Closed Bug 1477023 Opened 6 years ago Closed 6 years ago

Some conditions disallowed in element creation phase are unexpectedly allowed if the element is a customized built-in element

Categories

(Core :: DOM: Core & HTML, defect)

Product:
Core
Component:
DOM: Core & HTML
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

()

Status:
RESOLVED INVALID
Tracking Flags:
Tracking Status
firefox63 --- affected

People

(Reporter: zjz, Unassigned)

References

Details

<!DOCTYPE html>
<meta charset="utf-8">
<title>Some conditions disallowed in element creation phase are unexpectedly allowed if the element is a customized built-in element</title>
<script>
customElements.define("test-case1", class extends HTMLElement
{
	constructor()
	{
		super();
		// Should not be allowed to have a child in this phase
		this.textContent = "Test case1: this text is not expected to be displayed";
		// Should not be allowed to have an attribute in this phase
		this.setAttribute("data-test", "test");

		// Upon returning, a "NotSupportedError" DOMException should be thrown
		// due to the two previous operations.
		//
		// Refer to Step 6.1.4 and 6.1.5 of creating an element at the spec:
		// https://dom.spec.whatwg.org/#concept-create-element
		//
		// Test result:
		// Both Firefox trunk and Chrome 67 follow the spec and throws a exception.
	}
});

customElements.define("test-case2", class extends HTMLDivElement
{
	constructor()
	{
		super();
		// Should not be allowed to have a child in this phase
		this.textContent = "Test case2: this text is not expected to be displayed";
		// Should not be allowed to have an attribute in this phase
		this.setAttribute("data-test", "test");

		// Upon returning, a "NotSupportedError" DOMException should be thrown
		// due to the two previous operations.
		//
		// Refer to Step 6.1.4 and 6.1.5 of creating an element at the spec:
		// https://dom.spec.whatwg.org/#concept-create-element
		//
		// Test result:
		// Firefox trunk fails to follow the spec, no expcetion is thrown.
		// Chrome 67 follows the spec and throws a exception.
	}
}, {extends: "div"});
</script>

<div is="test-case2"></div>
<test-case1></test-case1>
Blocks: 1358989
(In reply to 張俊芝(Zhang Junzhi) from comment #0) 
> customElements.define("test-case2", class extends HTMLDivElement
> {
> 	constructor()
> 	{
> 		super();
> 		// Should not be allowed to have a child in this phase
> 		this.textContent = "Test case2: this text is not expected to be displayed";
> 		// Should not be allowed to have an attribute in this phase
> 		this.setAttribute("data-test", "test");
> 
> 		// Upon returning, a "NotSupportedError" DOMException should be thrown
> 		// due to the two previous operations.
> 		//
> 		// Refer to Step 6.1.4 and 6.1.5 of creating an element at the spec:
> 		// https://dom.spec.whatwg.org/#concept-create-element
> 		//
> 		// Test result:
> 		// Firefox trunk fails to follow the spec, no expcetion is thrown.
> 		// Chrome 67 follows the spec and throws a exception.
> 	}
> }, {extends: "div"});
> </script>
> 
> <div is="test-case2"></div>

If I interpret the spec correctly, the built-in element case should refer to step 5 of https://dom.spec.whatwg.org/#concept-create-element, which runs upgrade steps [1] and allow to have an attribute and a child. Look like we do follow the spec, though I am not sure if the spec intent to have inconsistent behavior or it is a spec issue.

[1] https://html.spec.whatwg.org/multipage/custom-elements.html#concept-upgrade-an-element
Yeah, we follow the spec. Reporter, if you want to change the spec to be more consistent, please file a spec bug.

As of now, this looks invalid.
Status: NEW → RESOLVED
Closed: 6 years ago
Resolution: --- → INVALID
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