webpack.prod.js

const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const TerserPlugin = require("terser-webpack-plugin")
const { CleanWebpackPlugin } = require('clean-webpack-plugin')
const { merge } = require('webpack-merge')
const common = require('./webpack.common')

module.exports = merge(common, {
  mode: 'production',
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: '/node_modules/',
        use: 'babel-loader'
      },
      {
        test: /\.css$/i,
        use: [MiniCssExtractPlugin.loader, "css-loader"],
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin(),
    new CleanWebpackPlugin()
  ],
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin()],
    runtimeChunk: 'single',
    splitChunks: {
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name: 'vendors',
          chunks: 'all'
        }
      }
    }
  }
})