webpack.prod.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const HardSourceWebpackPlugin = require('hard-source-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const WorkboxPlugin = require('workbox-webpack-plugin');

module.exports = {
  mode: 'production',
  entry: './src/index.js',
  devtool: 'cheap-module-source-map',
  output: {
    filename: 'bundle_[hash].js',
    path: path.resolve(__dirname, 'dist')
  },
  resolve: {
    extensions: ['.js', '.jsx']
  },
  module: {
    rules: [
      {
        test: /\.(png|jpg|gif|svg|eot|ttf|woff|woff2)?$/,
        use: [
          {
            loader: 'url-loader',
            options: {
              limit: 20480
            }
          }
        ]
      },
      {
        test: /\.(js|jsx)?$/,
        exclude: /node_modules/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: ['@babel/preset-env', '@babel/preset-react'],
              plugins: [
                ['@babel/plugin-proposal-decorators', { legacy: true }],
                ['@babel/plugin-proposal-class-properties', { loose: true }],
                ['@babel/plugin-transform-runtime']
              ]
            }
          },
          require.resolve('./src/loaders/i18n.js')
        ]
      },
      {
        test: /\.(sass|scss)?$/,
        use: [
          'style-loader',
          {
            loader: 'css-loader',
            options: {
              importLoaders: 2
            }
          },
          'postcss-loader',
          'sass-loader'
        ]
      },
      {
        test: /\.css?$/,
        use: ['style-loader', 'css-loader', 'postcss-loader']
      }
    ]
  },
  optimization: {
    usedExports: true,
    splitChunks: {
      chunks: 'async',
      minSize: 30000,
      maxSize: 0,
      minChunks: 1,
      maxAsyncRequests: 5,
      maxInitialRequests: 3,
      automaticNameDelimiter: '~',
      automaticNameMaxLength: 30,
      name: true,
      cacheGroups: {
        vendors: {
          test: /[\\/]node_modules[\\/]/,
          priority: -10
        },
        default: {
          minChunks: 2,
          priority: -20,
          reuseExistingChunk: true
        }
      }
    }
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './index.html'
    }),
    new CleanWebpackPlugin(),
    new WorkboxPlugin.GenerateSW({
      skipWaiting: true,
      clientsClaim: true
    }),
    new HardSourceWebpackPlugin()
  ]
};