModuleReplacementPlugin,
  ],
  externals: [
    {
      react: {
        root: 'React',
        commonjs2: 'react',
        commonjs: 'react',
        amd: 'react',
      },
      'react-dom': {
        root: 'ReactDOM',
        commonjs2: 'react-dom',
        commonjs: 'react-dom',
        amd: 'react-dom',
      },
    },
    /^(@material-ui(\/.*)?)$/,
    /^(leaflet(\/.*)?)$/,
  ],
};