1  /*!
 2   * is-data-descriptor <https://github.com/jonschlinkert/is-data-descriptor>
 3   *
 4   * Copyright (c) 2015, Jon Schlinkert.
 5   * Licensed under the MIT License.
 6   */
 7  
 8  'use strict';
 9  
10  var typeOf = require('kind-of');
11  
12  // data descriptor properties
13  var data = {
14    configurable: 'boolean',
15    enumerable: 'boolean',
16    writable: 'boolean'
17  };
18  
19  function isDataDescriptor(obj, prop) {
20    if (typeOf(obj) !== 'object') {
21      return false;
22    }
23  
24    if (typeof prop === 'string') {
25      var val = Object.getOwnPropertyDescriptor(obj, prop);
26      return typeof val !== 'undefined';
27    }
28  
29    if (!('value' in obj) && !('writable' in obj)) {
30      return false;
31    }
32  
33    for (var key in obj) {
34      if (key === 'value') continue;
35  
36      if (!data.hasOwnProperty(key)) {
37        continue;
38      }
39  
40      if (typeOf(obj[key]) === data[key]) {
41        continue;
42      }
43  
44      if (typeof obj[key] !== 'undefined') {
45        return false;
46      }
47    }
48    return true;
49  }
50  
51  /**
52   * Expose `isDataDescriptor`
53   */
54  
55  module.exports = isDataDescriptor;