[samuil-banti-wpenigne]

Tailwind CSS v4 may contain square brackets in the class names i.e.

.\[\&
_\[data-piko-package\=review-card\]\]\:px-\[25px\] [data-piko-package=review-card]{pa
dding-inline:25px}

Other valid characters are also affected by the parser at this point:

{}[]~+"

So the goal of the PR is to enable parsing of such selectors.

[coveralls]

coverage: 75.471% (+0.04%) from 75.43% — samuil-banti-wpenigne:enable-escaped-symbols-in-the-class-names into MyIntervals:main

[Copilot]

🟡 Changes recommended

The escape helper repeatedly copies a growing array, introducing quadratic overhead for long compound selectors.

1 open issue

• Avoid end() to prevent quadratic selectorParts copying · New

What changed in this PR

This PR extends selector parsing to support escaped structural characters in class names, including Tailwind CSS v4 arbitrary variants.

Changes:

• Apply escape detection before interpreting brackets, parentheses, braces, and selector separators.
• Add regression tests for escaped characters, backslash parity, and selector boundaries.
• Document the parsing improvement in the changelog.

File	Description
tests/​Unit/​Property/​SelectorTest.php	Test escaped selectors and component boundaries.
tests/​Unit/​Property/​Selector/​CompoundSelectorTest.php	Test escaped structural characters and stop-character handling.
src/​Property/​Selector/​CompoundSelector.php	Extend escape detection across structural characters.
CHANGELOG.md	Record support for escaped selector characters.

_{Review effort: Balanced}

[JakeQZ]

Thanks @samuil-banti-wpenigne, this looks great, with excellent tests.

I've just spent several hours trying to decipher the CSS spec, which is as clear as mud (but more interesting than trying to patch up web servers ;)). Think I've got to the bottom of it. We're not handling the \r and \n cases correctly, as they cannot be escaped, but I think those should be left alone for now to be addressed in a future PR. Most other characters can be escaped and this change seems to address that very well.

I've made a couple of other minor suggested improvements.

[JakeQZ]

excellent tests.

Some may belong in the Functional rather than Unit division due to their dependency on other classes, but that can be tidied-up post-PR, as I think we have other misplaced tests.

[JakeQZ]

This LGTM now, thanks for contributing <3.

[JakeQZ]

@oliverklee, do you see any other issues?