<!doctype html>
<meta charset=utf-8>
<link rel=help href=https://dom.spec.whatwg.org/#interface-htmlcollection>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>

<div id=log></div>

<!-- with no attribute -->
<span></span>

<!-- with `id` attribute -->
<span id=''></span>
<span id='some-id'></span>
<span id='some-id'></span><!-- to ensure no duplicates -->

<!-- with `name` attribute -->
<span name=''></span>
<span name='some-name'></span>
<span name='some-name'></span><!-- to ensure no duplicates -->

<!-- with `name` and `id` attribute -->
<span id='another-id' name='another-name'></span>

<script>
test(function () {
  var elements = document.getElementsByTagName("span");
  assert_array_equals(
    Object.getOwnPropertyNames(elements),
    ['0', '1', '2', '3', '4', '5', '6', '7', 'some-id', 'some-name', 'another-id', 'another-name']
  );
}, 'Object.getOwnPropertyNames on HTMLCollection');

test(function () {
  var elem = document.createElementNS('some-random-namespace', 'foo');
  this.add_cleanup(function () {elem.remove();});
  elem.setAttribute("name", "some-name");
  document.body.appendChild(elem);

  var elements = document.getElementsByTagName("foo");
  assert_array_equals(Object.getOwnPropertyNames(elements), ['0']);
}, 'Object.getOwnPropertyNames on HTMLCollection with non-HTML namespace');

test(function () {
  var elem = document.createElement('foo');
  this.add_cleanup(function () {elem.remove();});
  document.body.appendChild(elem);

  var elements = document.getElementsByTagName("foo");
  elements.someProperty = "some value";

  assert_array_equals(Object.getOwnPropertyNames(elements), ['0', 'someProperty']);
}, 'Object.getOwnPropertyNames on HTMLCollection with expando object');

test(function() {
  var elements = document.getElementsByTagName("span");
  var old_item = elements["some-id"];
  var old_desc = Object.getOwnPropertyDescriptor(elements, "some-id");
  assert_equals(old_desc.value, old_item);
  assert_false(old_desc.enumerable);
  assert_true(old_desc.configurable);
  assert_false(old_desc.writable);

  elements["some-id"] = 5;
  assert_equals(elements["some-id"], old_item);
  assert_throws_js(TypeError, function() {
    "use strict";
    elements["some-id"] = 5;
  });
  assert_throws_js(TypeError, function() {
    Object.defineProperty(elements, "some-id", { value: 5 });
  });

  delete elements["some-id"];
  assert_equals(elements["some-id"], old_item);

  assert_throws_js(TypeError, function() {
    "use strict";
    delete elements["some-id"];
  });
  assert_equals(elements["some-id"], old_item);

}, 'Trying to set an expando that would shadow an already-existing named property');

test(function() {
  var elements = document.getElementsByTagName("span");
  var old_item = elements["new-id"];
  var old_desc = Object.getOwnPropertyDescriptor(elements, "new-id");
  assert_equals(old_item, undefined);
  assert_equals(old_desc, undefined);

  elements["new-id"] = 5;
  assert_equals(elements["new-id"], 5);

  var span = document.createElement("span");
  this.add_cleanup(function () {span.remove();});
  span.id = "new-id";
  document.body.appendChild(span);

  assert_equals(elements.namedItem("new-id"), span);
  assert_equals(elements["new-id"], 5);

  delete elements["new-id"];
  assert_equals(elements["new-id"], span);
}, 'Trying to set an expando that shadows a named property that gets added later');

test(function() {
  var elements = document.getElementsByTagName("span");
  var old_item = elements["new-id2"];
  var old_desc = Object.getOwnPropertyDescriptor(elements, "new-id2");
  assert_equals(old_item, undefined);
  assert_equals(old_desc, undefined);

  Object.defineProperty(elements, "new-id2", { configurable: false, writable:
                                              false, value: 5 });
  assert_equals(elements["new-id2"], 5);

  var span = document.createElement("span");
  this.add_cleanup(function () {span.remove();});
  span.id = "new-id2";
  document.body.appendChild(span);

  assert_equals(elements.namedItem("new-id2"), span);
  assert_equals(elements["new-id2"], 5);

  delete elements["new-id2"];
  assert_equals(elements["new-id2"], 5);

  assert_throws_js(TypeError, function() {
    "use strict";
    delete elements["new-id2"];
  });
  assert_equals(elements["new-id2"], 5);
}, 'Trying to set a non-configurable expando that shadows a named property that gets added later');
</script>