webpack.config.prod.js

const CleanWebpackPlugin = require('clean-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const MinifyPlugin = require("babel-minify-webpack-plugin");
const path = require('path');

module.exports = function (env, argv) {
  return {
    mode: 'production',
    entry: [
      './src/NoteManager.js'
    ],
    optimization: {
      minimizer: [
        new OptimizeCSSAssetsPlugin()
      ]
    }
    ,
    plugins: [
      new CleanWebpackPlugin(['dist']),
      new MiniCssExtractPlugin({
        filename: "[name].css",
        chunkFilename: "[id].css"
      }),
      new MinifyPlugin()
    ],
    module: {
      rules: [
        {
          test: /\.scss$/,
          use: [
            MiniCssExtractPlugin.loader,
            "css-loader",
            "sass-loader"
          ]
        },
        {
          test: /\.m?js$/,
          exclude: /(node_modules|bower_components)/,
          use: {
            loader: 'babel-loader',
            options: {
              presets: ['@babel/preset-env']
            }
          }
        }
      ]
    }
  };
}