webpack.config.js

const path = require('path');
const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  mode: "production",
  entry: {
    rLocker: path.resolve(__dirname, "inst/www/js/src/app.js"),
  },
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          keep_classnames: true,
          keep_fnames: true
        },
        extractComments: {
          condition: /^\**!|@preserve|@license|@cc_on/i,
          filename: (fileData) => {
            // The "fileData" argument contains object with "filename", "basename", "query" and "hash"
            return `${fileData.filename}.LICENSES.txt${fileData.query}`;
          },
          banner: (licenseFile) => {
            return `License information can be found in ${licenseFile}`;
          },
        },
        test: /\.js(\?.*)?$/i,
      }),
    ],
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader'
        }
      },
    ]
  },
  output: {
    path: path.resolve(__dirname, "inst/www/js/dist/"),
    filename: "[name].js",
  }
};