Function callbackify

lib/util.js:401–435

* Converts a Promise-returning function to callback style * @param {Function} original * @returns {Function}

(original)

 * @returns {Function}
 */
function callbackify(original) {
  validateFunction(original, 'original');

  // We DO NOT return the promise as it gives the user a false sense that
  // the promise is actually somehow related to the callback's execution
  // and that the callback throwing will reject the promise.
  function callbackified(...args) {
    const maybeCb = ArrayPrototypePop(args);
    validateFunction(maybeCb, 'last argument');
    const cb = FunctionPrototypeBind(maybeCb, this);
    // In true node style we process the callback on `nextTick` with all the
    // implications (stack, `uncaughtException`, `async_hooks`)
    ReflectApply(original, this, args)
      .then((ret) => process.nextTick(cb, null, ret),
            (rej) => process.nextTick(callbackifyOnRejected, rej, cb));
  }

  const descriptors = ObjectGetOwnPropertyDescriptors(original);
  // It is possible to manipulate a functions `length` or `name` property. This
  // guards against the manipulation.
  if (typeof descriptors.length.value === 'number') {
    descriptors.length.value++;
  }
  if (typeof descriptors.name.value === 'string') {
    descriptors.name.value += 'Callbackified';
  }
  const propertiesValues = ObjectValues(descriptors);
  for (let i = 0; i < propertiesValues.length; i++) {
  // We want to use null-prototype objects to not rely on globally mutable
  // %Object.prototype%.
    ObjectSetPrototypeOf(propertiesValues[i], null);
  }
  ObjectDefineProperties(callbackified, descriptors);
  return callbackified;
}

/**
 * @param {number} err