webpack.prod.js

const path = require('path');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const CompressionPlugin = require('compression-webpack-plugin');
const merge = require('webpack-merge');

const common = require('./webpack.config');
const BUILD_DIR = path.resolve(__dirname, 'dist');

module.exports = merge(common, {
  output: {
    path: BUILD_DIR,
    filename: 'bundle.[hash].js',
    chunkFilename: '[name].[hash].chunk.js',
  },
  mode: 'production',
  module: {
    rules: [
      {
        enforce: 'pre',
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: 'eslint-loader',
      },
      {
        test: /\.css$/,
        use: [MiniCssExtractPlugin.loader, 'css-loader'],
      },
      {
        test: /\.scss$/,
        use: [MiniCssExtractPlugin.loader, 'css-loader', 'sass-loader'],
      },
    ],
  },
  plugins: [
    new CleanWebpackPlugin([BUILD_DIR]),
    new MiniCssExtractPlugin({
      filename: 'bundle.[hash].css',
    }),
    new CompressionPlugin({
      algorithm: 'gzip',
      test: /\.jsx?$|\.s?css$/,
      minRatio: 0.8,
    }),
  ],
  performance: {
    hints: 'warning',
  },
});