webpack.config.js

const path = require('path')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const TerserPlugin = require('terser-webpack-plugin')
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin')

module.exports = {
  entry: './src/cato.js',
  output: {
    filename: 'cato.min.js',
    path: path.resolve(__dirname, 'dest'),
    library: 'Cato',
    libraryExport: 'default',
    libraryTarget: 'umd',
  },
  optimization: {
    minimizer: [
      new TerserPlugin({
        cache: true,
        parallel: true,
        sourceMap: true, // set to true if you want JS source maps
      }),
      new OptimizeCSSAssetsPlugin({}),
    ],
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'cato.min.css',
    }),
  ],
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
          },
          'css-loader',
        ],
      },
    ],
  },
}