custom-elements/Document-createElement-customized-builtins.html

<!DOCTYPE html>
<html>
<head>
<title>Custom Elements: document.createElement should create a customized builtin element with synchronous custom elements flag set</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/custom-elements-helpers.js"></script>
</head>
<body>
<div id="log"></div>
<script>
setup({allow_uncaught_exception:true});

function assert_reports(expected, testFunction, message) {
    var uncaughtError = null;
    window.onerror = function (message, url, lineNumber, columnNumber, error) { uncaughtError = error; return true; }
    testFunction();
    if (typeof(expected) == 'string')
        assert_equals(uncaughtError, expected, message);
    else if (expected && 'name' in expected)
        assert_equals(uncaughtError.name, expected.name, message);
    else
      assert_equals(uncaughtError, expected, message);
    window.onerror = null;
}

test(function () {
    class AutonomousCustomElement extends HTMLElement {};
    class IsCustomElement extends HTMLElement {};

    customElements.define('autonomous-custom-element', AutonomousCustomElement);
    customElements.define('is-custom-element', IsCustomElement);

    var instance = document.createElement('autonomous-custom-element', { is: 'is-custom-element'});

    assert_true(instance instanceof AutonomousCustomElement);
    assert_equals(instance.localName, 'autonomous-custom-element');
    assert_equals(instance.namespaceURI, 'http://www.w3.org/1999/xhtml', 'A custom element HTML must use HTML namespace');

    var instance2 = document.createElement('undefined-element', { is: 'is-custom-element'});
    assert_false(instance2.matches(':defined'));
    class DefinedLater extends HTMLElement {}
    customElements.define('undefined-element', DefinedLater);
    document.body.appendChild(instance2);
    assert_true(instance2 instanceof DefinedLater);
}, 'document.createElement must create an instance of autonomous custom elements when it has is attribute');

test(() => {
    class SuperP extends HTMLParagraphElement {}
    customElements.define("super-p", SuperP, { extends: "p" });

    const superP = document.createElement("p", { is: "super-p" });
    assert_true(superP instanceof HTMLParagraphElement);
    assert_true(superP instanceof SuperP);
    assert_equals(superP.localName, "p");

    const notSuperP = document.createElement("p", "super-p");
    assert_true(notSuperP instanceof HTMLParagraphElement);
    assert_false(notSuperP instanceof SuperP);
    assert_equals(notSuperP.localName, "p");
}, "document.createElement()'s second argument is to be ignored when it's a string");

test(function () {
    var exceptionToThrow = {name: 'exception thrown by a custom constructor'};
    class ThrowCustomBuiltinElement extends HTMLDivElement {
        constructor()
        {
            super();
            if (exceptionToThrow)
                throw exceptionToThrow;
        }
    };
    customElements.define('throw-custom-builtin-element', ThrowCustomBuiltinElement, { extends: 'div' });

    assert_throws_exactly(exceptionToThrow, function () { new ThrowCustomBuiltinElement; });
    var instance;
    assert_reports(exceptionToThrow, function () { instance = document.createElement('div', { is: 'throw-custom-builtin-element' }); });
    assert_equals(instance.localName, 'div');
    assert_true(instance instanceof HTMLDivElement);

    exceptionToThrow = false;
    var instance = document.createElement('div', { is: 'throw-custom-builtin-element' });
    assert_true(instance instanceof ThrowCustomBuiltinElement);
    assert_equals(instance.localName, 'div');

}, 'document.createElement must report an exception thrown by a custom built-in element constructor');

test(() => {
  class MyElement extends HTMLDivElement {}

  // createElement with unknown 'is' should not throw.
  // https://github.com/w3c/webcomponents/issues/608
  let div = document.createElement('div', { is: 'my-div' });
  assert_false(div instanceof MyElement);
  assert_false(div.hasAttribute('is'));

  customElements.define('my-div', MyElement, { extends: 'div' });
  document.body.appendChild(div);
  assert_true(div instanceof MyElement, 'Undefined element is upgraded on connecting to a document');
}, 'document.createElement with unknown "is" value should create "undefined" state element');

</script>
</body>
</html>