custom-elements/registries/ShadowRoot-init-customElementRegistry.html

<!DOCTYPE html>
<html>
<head>
<meta name="author" title="Ryosuke Niwa" href="mailto:rniwa@webkit.org">
<link rel="help" href="https://github.com/whatwg/html/issues/10854">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body>
<script>

test(() => {
    const shadowRoot = document.createElement('div').attachShadow({mode: 'closed'});
    assert_equals(shadowRoot.customElementRegistry, window.customElements);
}, 'A newly attached disconnected ShadowRoot should use the global registry by default');

test(() => {
    const host = document.body.appendChild(document.createElement('div'));
    const shadowRoot = host.attachShadow({mode: 'closed'});
    assert_equals(shadowRoot.customElementRegistry, window.customElements);
}, 'A newly attached connected ShadowRoot should use the global registry by default');

test(() => {
    const registry = new CustomElementRegistry;
    const shadowRoot = document.createElement('div').attachShadow({mode: 'closed', customElementRegistry: registry});
    assert_equals(shadowRoot.customElementRegistry, registry);
}, 'A newly attached disconnected ShadowRoot should use the scoped registry if explicitly specified in attachShadow');

test(() => {
    const registry = new CustomElementRegistry;
    const host = document.body.appendChild(document.createElement('div'));
    const shadowRoot = host.attachShadow({mode: 'closed', customElementRegistry: registry});
    assert_equals(shadowRoot.customElementRegistry, registry);
}, 'A newly attached connected ShadowRoot should use the scoped registry if explicitly specified in attachShadow');

test(() => {
    const host = document.body.appendChild(document.createElement('div'));
    assert_throws_js(TypeError, () => host.attachShadow({mode: 'closed', customElementRegistry: null}))
}, 'attachShadow() should throw for a null customElementRegistry value');

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