www.aleph1.co.uk Git - yaffs-website/blob - node_modules/extend/index.js

   1 'use strict';
   2
   3 var hasOwn = Object.prototype.hasOwnProperty;
   4 var toStr = Object.prototype.toString;
   5
   6 var isArray = function isArray(arr) {
   7         if (typeof Array.isArray === 'function') {
   8                 return Array.isArray(arr);
   9         }
  10
  11         return toStr.call(arr) === '[object Array]';
  12 };
  13
  14 var isPlainObject = function isPlainObject(obj) {
  15         if (!obj || toStr.call(obj) !== '[object Object]') {
  16                 return false;
  17         }
  18
  19         var hasOwnConstructor = hasOwn.call(obj, 'constructor');
  20         var hasIsPrototypeOf = obj.constructor && obj.constructor.prototype && hasOwn.call(obj.constructor.prototype, 'isPrototypeOf');
  21         // Not own constructor property must be Object
  22         if (obj.constructor && !hasOwnConstructor && !hasIsPrototypeOf) {
  23                 return false;
  24         }
  25
  26         // Own properties are enumerated firstly, so to speed up,
  27         // if last one is own, then all properties are own.
  28         var key;
  29         for (key in obj) {/**/}
  30
  31         return typeof key === 'undefined' || hasOwn.call(obj, key);
  32 };
  33
  34 module.exports = function extend() {
  35         var options, name, src, copy, copyIsArray, clone,
  36                 target = arguments[0],
  37                 i = 1,
  38                 length = arguments.length,
  39                 deep = false;
  40
  41         // Handle a deep copy situation
  42         if (typeof target === 'boolean') {
  43                 deep = target;
  44                 target = arguments[1] || {};
  45                 // skip the boolean and the target
  46                 i = 2;
  47         } else if ((typeof target !== 'object' && typeof target !== 'function') || target == null) {
  48                 target = {};
  49         }
  50
  51         for (; i < length; ++i) {
  52                 options = arguments[i];
  53                 // Only deal with non-null/undefined values
  54                 if (options != null) {
  55                         // Extend the base object
  56                         for (name in options) {
  57                                 src = target[name];
  58                                 copy = options[name];
  59
  60                                 // Prevent never-ending loop
  61                                 if (target !== copy) {
  62                                         // Recurse if we're merging plain objects or arrays
  63                                         if (deep && copy && (isPlainObject(copy) || (copyIsArray = isArray(copy)))) {
  64                                                 if (copyIsArray) {
  65                                                         copyIsArray = false;
  66                                                         clone = src && isArray(src) ? src : [];
  67                                                 } else {
  68                                                         clone = src && isPlainObject(src) ? src : {};
  69                                                 }
  70
  71                                                 // Never move original objects, clone them
  72                                                 target[name] = extend(deep, clone, copy);
  73
  74                                         // Don't bring in undefined values
  75                                         } else if (typeof copy !== 'undefined') {
  76                                                 target[name] = copy;
  77                                         }
  78                                 }
  79                         }
  80                 }
  81         }
  82
  83         // Return the modified object
  84         return target;
  85 };
  86