webpack.prod.js

const merge = require('webpack-merge')
const common = require('./webpack.common.js')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const autoprefixer = require('autoprefixer')
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin')
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = merge(common, {
  mode: 'production',
  output: {
    filename: 'htmltext.min.js'
  },
  optimization: {
    minimizer: [
      new UglifyJsPlugin({
        cache: true,
        parallel: true,
        sourceMap: true // set to true if you want JS source maps
      }),
      new OptimizeCSSAssetsPlugin({})
    ]
  },
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [{
          loader: MiniCssExtractPlugin.loader
        }, {
          loader: 'css-loader'
        }, {
          loader: 'postcss-loader',
          options: {
            plugins: [
              autoprefixer({
                browsers: ['last 3 versions', '> 1%']
              })
            ]
          }
        }, {
          loader: 'sass-loader'
        }]
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'htmltext.min.css'
    })
  ]
})