Edit File: webpack.config.js
const path = require('path'); module.exports = (env, argv) => { let production = argv.mode === 'production' return { entry: { 'rucss-progress-bar': path.resolve(__dirname, 'src/js/react/rucss-progress-bar.js'), }, output: { filename: '[name].js', path: path.resolve(__dirname, 'assets/js/react/'), }, devtool: production ? '' : 'source-map', resolve: { extensions: [".js", ".jsx", ".json"], }, module: { rules: [ { test: /\.jsx?$/, exclude: /node_modules/, loader: 'babel-loader', }, ], }, }; }