<!DOCTYPE html>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
customElements.define('custom-input', class extends HTMLElement {
  static get formAssociated() {return true;}
});
</script>

<form id="custom-form">
  <custom-input id="custom-1" name="alone"></custom-input>
  <custom-input id="custom-2" name="group"></custom-input>
  <custom-input id="custom-3" name="group"></custom-input>
  <custom-button id="custom-4" name="upgrade"></custom-button>
</form>
<custom-input id="custom-5" name="group" form="custom-form"></custom-input>
<custom-button id="custom-6" name="group" form="custom-form"></custom-button>

<script>
test(() => {
  const formElements = document.forms[0].elements;
  assert_equals(formElements['invalid'],undefined);
  assert_equals(formElements['alone'],document.getElementById('custom-1'),'Single input should be returned as-is');
  assert_true(formElements['group'] instanceof RadioNodeList,'Repeated names should result in RadioNodeList');
  const expected = [document.getElementById('custom-2'),
                    document.getElementById('custom-3'),
                    document.getElementById('custom-5')];
  assert_array_equals(formElements['group'],expected,'Repeated names should be contained in RadioNodeList, in tree order');
}, 'Form associated custom elements should work with document.forms.elements.namedItem()');

test(() => {
  const formElements = document.forms[0].elements;
  assert_equals(formElements['upgrade'],undefined);
  customElements.define('custom-button', class extends HTMLElement {
    static get formAssociated() {return true;}
  });
  assert_equals(formElements['upgrade'],document.getElementById('custom-4'),'Single button should be returned after upgrading');
  const expected = [document.getElementById('custom-2'),
                    document.getElementById('custom-3'),
                    document.getElementById('custom-5'),
                    document.getElementById('custom-6')];
  assert_array_equals(formElements['group'],expected,'Repeated names should be contained in RadioNodeList, in tree order after upgrading');
}, 'Form associated custom elements should work with document.forms.elements.namedItem() after upgrading');

test(() => {
  const formElements = document.forms[0].elements;
  assert_equals(formElements['alone'],document.getElementById('custom-1'),'Single input should be returned as-is');
  const expected = [document.getElementById('custom-2'),
                    document.getElementById('custom-3'),
                    document.getElementById('custom-5'),
                    document.getElementById('custom-6')];
  assert_array_equals(formElements['group'],expected,'Repeated names should be contained in RadioNodeList, in tree order after upgrading');
  document.getElementById('custom-1').setAttribute("name", "group");
  assert_equals(formElements['alone'],undefined);
  const expectedNew = [document.getElementById('custom-1'),
                      document.getElementById('custom-2'),
                      document.getElementById('custom-3'),
                      document.getElementById('custom-5'),
                      document.getElementById('custom-6')];
  assert_array_equals(formElements['group'],expectedNew,'Repeated names should be contained in RadioNodeList, in tree order after updating name attribute');
}, 'Form associated custom elements should work with document.forms.elements.namedItem() after updating the name attribute');

</script>
</body>
