webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');

const isProd = process.env.NODE_ENV === 'production';
const isDev = !isProd;

module.exports = {
  entry: {
    main: './src/index.js',
  },
  output: {
    filename: isDev ? '[name].js' : '[name].[contenthash].js',
    path: path.resolve(__dirname, 'dist'),
    clean: true,
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: 'index.html',
    }),
    new MiniCssExtractPlugin({
      filename: isDev ? '[name].css' : '[name].[hash].css',
    }),
  ],
  resolve: {
    extensions: ['.js', '.json'],
    alias: {
      '@styles': path.resolve(__dirname, 'src/styles'),
      '@': path.resolve(__dirname, 'src'),
    },
  },
  devServer: {
    static: {
      directory: path.join(__dirname, 'public'),
    },
    compress: true,
    hot: isDev,
  },
  devtool: isDev ? 'source-map' : false,
  optimization: {
    minimizer: [new CssMinimizerPlugin()],
    runtimeChunk: 'single',
    splitChunks: {
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name: 'vendors',
          chunks: 'all',
        },
      },
    },
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: '/node_modules/',
        options: {
          presets: ['@babel/env'],
        },
      },
      {
        test: /\.css$/i,
        use: [MiniCssExtractPlugin.loader, { loader: 'css-loader', options: { sourceMap: true } }],
      },
      {
        test: /\.s[ac]ss$/i,
        use: [
          MiniCssExtractPlugin.loader,
          { loader: 'css-loader', options: { sourceMap: true } },
          { loader: 'sass-loader', options: { sourceMap: true } },
        ],
      },
    ],
  },
};