Content - 1ed625f63bbb3025f8df7ae75e75b0c69ebc9a96 - a2dffb4/custom-elements/HTMLElement-constructor.html

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Tip revision: 617fbe23dc89c0e48f443e4d3a6e918d7bdc3022 authored by Anne van Kesteren on 28 September 2016, 13:24:58 UTC
WIP
Tip revision: 617fbe2
HTMLElement-constructor.html
<!DOCTYPE html>
<html>
<head>
<title>Custom Elements: HTMLElement must allow subclassing</title>
<meta name="author" title="Ryosuke Niwa" href="mailto:rniwa@webkit.org">
<meta name="assert" content="HTMLElement must allow subclassing">
<link rel="help" href="https://html.spec.whatwg.org/#html-element-constructors">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body>
<div id="log"></div>
<script>

test(function () {
    customElements.define('html-custom-element', HTMLElement);
    assert_throws({'name': 'TypeError'}, function () { new HTMLElement(); });
}, 'HTMLElement constructor must throw a TypeError when NewTarget is equal to itself');

test(function () {
    customElements.define('html-proxy-custom-element', new Proxy(HTMLElement, {}));
    assert_throws({'name': 'TypeError'}, function () { new HTMLElement(); });
}, 'HTMLElement constructor must throw a TypeError when NewTarget is equal to itself via a Proxy object');

test(function () {
    class SomeCustomElement extends HTMLElement {};
    assert_throws({'name': 'TypeError'}, function () { new SomeCustomElement; });
}, 'HTMLElement constructor must throw TypeError when it has not been defined by customElements.define');

test(function () {
    class CustomElementWithInferredTagName extends HTMLElement {};
    customElements.define('inferred-name', CustomElementWithInferredTagName);

    var instance = new CustomElementWithInferredTagName;
    assert_true(instance instanceof Element, 'A custom element must inherit from Element');
    assert_true(instance instanceof Node, 'A custom element must inherit from Node');
    assert_equals(instance.localName, 'inferred-name');
    assert_equals(instance.nodeName, 'INFERRED-NAME');
    assert_equals(instance.namespaceURI, 'http://www.w3.org/1999/xhtml', 'A custom HTML element must use HTML namespace');

    document.body.appendChild(instance);
    assert_equals(document.body.lastChild, instance,
        'document.body.appendChild must be able to insert a custom element');
    assert_equals(document.querySelector('inferred-name'), instance,
        'document.querySelector must be able to find a custom element by its tag name');

}, 'HTMLElement constructor must infer the tag name from the element interface');

test(function () {
    class ConcreteCustomElement extends HTMLElement { };
    class SubCustomElement extends ConcreteCustomElement { };
    customElements.define('concrete-custom-element', ConcreteCustomElement);
    customElements.define('sub-custom-element', SubCustomElement);

    var instance = new ConcreteCustomElement();
    assert_true(instance instanceof ConcreteCustomElement);
    assert_false(instance instanceof SubCustomElement);
    assert_equals(instance.localName, 'concrete-custom-element');
    assert_equals(instance.nodeName, 'CONCRETE-CUSTOM-ELEMENT');

    var instance = new SubCustomElement();
    assert_true(instance instanceof ConcreteCustomElement);
    assert_true(instance instanceof SubCustomElement);
    assert_equals(instance.localName, 'sub-custom-element');
    assert_equals(instance.nodeName, 'SUB-CUSTOM-ELEMENT');

}, 'HTMLElement constructor must allow subclassing a custom element');

test(function () {
    class AbstractCustomElement extends HTMLElement { };
    class ConcreteSubCustomElement extends AbstractCustomElement { };
    customElements.define('concrete-sub-custom-element', ConcreteSubCustomElement);

    var instance = new ConcreteSubCustomElement();
    assert_true(instance instanceof AbstractCustomElement);
    assert_true(instance instanceof ConcreteSubCustomElement);
    assert_equals(instance.localName, 'concrete-sub-custom-element');
    assert_equals(instance.nodeName, 'CONCRETE-SUB-CUSTOM-ELEMENT');

}, 'HTMLElement constructor must allow subclassing an user-defined subclass of HTMLElement');

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