File: creates-a-data-descriptor.js

package info (click to toggle)
qtdeclarative-opensource-src-gles 5.15.17%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 258,992 kB
  • sloc: javascript: 512,415; cpp: 497,385; xml: 8,892; python: 3,304; ansic: 2,764; sh: 206; makefile: 46; php: 27
file content (77 lines) | stat: -rw-r--r-- 2,631 bytes parent folder | download | duplicates (11)
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
// Copyright (C) 2015 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
es6id: 26.1.13
description: >
  Creates a property data descriptor.
info: |
  26.1.13 Reflect.set ( target, propertyKey, V [ , receiver ] )

  ...
  4. If receiver is not present, then
    a. Let receiver be target.
  5. Return target.[[Set]](key, V, receiver).

  9.1.9 [[Set]] ( P, V, Receiver)

  ...
  4. If ownDesc is undefined, then
    a. Let parent be O.[[GetPrototypeOf]]().
    b. ReturnIfAbrupt(parent).
    c. If parent is not null, then
      i. Return parent.[[Set]](P, V, Receiver).
    d. Else,
      ii. Let ownDesc be the PropertyDescriptor{[[Value]]: undefined,
      [[Writable]]: true, [[Enumerable]]: true, [[Configurable]]: true}.
  5. If IsDataDescriptor(ownDesc) is true, then
    a. If ownDesc.[[Writable]] is false, return false.
    b. If Type(Receiver) is not Object, return false.
    c. Let existingDescriptor be Receiver.[[GetOwnProperty]](P).
    d. ReturnIfAbrupt(existingDescriptor).
    e. If existingDescriptor is not undefined, then
      i. If IsAccessorDescriptor(existingDescriptor) is true, return false.
      ii. If existingDescriptor.[[Writable]] is false, return false.
      iii. Let valueDesc be the PropertyDescriptor{[[Value]]: V}.
      iv. Return Receiver.[[DefineOwnProperty]](P, valueDesc).
    f. Else Receiver does not currently have a property P,
      i. Return CreateDataProperty(Receiver, P, V).
  6. Assert: IsAccessorDescriptor(ownDesc) is true.
  7. Let setter be ownDesc.[[Set]].
  8. If setter is undefined, return false.
  ...
  11. Return true.
includes: [propertyHelper.js]
---*/

var o1 = {};
var result = Reflect.set(o1, 'p', 42);
assert.sameValue(result, true, 'returns true on a successful setting');
var desc = Object.getOwnPropertyDescriptor(o1, 'p');
assert.sameValue(
  desc.value, 42,
  'sets a data descriptor to set a new property'
);
verifyWritable(o1, 'p');
verifyEnumerable(o1, 'p');
verifyConfigurable(o1, 'p');

var o2 = {};
var receiver = {};
result = Reflect.set(o2, 'p', 43, receiver);
assert.sameValue(
  result, true,
  'returns true on a successful setting with a receiver'
);
desc = Object.getOwnPropertyDescriptor(o2, 'p');
assert.sameValue(
  desc, undefined,
  'does not set a data descriptor on target if receiver is given'
);
desc = Object.getOwnPropertyDescriptor(receiver, 'p');
assert.sameValue(
  desc.value, 43,
  'sets a data descriptor on the receiver object to set a new property'
);
verifyWritable(receiver, 'p');
verifyEnumerable(receiver, 'p');
verifyConfigurable(receiver, 'p');