3 var hasOwn = Object.prototype.hasOwnProperty;
4 var toStr = Object.prototype.toString;
6 var isArray = function isArray(arr) {
7 if (typeof Array.isArray === 'function') {
8 return Array.isArray(arr);
11 return toStr.call(arr) === '[object Array]';
14 var isPlainObject = function isPlainObject(obj) {
15 if (!obj || toStr.call(obj) !== '[object Object]') {
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) {
26 // Own properties are enumerated firstly, so to speed up,
27 // if last one is own, then all properties are own.
29 for (key in obj) {/**/}
31 return typeof key === 'undefined' || hasOwn.call(obj, key);
34 module.exports = function extend() {
35 var options, name, src, copy, copyIsArray, clone,
36 target = arguments[0],
38 length = arguments.length,
41 // Handle a deep copy situation
42 if (typeof target === 'boolean') {
44 target = arguments[1] || {};
45 // skip the boolean and the target
47 } else if ((typeof target !== 'object' && typeof target !== 'function') || target == null) {
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) {
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)))) {
66 clone = src && isArray(src) ? src : [];
68 clone = src && isPlainObject(src) ? src : {};
71 // Never move original objects, clone them
72 target[name] = extend(deep, clone, copy);
74 // Don't bring in undefined values
75 } else if (typeof copy !== 'undefined') {
83 // Return the modified object