webidl/ecmascript-binding/default-iterator-object.html

<!doctype html>
<meta charset="utf-8">
<title>Default iterator objects</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
test(() => {
  const iterator1 = new URLSearchParams()[Symbol.iterator]();
  const iterator2 = new URLSearchParams().keys();
  const iterator3 = new URLSearchParams().values();
  const iterator4 = new URLSearchParams().entries();
  assert_equals(Object.getPrototypeOf(iterator1), Object.getPrototypeOf(iterator2));
  assert_equals(Object.getPrototypeOf(iterator1), Object.getPrototypeOf(iterator3));
  assert_equals(Object.getPrototypeOf(iterator1), Object.getPrototypeOf(iterator4));
}, "Default iterator objects for an interface have the same prototype");

test(() => {
  const iterator = new URLSearchParams().entries();
  assert_equals(Object.prototype.toString.call(iterator), "[object URLSearchParams Iterator]");
}, "Object.prototype.toString returns correct value");

test(() => {
  const iterator = new URLSearchParams().entries();
  assert_equals(iterator[Symbol.toStringTag], "URLSearchParams Iterator");
  assert_equals(Object.getOwnPropertyDescriptor(iterator, Symbol.toStringTag), undefined);
}, "@@toStringTag has correct value from prototype");
</script>