<!DOCTYPE html>
<body>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<div id="container"></div>
<script>
test(() => {
  class MyElement1 extends HTMLElement {
  }
  customElements.define('my-element1', MyElement1);
  const container = document.querySelector('#container');

  let element = new MyElement1();
  assert_true(element.attachInternals() instanceof ElementInternals,
              'New - 1st call');
  assert_throws('InvalidStateError', () => { element.attachInternals(); },
                'New - 2nd call');

  element = document.createElement('my-element1');
  assert_true(element.attachInternals() instanceof ElementInternals,
              'createElement - 1st call');
  assert_throws('InvalidStateError', () => { element.attachInternals(); },
                'createElement - 2nd call');

  container.innerHTML = '<my-element1></my-element1>';
  assert_true(container.firstChild.attachInternals() instanceof ElementInternals,
              'Parser - 1st call');
  assert_throws('InvalidStateError', () => {
    container.firstChild.attachInternals();
  }, 'Parser - 2nd call');
}, 'Successful attachInternals() and the second call.');

test(() => {
  const builtin = document.createElement('div');
  assert_throws('InvalidStateError', () => { builtin.attachInternals() });

  const undefinedCustom = document.createElement('my-element');
  assert_throws('InvalidStateError', () => { undefinedCustom.attachInternals() });
}, 'If a custom element definition for the local name of the element doesn\'t' +
     ' exist, throw an InvalidStateError');

test(() => {
  class MyElement2 extends HTMLElement {
    static get disabledFeatures() { return ['internals']; }
  }
  customElements.define('my-element2', MyElement2);
  const container = document.querySelector('#container');

  assert_throws('InvalidStateError', () => {
    (new MyElement2).attachInternals();
  });
  assert_throws('InvalidStateError', () => {
    document.createElement('my-element2').attachInternals();
  });
  assert_throws('InvalidStateError', () => {
    container.innerHTML = '<my-element2></my-element2>';
    container.firstChild.attachInternals();
  });
}, 'If a custom element definition for the local name of the element has ' +
     'disable internals flag, throw an InvalidStateError');
</script>
</body>