<!DOCTYPE html>
<title>Shadow DOM: Attaching a ShadowRoot for custom elements</title>
<meta name="author" title="Hayato Ito" href="mailto:[email protected]">
<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');
test(() => {
assert_true(document.createElement('undefined-custom').attachShadow({mode: 'open'}) instanceof ShadowRoot);
}, 'Element.attachShadow must create an instance of ShadowRoot for undefined autonomous custom elements');
test(() => {
class ShadowDisabledElement extends HTMLElement {
static get disabledFeatures() { return ['shadow']; }
}
// No definition. attachShadow() should succeed.
let element = document.createElement('shadow-disabled-element');
element.attachShadow({mode: 'closed'});
// No definition and it's already a host.
assert_throws_dom('NotSupportedError', () => {
element.attachShadow({mode: 'closed'});
}, 'No definition, host');
// The element has a definition, and it's already a host.
customElements.define('shadow-disabled-element', ShadowDisabledElement);
assert_throws_dom('NotSupportedError', () => {
element.attachShadow({mode: 'closed'});
}, 'Definition, host');
// The element has a definition, and it's not a host.
assert_throws_dom('NotSupportedError', () => {
document.createElement('shadow-disabled-element').attachShadow({mode: 'closed'});
}, 'Definition, not a host');
}, 'Element.attachShadow for an autonomous custom element with ' +
'disabledFeatures=["shadow"] should throw a NotSupportedError');
test(() => {
class ShadowDisabledHeadingElement extends HTMLHeadingElement {
static get disabledFeatures() { return ['shadow']; }
}
// No definition. attachShadow() should succeed.
let element = document.createElement('h2',
{is: 'shadow-disabled-heading-element'});
element.attachShadow({mode: 'closed'});
// No definition and it's already a host.
assert_throws_dom('NotSupportedError', () => {
element.attachShadow({mode: 'closed'});
}, 'No definition, host.');
// The element has a definition, and it's already a host.
customElements.define('shadow-disabled-heading-element',
ShadowDisabledHeadingElement, {extends: 'h2'});
assert_throws_dom('NotSupportedError', () => {
element.attachShadow({mode: 'closed'});
}, 'Definition, host');
// The element has a definition, and it's not a host.
let h2 = document.createElement('h2', {is: 'shadow-disabled-heading-element'});
assert_throws_dom('NotSupportedError', () => {
h2.attachShadow({mode: 'closed'});
}, 'Definition, not a host');
}, 'Element.attachShadow for a customized built-in element with ' +
'disabledFeatures=["shadow"] should throw a NotSupportedError');
test(() => {
class CapitalShadowDisabledElement extends HTMLElement {
static get disabledFeatures() { return ['SHADOW']; }
}
customElements.define('capital-shadow-disabled-element', CapitalShadowDisabledElement);
// Test fails if this throws
document.createElement('capital-shadow-disabled-element').attachShadow({mode: 'open'});
}, 'Element.attachShadow for a custom element with disabledFeatures=["SHADOW"] should not throw a NotSupportedError');
class MyCustomizedBuiltinElement extends HTMLInputElement {
}
customElements.define('my-input', MyCustomizedBuiltinElement, { extends: 'input' });
test(() => {
assert_throws_dom('NotSupportedError', () => {
document.createElement('input', {is: 'my-input'}).attachShadow({mode: "open"});
});
}, 'Element.attachShadow must throw a NotSupportedError for customized built-in elements');
</script>
</body>
</html>