JSTests/test262/test/built-ins/TypedArrayConstructors/ctors/typedarray-arg/same-ctor-buffer-ctor-species-custom.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-typedarray
description: >
  Use default ArrayBuffer constructor on undefined buffer.constructor.@@species
info: |
  22.2.4.3 TypedArray ( typedArray )

  This description applies only if the TypedArray function is called with at
  least one argument and the Type of the first argument is Object and that
  object has a [[TypedArrayName]] internal slot.

  ...
  17. If SameValue(elementType, srcType) is true, then
    a. Let data be ? CloneArrayBuffer(srcData, srcByteOffset).
  ...

  24.1.1.4 CloneArrayBuffer ( srcBuffer, srcByteOffset [ , cloneConstructor ] )

  ...
  2. If cloneConstructor is not present, then
    a. Let cloneConstructor be ? SpeciesConstructor(srcBuffer, %ArrayBuffer%).
  ...

  7.3.20 SpeciesConstructor ( O, defaultConstructor )

  ...
  5. Let S be ? Get(C, @@species).
  6. If S is either undefined or null, return defaultConstructor.
  7. If IsConstructor(S) is true, return S.
  ...

  24.1.1.4 CloneArrayBuffer ( srcBuffer, srcByteOffset [ , cloneConstructor ] )

  ...
  8. Let targetBuffer be ? AllocateArrayBuffer(cloneConstructor, cloneLength).
  ...
includes: [testTypedArray.js]
features: [Symbol.species, TypedArray]
---*/

testWithTypedArrayConstructors(function(TA) {
  var sample = new TA();
  var ctor = {};
  var called = 0;
  var custom = {};

  sample.buffer.constructor = ctor;

  ctor[Symbol.species] = function() {
    called++;
  };

  ctor[Symbol.species].prototype = custom;

  var typedArray = new TA(sample);
  assert.sameValue(Object.getPrototypeOf(typedArray.buffer), custom);
  assert.sameValue(called, 0);
});