make-bundle.js

const path = require("path");
const webpack = require('webpack');

function makeBundle({ outputPath, projectPath, watch = false }) {
  const webpackConfig = require(path.resolve(projectPath, "webpack.config.js"));

  return new Promise((resolve, reject) => {
    const webpackCompiler = webpack(webpackConfig);

    const postRun = (error, stats) => {
        if (stats.hasErrors()) {
          reject();
        }

        resolve();
    };

    if (watch) {
      return webpackCompiler.watch({}, postRun);
    }

    return webpackCompiler.run(postRun);

  });
}

module.exports = makeBundle;