JSTests/test262/test/built-ins/TypedArray/prototype/lastIndexOf/get-length-uses-internal-arraylength.js

// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-%typedarray%.prototype.lastindexof
description: Get "length" uses internal ArrayLength
info: |
  22.2.3.17 %TypedArray%.prototype.lastIndexOf ( searchElement [ , fromIndex ] )

  %TypedArray%.prototype.lastIndexOf is a distinct function that implements the
  same algorithm as Array.prototype.lastIndexOf as defined in 22.1.3.15 except
  that the this object's [[ArrayLength]] internal slot is accessed in place of
  performing a [[Get]] of "length".

  22.1.3.15 Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] )

  ...
  2. Let len be ? ToLength(? Get(O, "length")).
  ...
includes: [testTypedArray.js]
features: [TypedArray]
---*/

Object.defineProperty(TypedArray.prototype, "length", {value: 0});

testWithTypedArrayConstructors(function(TA) {
  var sample = new TA([7]);

  Object.defineProperty(TA.prototype, "length", {value: 0});
  Object.defineProperty(sample, "length", {value: 0});

  assert.sameValue(sample.lastIndexOf(7), 0);
});