specify return type for querySelector

[YuichiNukiyama]

fix querySelector return type could be more specific for single-element selectors #8114

[mhegazy]

👍

[zhengbli]

Thanks @YuichiNukiyama !

[yuttie]

@YuichiNukiyama Thanks for your great work.

I found I cannot select an SVGTitleElement (https://developer.mozilla.org/en-US/docs/Web/API/SVGTitleElement) by querying "title" with SVGSVGElement's querySelector(). I think the problem is related to this PR.

I think it would be nice if querySelector("title") returns a value of type HTMLTitleElement | SVGTitleElement.

How do you think?

[YuichiNukiyama]

@yuttie
A good point. However, cast is necessary, so it is hard to use.