webpack.prod.js

const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const TerserPlugin = require("terser-webpack-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CopyWebpackPlugin = require('copy-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = merge(common, {
  mode: 'production',
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        cache: true,
        parallel: true
      }),
      new OptimizeCSSAssetsPlugin({})
    ],
    splitChunks: {
      chunks: 'all'
    }
  },
  plugins: [
    new CleanWebpackPlugin(),
    new MiniCssExtractPlugin({
      filename: "[name].[hash].css",
      chunkFilename: "[id].[hash].css"
    }),
    new CopyWebpackPlugin({
      patterns: [
        {from: 'manifest.json', to: 'manifest.json'}
      ]
    })
  ],
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          MiniCssExtractPlugin.loader,
          'css-loader'
        ]    
      },
      {
        test: /\.(png|jpeg)$/,
        use: [
          'file-loader'
        ]
      },
      {
        test: /\.(woff|woff2)$/,
        use: [
          'file-loader'
        ]
      },
      {
        test: /\.html$/,
        use: [
          'html-loader'
        ]
      }
    ]
  }
});