webpack.prod.js

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

module.exports = merge(common, {
  mode: 'production',
  devtool: 'source-map',
  optimization: {
    usedExports: true,
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          cache: true,
          keep_fnames: true,
          output: {comments: false},
          parallel: true,
          sourceMap: true,
        },
      }),
      new OptimizeCSSAssetsPlugin({})
    ]
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'eslint-loader',
        options: {
          formatter: require('eslint/lib/formatters/stylish')
        }
      }
    ]
  }
})