/**
 * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
'use strict';

module.exports = function promisify(fn) {
  return function () {
    const args = Array.prototype.slice.call(arguments);
    return new Promise((resolve, reject) => {
      args.push((err, res) => {
        if (err) {
          reject(err);
        } else {
          resolve(res);
        }
      });

      fn.apply(this, args);
    });
  };
};