4 <title>If element interface for name doesn't exists then error must be thrown</title>
5 <meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
6 <meta name="assert" content="If NAME was provided and is not null and if element interface for the name and namespace does not exist or is an interface for a custom element, set ERROR to InvalidName and stop">
7 <link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
8 <script src="../../../../resources/testharness.js"></script>
9 <script src="../../../../resources/testharnessreport.js"></script>
10 <script src="../testcommon.js"></script>
11 <link rel="stylesheet" href="../../../../resources/testharness.css">
17 var doc = newHTMLDocument();
18 doc.registerElement('x-a');
19 assert_throws('NotSupportedError', function() {
20 doc.registerElement('x-b', {extends: 'x-a'});
21 }, 'Exception should be thrown in case of attempt to register ' +
22 'a custom element which extends another custom element');
23 }, 'Exception should be thrown in case of attempt to register ' +
24 'a custom element which extends another custom element');