IcyNet.eu/webpack.prod.js

const webpack = require('webpack')
const merge = require('webpack-merge')
const common = require('./webpack.common.js')
const TerserPlugin = require('terser-webpack-plugin')

module.exports = merge(common, {
  mode: 'production',
  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('production')
    })
  ],
  optimization: {
    minimize: true,
    minimizer: [ new TerserPlugin() ]
  }
})