@webcomponents/custom-elements
Version:
HTML Custom Elements Polyfill
53 lines (45 loc) • 1.94 kB
HTML
<title>Custom Elements: Custom Element State "Failed" in Upgrades</title>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="resources/custom-elements-helpers.js"></script>
<body>
<script>;
// Custom Element State
// https://dom.spec.whatwg.org/#concept-element-custom-element-state
test_with_window(w => {
let document = w.document;
let element = document.createElement('a-a');
let constructorCount = 0;
w.customElements.define('a-a', class extends w.HTMLElement {
constructor() {
constructorCount++;
throw new Error();
}
connectedCallback() {
// TODO(davaajav): remove the failure expectation when this issue is closed
// https://github.com/w3c/webcomponents/issues/563
assert_unreached('connectedCallback should not be invoked if constructor threw');
}
});
// Upgrade calls the constructor.
// 9. If constructResult is an abrupt completion, then
// Set element's custom element state to "failed".
// https://html.spec.whatwg.org/multipage/scripting.html#upgrades
let container = document.body;
container.appendChild(element);
assert_equals(constructorCount, 1, 'constructor should be invoked once');
// "failed" is not "defined"
// https://dom.spec.whatwg.org/#concept-element-defined
assert_false(element.matches(':defined'));
// "failed" element should implement HTMLUnknownElement only in "creating an element for a token"
// https://html.spec.whatwg.org/#create-an-element-for-the-token
assert_equals(Object.getPrototypeOf(element), w.HTMLElement.prototype);
// 2. If element's custom element state is "failed", then abort these steps.
// https://html.spec.whatwg.org/multipage/scripting.html#upgrades
container.appendChild(element);
assert_equals(constructorCount, 1, 'constructor should be invoked once');
});
</script>
</body>