v8/test/mjsunit/regress/regress-7677.js

// Copyright 2018 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.

"use strict";

// Generate a frozen or sealed array-like object.
function arraylike(freeze) {
  let x;
  const obj = {length: 42};
  Object.defineProperty(obj, 5, {get() {return x}, set(y) {x = y}});
  return freeze ? Object.freeze(obj) : Object.seal(obj);
}

// Array.prototype.fill
{
  const sealed = arraylike(false);
  Array.prototype.fill.call(sealed, "foo", 5, 6);
  assertEquals("foo", sealed[5]);
  assertThrows(() => Array.prototype.fill.call(sealed, "foo"), TypeError);
}{
  const frozen = arraylike(true);
  Array.prototype.fill.call(frozen, "foo", 5, 6);
  assertEquals("foo", frozen[5]);
  assertThrows(() => Array.prototype.fill.call(frozen, "foo"), TypeError);
}

// Array.prototype.shift
{
  const sealed = Object.seal({length: 0});
  assertEquals(undefined, Array.prototype.shift.call(sealed));
}{
  const sealed = Object.seal({length: 42});
  assertEquals(undefined, Array.prototype.shift.call(sealed));
}{
  let x;
  let obj = {length: 42, [1]: "foo"};
  Object.defineProperty(obj, 0, {get() {return x}, set(y) {x = y}});
  const sealed = Object.seal(obj);
  assertThrows(() => Array.prototype.shift.call(sealed), TypeError);
  assertEquals("foo", sealed[0]);
}{
  const frozen = Object.freeze({length: 0});
  assertThrows(() => Array.prototype.shift.call(frozen), TypeError);
}

// Array.prototype.splice
{
  const sealed = arraylike(false);
  assertEquals([undefined], Array.prototype.splice.call(sealed, 5, 1, "foo"));
  assertEquals("foo", sealed[5]);
  assertThrows(() => Array.prototype.splice.call(sealed, 5, 0, "bar"),
      TypeError);
  assertEquals("foo", sealed[5]);
}{
  const frozen = arraylike(true);
  assertThrows(() => Array.prototype.splice.call(frozen, 5, 1, "foo"),
      TypeError);
  assertEquals("foo", frozen[5]);
  assertThrows(() => Array.prototype.splice.call(frozen, 5, 0, "bar"),
      TypeError);
  assertEquals("foo", frozen[5]);
}