node.d/node_modules/extend.js

   1 // https://github.com/justmoon/node-extend
   2
   3 'use strict';
   4
   5 var hasOwn = Object.prototype.hasOwnProperty;
   6 var toStr = Object.prototype.toString;
   7
   8 var isArray = function isArray(arr) {
   9         if (typeof Array.isArray === 'function') {
  10                 return Array.isArray(arr);
  11         }
  12
  13         return toStr.call(arr) === '[object Array]';
  14 };
  15
  16 var isPlainObject = function isPlainObject(obj) {
  17         if (!obj || toStr.call(obj) !== '[object Object]') {
  18                 return false;
  19         }
  20
  21         var hasOwnConstructor = hasOwn.call(obj, 'constructor');
  22         var hasIsPrototypeOf = obj.constructor && obj.constructor.prototype && hasOwn.call(obj.constructor.prototype, 'isPrototypeOf');
  23         // Not own constructor property must be Object
  24         if (obj.constructor && !hasOwnConstructor && !hasIsPrototypeOf) {
  25                 return false;
  26         }
  27
  28         // Own properties are enumerated firstly, so to speed up,
  29         // if last one is own, then all properties are own.
  30         var key;
  31         for (key in obj) { /**/ }
  32
  33         return typeof key === 'undefined' || hasOwn.call(obj, key);
  34 };
  35
  36 module.exports = function extend() {
  37         var options, name, src, copy, copyIsArray, clone;
  38         var target = arguments[0];
  39         var i = 1;
  40         var length = arguments.length;
  41         var deep = false;
  42
  43         // Handle a deep copy situation
  44         if (typeof target === 'boolean') {
  45                 deep = target;
  46                 target = arguments[1] || {};
  47                 // skip the boolean and the target
  48                 i = 2;
  49         } else if ((typeof target !== 'object' && typeof target !== 'function') || target == null) {
  50                 target = {};
  51         }
  52
  53         for (; i < length; ++i) {
  54                 options = arguments[i];
  55                 // Only deal with non-null/undefined values
  56                 if (options != null) {
  57                         // Extend the base object
  58                         for (name in options) {
  59                                 src = target[name];
  60                                 copy = options[name];
  61
  62                                 // Prevent never-ending loop
  63                                 if (target !== copy) {
  64                                         // Recurse if we're merging plain objects or arrays
  65                                         if (deep && copy && (isPlainObject(copy) || (copyIsArray = isArray(copy)))) {
  66                                                 if (copyIsArray) {
  67                                                         copyIsArray = false;
  68                                                         clone = src && isArray(src) ? src : [];
  69                                                 } else {
  70                                                         clone = src && isPlainObject(src) ? src : {};
  71                                                 }
  72
  73                                                 // Never move original objects, clone them
  74                                                 target[name] = extend(deep, clone, copy);
  75
  76                                         // Don't bring in undefined values
  77                                         } else if (typeof copy !== 'undefined') {
  78                                                 target[name] = copy;
  79                                         }
  80                                 }
  81                         }
  82                 }
  83         }
  84
  85         // Return the modified object
  86         return target;
  87 };