-
Notifications
You must be signed in to change notification settings - Fork 7
/
extend.js
83 lines (65 loc) · 1.92 KB
/
extend.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
/***********************************************************************
@class decal
************************************************************************/
'use strict'
const isObject = require('./isObject')
const isFunction = require('./isFunction')
/***********************************************************************
Used by `decal.CoreObject` for inheritance and mixins.
@method extend
@private
************************************************************************/
function isPlainObject (o) {
return isObject(o) && o.constructor === Object
}
function isArray (a) {
return Array.isArray(a)
}
function extend (target) {
var i,
l,
src,
clone,
copy,
deep,
name,
options,
copyIsArray
// Handle case when target is a string or something (possible in deep copy)
if (typeof target !== 'object' && !isFunction(target)) {
target = {}
}
i = isObject(arguments[1]) ? 1 : 2
deep = (arguments[1] === true)
for (l = arguments.length; i < l; i++) {
// Only deal with non-null/undefined values
if ((options = arguments[i]) != null) {
// Extend the base object
for (name in options) {
src = target[name]
copy = options[name]
// Prevent never-ending loop
if (target === copy) {
continue
}
// Recurse if we're merging plain objects or arrays
if (deep && copy && (isPlainObject(copy) || (copyIsArray = isArray(copy)))) {
if (copyIsArray) {
copyIsArray = false
clone = src && isArray(src) ? src : []
} else {
clone = src && isPlainObject(src) ? src : {}
}
// Never move original objects, clone them
target[name] = extend(clone, deep, copy)
}
// Don't bring in undefined values
else if (copy !== undefined) {
target[name] = copy
}
}
}
}
return target
}
module.exports = extend