webpack.prod.js

const { merge } = require('webpack-merge');
const common = require('./webpack.common');

module.exports = merge(common, {
  mode: 'production',
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: '/node_modules/',
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: ['@babel/preset-env'],
            },
          },

        ],
      },
    ],
  },
  optimization: {
    splitChunks: {
      chunks: 'async',
      minSize: 20000,
      minRemainingSize: 0,
      minChunks: 1,
      maxAsyncRequests: 30,
      maxInitialRequests: 30,
      enforceSizeThreshold: 50000,
      cacheGroups: {
        defaultVendors: {
          test: /[\\/]node_modules[\\/]/,
          priority: -10,
          reuseExistingChunk: true,
        },
        default: {
          minChunks: 2,
          priority: -20,
          reuseExistingChunk: true,
        },
      },
    },
  },
  performance: {
    hints: false,
    maxEntrypointSize: 512000,
    maxAssetSize: 512000,
  },
});