[postcss-is-pseudo-class] Cannot expand simple statements with complex selectors

[WRtux]

Bug description

I already know that complex selectors can cause problems, but I think the statement below is quite straightforward and can be expanded safely (currently, the complex selector is preserved). Is it possible to implement this feature, or is there an option to force to expand complex selectors?

Source CSS

:is(.frame, .frame> .wrapper)> .target {
  background-color: #ffc;
}

Expected CSS

.frame:not(.does-not-exist)> .target, .frame> .wrapper> .target {
  background-color: #ffc;
}

Actual CSS

:is(.frame> .wrapper)> .target {
  background-color: #ffc;
}
.frame:not(.does-not-exist)> .target {
  background-color: #ffc;
}

Does it happen with npx @csstools/csstools-cli <plugin-name> minimal-example.css?

N/A

Debug output

postcss-is-pseudo-class: ***.css:1:1: Complex selectors in ':is(.frame, .frame> .wrapper)> .dialog' can not be transformed to an equivalent selector without ':is()'.
postcss-is-pseudo-class: ***.css:1:1: Complex selectors in ':is(.frame> .wrapper)> .dialog' can not be transformed to an equivalent selector without ':is()'.

Extra config

None. Default config.

What plugin are you experiencing this issue on?

PostCSS Is Pseudo Class

Plugin version

2.0.7

What OS are you experiencing this on?

No response

Node Version

16.17.1

Validations

• Follow our Code of Conduct
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

Would you like to open a PR for this bug?

• I'm willing to open a PR

[romainmenke]

Thank you for requesting this @WRtux 🎉

A lot of patterns can be supported relatively easy, but we don't know which patterns are common, adding support for all of them proactively would be too much work :) So it's really helpful to get this feedback.

We've prepared a change that should resolve this : #923

[romainmenke]

@WRtux We have released this update.
Please let us know if something isn't working as expected 🙇