webpack.prod.js

const merge                   = require('webpack-merge');
const TerserPlugin            = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const MiniCssExtractPlugin    = require('mini-css-extract-plugin');

const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'production',

  output: {
    filename:      '[name].[hash:5].js',
    chunkFilename: '[id].[hash:5].css',
  },

  optimization: {
    minimizer: [
      new TerserPlugin({
        cache:     true,
        parallel:  true,
        sourceMap: true,
        exclude:   /\/node_modules\//,
      }),
      new MiniCssExtractPlugin({
        filename:      '[name].[hash:5].css',
        chunkFilename: '[id].[hash:5].css',
      }),
      new OptimizeCSSAssetsPlugin({}),
    ],
  },
});