JSTests/test262/test/built-ins/TypedArray/prototype/sort/sort-tonumber.js

// Copyright (C) 2018 Mozilla Corporation. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-%typedarray%.prototype.sort
description: The result of compareFn is immediately passed through ToNumber
info: |
  22.2.3.26 %TypedArray%.prototype.sort ( comparefn )

  ...
  2. If comparefn is not undefined, then
    a. Let v be ? ToNumber(? Call(comparefn, undefined, « x, y »)).
    b. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
    ...
  ...
includes: [testTypedArray.js, detachArrayBuffer.js]
features: [TypedArray]
---*/

testWithTypedArrayConstructors(function(TA) {
  var ta = new TA(4);
  var ab = ta.buffer;

  var called = false;
  assert.throws(TypeError, function() {
    ta.sort(function(a, b) {
      // IsDetachedBuffer is checked right after calling comparefn.
      // So, detach the ArrayBuffer to cause sort to throw, to make sure we're actually calling ToNumber immediately (as spec'd)
      // (a possible bug is to wait until the result is inspected to call ToNumber, rather than immediately)
      $DETACHBUFFER(ab);
      return {
        [Symbol.toPrimitive]() { called = true; }
      };
    });
  });

  assert.sameValue(true, called);
});