1  /*!
 2   * define-property <https://github.com/jonschlinkert/define-property>
 3   *
 4   * Copyright (c) 2015, Jon Schlinkert.
 5   * Licensed under the MIT License.
 6   */
 7  
 8  'use strict';
 9  
10  var isDescriptor = require('is-descriptor');
11  
12  module.exports = function defineProperty(obj, prop, val) {
13    if (typeof obj !== 'object' && typeof obj !== 'function') {
14      throw new TypeError('expected an object or function.');
15    }
16  
17    if (typeof prop !== 'string') {
18      throw new TypeError('expected `prop` to be a string.');
19    }
20  
21    if (isDescriptor(val) && ('set' in val || 'get' in val)) {
22      return Object.defineProperty(obj, prop, val);
23    }
24  
25    return Object.defineProperty(obj, prop, {
26      configurable: true,
27      enumerable: false,
28      writable: true,
29      value: val
30    });
31  };