v8/test/mjsunit/regress/regress-595319.js
littledan 7acee1ef61 Throw the right exceptions from setting elements in Array.prototype.concat
This patch fixes two bugs in Array.prototype.concat in conjunction with
subclassing Arrays:
- Create a new property rather than calling Set when adding elements to
  the output array. This means setters are not called.
- If there is an exception thrown from DefineProperty, propagate it
  outwards properly, rather than swallowing it. This can occur, e.g., with
  a Proxy as the new output array.

R=adamk
LOG=Y
BUG=chromium:595319

Review URL: https://codereview.chromium.org/1814933002

Cr-Commit-Position: refs/heads/master@{#34876}
2016-03-17 22:42:00 +00:00

40 lines
1.4 KiB
JavaScript

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// https://bugs.chromium.org/p/chromium/issues/detail?id=595319
// Ensure exceptions are checked for by Array.prototype.concat from adding
// an element, and that elements are added to array subclasses appropriately
// If adding a property does throw, the exception is propagated
class MyException extends Error { }
class NoDefinePropertyArray extends Array {
constructor(...args) {
super(...args);
return new Proxy(this, {
defineProperty() { throw new MyException(); }
});
}
}
assertThrows(() => new NoDefinePropertyArray().concat([1]), MyException);
// Ensure elements are added to the instance, rather than calling [[Set]].
class ZeroGetterArray extends Array { get 0() {} };
assertArrayEquals([1], new ZeroGetterArray().concat(1));
// Frozen arrays lead to throwing
class FrozenArray extends Array {
constructor(...args) { super(...args); Object.freeze(this); }
}
assertThrows(() => new FrozenArray().concat([1]), TypeError);
// Non-configurable non-writable zero leads to throwing
class ZeroFrozenArray extends Array {
constructor(...args) {
super(...args);
Object.defineProperty(this, 0, {value: 1});
}
}
assertThrows(() => new ZeroFrozenArray().concat([1]), TypeError);