[selectors-4] Is current spec for `:empty` web compatible?

[nt1m]

https://w3c.github.io/csswg-drafts/selectors-4/#the-empty-pseudo

:empty now matches whitespace-only nodes, this is not implemented in any browser yet, and there are concerns that implementing this may not be web compatible.

Should the spec be changed to match current implementations?

[SebastianZ]

The question is rather whether this claim from the spec. is true:

Note: In Level 2 and Level 3 of Selectors, :empty did not match elements that contained only white space. This was changed so that that — given white space is largely collapsible in HTML and is therefore used for source code formatting, and especially because elements with omitted end tags are likely to absorb such white space into their DOM text contents — elements which authors perceive of as empty can be selected by this selector, as they expect.

So, to answer whether this change in the behavior of :empty is actually web compatible, the HTTP archive should be queried if that didn't happen yet.

Sebastian

[gsnedders]

There's a lot of discussion in #1967 about this question. (I don't know if it's worthwhile having a separate issue to track this?)