clone.js
8.3 KB
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
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
/* eslint-disable */
var clone = (function() {
'use strict';
function _instanceof(obj, type) {
return type != null && obj instanceof type;
}
var nativeMap;
try {
nativeMap = Map;
} catch(_) {
// maybe a reference error because no `Map`. Give it a dummy value that no
// value will ever be an instanceof.
nativeMap = function() {};
}
var nativeSet;
try {
nativeSet = Set;
} catch(_) {
nativeSet = function() {};
}
var nativePromise;
try {
nativePromise = Promise;
} catch(_) {
nativePromise = function() {};
}
/**
* Clones (copies) an Object using deep copying.
*
* This function supports circular references by default, but if you are certain
* there are no circular references in your object, you can save some CPU time
* by calling clone(obj, false).
*
* Caution: if `circular` is false and `parent` contains circular references,
* your program may enter an infinite loop and crash.
*
* @param `parent` - the object to be cloned
* @param `circular` - set to true if the object to be cloned may contain
* circular references. (optional - true by default)
* @param `depth` - set to a number if the object is only to be cloned to
* a particular depth. (optional - defaults to Infinity)
* @param `prototype` - sets the prototype to be used when cloning an object.
* (optional - defaults to parent prototype).
* @param `includeNonEnumerable` - set to true if the non-enumerable properties
* should be cloned as well. Non-enumerable properties on the prototype
* chain will be ignored. (optional - false by default)
*/
function clone(parent, circular, depth, prototype, includeNonEnumerable) {
if (typeof circular === 'object') {
depth = circular.depth;
prototype = circular.prototype;
includeNonEnumerable = circular.includeNonEnumerable;
circular = circular.circular;
}
// maintain two arrays for circular references, where corresponding parents
// and children have the same index
var allParents = [];
var allChildren = [];
var useBuffer = typeof Buffer != 'undefined';
if (typeof circular == 'undefined')
circular = true;
if (typeof depth == 'undefined')
depth = Infinity;
// recurse this function so we don't reset allParents and allChildren
function _clone(parent, depth) {
// cloning null always returns null
if (parent === null)
return null;
if (depth === 0)
return parent;
var child;
var proto;
if (typeof parent != 'object') {
return parent;
}
if (_instanceof(parent, nativeMap)) {
child = new nativeMap();
} else if (_instanceof(parent, nativeSet)) {
child = new nativeSet();
} else if (_instanceof(parent, nativePromise)) {
child = new nativePromise(function (resolve, reject) {
parent.then(function(value) {
resolve(_clone(value, depth - 1));
}, function(err) {
reject(_clone(err, depth - 1));
});
});
} else if (clone.__isArray(parent)) {
child = [];
} else if (clone.__isRegExp(parent)) {
child = new RegExp(parent.source, __getRegExpFlags(parent));
if (parent.lastIndex) child.lastIndex = parent.lastIndex;
} else if (clone.__isDate(parent)) {
child = new Date(parent.getTime());
} else if (useBuffer && Buffer.isBuffer(parent)) {
if (Buffer.from) {
// Node.js >= 5.10.0
child = Buffer.from(parent);
} else {
// Older Node.js versions
child = new Buffer(parent.length);
parent.copy(child);
}
return child;
} else if (_instanceof(parent, Error)) {
child = Object.create(parent);
} else {
if (typeof prototype == 'undefined') {
proto = Object.getPrototypeOf(parent);
child = Object.create(proto);
}
else {
child = Object.create(prototype);
proto = prototype;
}
}
if (circular) {
var index = allParents.indexOf(parent);
if (index != -1) {
return allChildren[index];
}
allParents.push(parent);
allChildren.push(child);
}
if (_instanceof(parent, nativeMap)) {
parent.forEach(function(value, key) {
var keyChild = _clone(key, depth - 1);
var valueChild = _clone(value, depth - 1);
child.set(keyChild, valueChild);
});
}
if (_instanceof(parent, nativeSet)) {
parent.forEach(function(value) {
var entryChild = _clone(value, depth - 1);
child.add(entryChild);
});
}
for (var i in parent) {
var attrs = Object.getOwnPropertyDescriptor(parent, i);
if (attrs) {
child[i] = _clone(parent[i], depth - 1);
}
try {
var objProperty = Object.getOwnPropertyDescriptor(parent, i);
if (objProperty.set === 'undefined') {
// no setter defined. Skip cloning this property
continue;
}
child[i] = _clone(parent[i], depth - 1);
} catch(e){
if (e instanceof TypeError) {
// when in strict mode, TypeError will be thrown if child[i] property only has a getter
// we can't do anything about this, other than inform the user that this property cannot be set.
continue
} else if (e instanceof ReferenceError) {
//this may happen in non strict mode
continue
}
}
}
if (Object.getOwnPropertySymbols) {
var symbols = Object.getOwnPropertySymbols(parent);
for (var i = 0; i < symbols.length; i++) {
// Don't need to worry about cloning a symbol because it is a primitive,
// like a number or string.
var symbol = symbols[i];
var descriptor = Object.getOwnPropertyDescriptor(parent, symbol);
if (descriptor && !descriptor.enumerable && !includeNonEnumerable) {
continue;
}
child[symbol] = _clone(parent[symbol], depth - 1);
Object.defineProperty(child, symbol, descriptor);
}
}
if (includeNonEnumerable) {
var allPropertyNames = Object.getOwnPropertyNames(parent);
for (var i = 0; i < allPropertyNames.length; i++) {
var propertyName = allPropertyNames[i];
var descriptor = Object.getOwnPropertyDescriptor(parent, propertyName);
if (descriptor && descriptor.enumerable) {
continue;
}
child[propertyName] = _clone(parent[propertyName], depth - 1);
Object.defineProperty(child, propertyName, descriptor);
}
}
return child;
}
return _clone(parent, depth);
}
/**
* Simple flat clone using prototype, accepts only objects, usefull for property
* override on FLAT configuration object (no nested props).
*
* USE WITH CAUTION! This may not behave as you wish if you do not know how this
* works.
*/
clone.clonePrototype = function clonePrototype(parent) {
if (parent === null)
return null;
var c = function () {};
c.prototype = parent;
return new c();
};
// private utility functions
function __objToStr(o) {
return Object.prototype.toString.call(o);
}
clone.__objToStr = __objToStr;
function __isDate(o) {
return typeof o === 'object' && __objToStr(o) === '[object Date]';
}
clone.__isDate = __isDate;
function __isArray(o) {
return typeof o === 'object' && __objToStr(o) === '[object Array]';
}
clone.__isArray = __isArray;
function __isRegExp(o) {
return typeof o === 'object' && __objToStr(o) === '[object RegExp]';
}
clone.__isRegExp = __isRegExp;
function __getRegExpFlags(re) {
var flags = '';
if (re.global) flags += 'g';
if (re.ignoreCase) flags += 'i';
if (re.multiline) flags += 'm';
return flags;
}
clone.__getRegExpFlags = __getRegExpFlags;
return clone;
})();
export default clone