webpack.config.js

const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const StylelintPlugin = require('stylelint-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  devtool: 'source-map',
  externals: {
    '@popperjs/core': 'Popper'
  },
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          MiniCssExtractPlugin.loader,
          {
            loader: 'css-loader',
            options: {
              url: false
            }
          },
          'postcss-loader',
          'sass-loader'
        ]
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin(),
    new StylelintPlugin({}),
  ],
  optimization: {
    minimizer: [
      new CssMinimizerPlugin(),
      new TerserPlugin({
        extractComments: false
      })
    ]
  }
};