JSTests/test262/test/built-ins/TypedArray/prototype/toLocaleString/calls-tostring-from-each-value.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.tolocalestring
description: >
  Calls toString from each property's value return from toLocaleString 
info: |
  22.2.3.28 %TypedArray%.prototype.toLocaleString ([ reserved1 [ , reserved2 ] ])

  %TypedArray%.prototype.toLocaleString is a distinct function that implements
  the same algorithm as Array.prototype.toLocaleString as defined in 22.1.3.27
  except that the this object's [[ArrayLength]] internal slot is accessed in
  place of performing a [[Get]] of "length".
  
  22.1.3.27 Array.prototype.toLocaleString ( [ reserved1 [ , reserved2 ] ] )
  
  ...
  5. Let firstElement be ? Get(array, "0").
  6. If firstElement is undefined or null, then
    a. Let R be the empty String.
  7. Else,
    a. Let R be ? ToString(? Invoke(firstElement, "toLocaleString")).
  8. Let k be 1.
  9.Repeat, while k < len
    a. Let S be a String value produced by concatenating R and separator.
    b. Let nextElement be ? Get(array, ! ToString(k)).
    c. If nextElement is undefined or null, then
      i. Let R be the empty String.
    d. Else,
      i. Let R be ? ToString(? Invoke(nextElement, "toLocaleString")).
includes: [testTypedArray.js]
features: [TypedArray]
---*/

var separator = ["", ""].toLocaleString();
var calls;

Number.prototype.toLocaleString = function() {
  return {
    toString: function() {
      calls++;
      return "hacks" + calls;
    },
    valueOf: function() {
      throw new Test262Error("should not call valueOf if toString is present");
    }
  };
};

var arr = [42, 0];
var expected = ["hacks1", "hacks2"].join(separator);

testWithTypedArrayConstructors(function(TA, N) {
  var sample = new TA(arr);
  calls = 0;
  assert.sameValue(sample.toLocaleString(), expected, "returns expected value");
  assert.sameValue(calls, 2, "toString called once for each item");
});