third_party/web_platform_tests/custom-elements/registering-custom-elements/element-registration-algorithm-no-registry.html

<!DOCTYPE html>
<html>
<head>
<title>If document has no registry NotSupportedError is thrown</title>
<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
<meta name="assert" content="If REGISTRY does not exist, set ERROR to NoRegistry and stop.">
<link rel="help" href="http://www.w3.org/TR/custom-elements/#dfn-element-registration-algorithm">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../testcommon.js"></script>
<link rel="stylesheet" href="/resources/testharness.css">
</head>
<body>
<div id="log"></div>
<script>
test(function() {
    var doc = document.implementation.createDocument(null, 'test', null);
    assert_throws('NotSupportedError', function(){
                      doc.registerElement('x-a');
                  }, 'Registering valid custom element in document ' +
                      'without registry should throw NotSupportedError');

}, 'Registering valid custom element without options in document ' +
    'without registry should throw NotSupportedError');


test(function() {
    var doc = document.implementation.createDocument(null, 'test', null);
    var proto = Object.create(HTMLElement.prototype);

    assert_throws('NotSupportedError', function(){
                      doc.registerElement('x-b', { prototype: proto, extends: 'a'});
                  }, 'Registering valid custom element in document ' +
                      'without registry should throw NotSupportedError');

}, 'Registering valid custom element with options in document ' +
    'without registry should throw NotSupportedError');
</script>
</body>
</html>