Replace `select().closest()` calls with `:has`

The :has() CSS selector is nowhere to be seen yet and given the recent de-class-ification of GitHub’s DOM we found ourself needing code like this very often:

select('.some-octicon').closest('details')

"Custom API" suggestion, discarded. Sizzle is best

so I wonder how we can “polyfill” the selector without have to load Sizzle. Example:

select2('details').has('.some-octicon')

Example:

function select2(selector: string) {
	return {
		has(children: string) {
			return select(children)?.closest(selector);
		}
	}
}

select2.all = (selector: string) => {
	return {
		has(children: string) {
			return select.all(children) :filter/map: .closest(selector);
		}
	}
}

Thoughts? Worth it at all?

[fregante]

5% of our users have it. 95% more to go.

[fregante]

The advantage of just using sizzle is that we can drop it easily once :has() becomes available in every browser (2028)