| <!DOCTYPE html> |
| <title>Shadow DOM: Attaching a ShadowRoot for custom elements</title> |
| <meta name="author" title="Hayato Ito" href="mailto:hayato@chromium.org"> |
| <link rel="help" href="https://dom.spec.whatwg.org/#dom-element-attachshadow"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script> |
| class MyAutonomousCustomElement extends HTMLElement { |
| } |
| |
| customElements.define('my-custom', MyAutonomousCustomElement); |
| |
| test(() => { |
| assert_true(document.createElement('my-custom').attachShadow({mode: "open"}) instanceof ShadowRoot); |
| }, 'Element.attachShadow must create an instance of ShadowRoot for autonomous custom elements'); |
| |
| class MyCustomizedBuiltinElement extends HTMLInputElement { |
| } |
| |
| customElements.define('my-input', MyCustomizedBuiltinElement, { extends: 'input' }); |
| |
| test(() => { |
| assert_throws({'name': 'NotSupportedError'}, () => { |
| document.createElement('input', {is: 'my-input'}).attachShadow({mode: "open"}); |
| }); |
| }, 'Element.attachShadow must throw a NotSupportedError for customized built-in elements'); |
| </script> |
| </body> |
| </html> |
