webpack.config.js

const path = require('path')
const glob = require('glob-all')
const CleanWebpackPlugin = require('clean-webpack-plugin')
const UglifyJsPlugin = require("uglifyjs-webpack-plugin")
const MiniCssExtractPlugin = require("mini-css-extract-plugin")
const PurgecssPlugin = require('purgecss-webpack-plugin')
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin")
const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: './src/index.js',
  mode: process.env.NODE_ENV,
  module: {
    rules: [
      {
        test: /\.html$/,
        use: {
          loader: 'html-loader'
        }
      },
      {
        test: /\.m?js$/,
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      },
      {
        test: /\.(sa|sc|c)ss$/,
        use: [
          'style-loader',
          { loader: 'css-loader', options: { importLoaders: 2 } },
          'postcss-loader',
          'sass-loader'
        ]
      },
      {
        test: /\.(png|jpg|jpeg|gif|ico)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: '[name].[ext]'
            }
          }
        ]
      }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(['dist'], { verbose: true }),
    new MiniCssExtractPlugin({
      filename: '[name].[hash].css',
      chunkFilename: '[id].[hash].css'
    }),
    new PurgecssPlugin({
      paths: () => glob.sync([
        path.join(__dirname, './src/index.js'),
        path.join(__dirname, './src/style.css'),
        path.join(__dirname, './src/index.html'),
        path.join(__dirname, './src/components/*.js'),
        path.join(__dirname, './src/templates/*.html')
      ])
    }),
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'src/index.html',
    })
  ],
  optimization: {
    minimizer: [
      new UglifyJsPlugin({
        cache: true,
        parallel: true,
        sourceMap: true
      }),
      new OptimizeCSSAssetsPlugin({})
    ],
    splitChunks: {
      chunks: 'all'
    }
  },
  output: {
    filename: 'main.[hash].js',
    path: path.resolve(__dirname, 'dist')
  },
  devServer: {
    contentBase: path.join(__dirname, 'dist'),
    compress: true,
    port: 9000
  }
}