test262/test/built-ins/Object/assign/target-is-non-extensible-ex...

58 lines
1.7 KiB
JavaScript

// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
// This code is governed by the license found in the LICENSE file.
/*---
esid: sec-object.assign
description: >
[[Set]] to existing data property of non-extensible `target` is successful.
info: |
OrdinaryPreventExtensions ( O )
1. Set O.[[Extensible]] to false.
Object.assign ( target, ...sources )
[...]
3. For each element nextSource of sources, do
a. If nextSource is neither undefined nor null, then
[...]
iii. For each element nextKey of keys, do
1. Let desc be ? from.[[GetOwnProperty]](nextKey).
2. If desc is not undefined and desc.[[Enumerable]] is true, then
[...]
b. Perform ? Set(to, nextKey, propValue, true).
OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
[...]
3. If IsDataDescriptor(ownDesc) is true, then
[...]
c. Let existingDescriptor be ? Receiver.[[GetOwnProperty]](P).
d. If existingDescriptor is not undefined, then
[...]
iii. Let valueDesc be the PropertyDescriptor { [[Value]]: V }.
iv. Return ? Receiver.[[DefineOwnProperty]](P, valueDesc).
ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current )
[...]
9. If O is not undefined, then
a. For each field of Desc that is present, set the corresponding attribute
of the property named P of object O to the value of the field.
10. Return true.
features: [Symbol]
---*/
var target1 = Object.preventExtensions({ foo: 1 });
Object.assign(target1, { foo: 2 });
assert.sameValue(target1.foo, 2);
var sym = Symbol();
var target2 = { [sym]: 1 };
Object.preventExtensions(target2);
Object.assign(target2, { [sym]: 2 });
assert.sameValue(target2[sym], 2);