test262/test/built-ins/Proxy/preventExtensions/trap-is-null-target-is-prox...

28 lines
878 B
JavaScript

// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-proxy-object-internal-methods-and-internal-slots-preventextensions
description: >
If "preventExtensions" trap is null or undefined, [[PreventExtensions]] call
is properly forwarded to [[ProxyTarget]] (which is also a Proxy object).
info: |
[[PreventExtensions]] ( )
[...]
4. Let target be O.[[ProxyTarget]].
5. Let trap be ? GetMethod(handler, "preventExtensions").
6. If trap is undefined, then
a. Return ? target.[[PreventExtensions]]().
features: [Proxy]
---*/
var plainObject = {};
var plainObjectTarget = new Proxy(plainObject, {});
var plainObjectProxy = new Proxy(plainObjectTarget, {
preventExtensions: null,
});
Object.preventExtensions(plainObjectProxy);
assert(!Object.isExtensible(plainObject));