<!DOCTYPE html>
<script src="../resources/js-test.js"></script>
<body>
<script>
description('Tests basic web-exposure of Custom Elements');

function evalAndLogValue(s) {
  debug(evalAndLog(s));
  debug('');
}

evalAndLogValue('Document.prototype.hasOwnProperty("registerElement")');
evalAndLogValue('typeof Document.prototype.registerElement');
evalAndLogValue('document.createElement("x-a") instanceof HTMLUnknownElement');

var div = document.createElement('div');
div.innerHTML = '<div is="x-b">';
document.body.appendChild(div);
evalAndLogValue('document.querySelector(":unresolved")');
div.remove();

var span = document.createElement('span', 'type-extension');
evalAndLogValue('span.getAttribute("is")');

class A extends HTMLButtonElement {
  constructor() {
    super();
  }
}

if (shouldNotThrow('window.customElements.define("a-a", A, {extends: "b"})')) {
  if (window.internals) {
    shouldBeTrue(internals.runtimeFlags.customElementsBuiltinEnabled);
  }
}

successfullyParsed = true;
</script>