webpack.prod.js

const path = require('path');
const common = require('./webpack.common');
const { merge } = require('webpack-merge');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const ImageMinimizerPlugin = require('image-minimizer-webpack-plugin');

module.exports = merge(common, {
  mode: 'production',
  output: {
    filename: 'main.[contenthash].js',
    path: path.resolve(__dirname, 'dist'),
    assetModuleFilename: 'assets/[name].[contenthash][ext]'
  },
  optimization: {
    minimizer: [
      new OptimizeCssAssetsPlugin(),
      new TerserPlugin(),
      new ImageMinimizerPlugin({
        minimizer: {
          implementation: ImageMinimizerPlugin.imageminMinify,
          options: {
            plugins: [
              ['mozjpeg', { quality: 80 }],
              ['pngquant', { quality: [0.65, 0.80], speed: 4 }],
            ],
          },
        },
      })
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: '[name].[contenthash].css'
    }),
    new CleanWebpackPlugin()
  ],
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          MiniCssExtractPlugin.loader, // 3. Extract css into files
          'css-loader', // 2. Turns css into commonjs
          'sass-loader' // 1. Turns sass into css
        ]
      },
      {
        test: /\.css$/,
        use: [
          MiniCssExtractPlugin.loader, // 2. Extract css into files
          'css-loader' // 1. Turns css into commonjs
        ]
      }
    ]
  }
});