fix(publisher): read :not() and :is() correctly when tree-shaking class rules

[tommy230]

Summary

A rule that mentions a class only inside :not(), or as one alternative of :is()/:where(), is dropped at publish when that class is not in use on the site. The stylesheet reads back correctly and the canvas renders it; only the live site loses the styling.

A theme pads every nav link with

.nav > li > a:not(.cart-button) { padding: 0 20px }

No node on the site carries .cart-button, so publish drops the rule and every nav link sits flush against the next. Likewise :is(.a, .b) p is read as .a.b p and is dropped when only .b is in use.

The cause is in the tree shake of the class registry, which drops an ambient rule when its selector names a registry class that no node uses. selectorPartCanMatch in src/core/publisher/styleRuleTreeShake.ts scans the whole selector part with extractCssSelectorClasses and fails on any known-but-unused class, so it reads a negated class as a requirement and :is() alternatives as all required at once. CssSelectorClassToken.functionalDepth is not enough to fix it: depth cannot tell :not(.x) (never required) from :has(.x) or :nth-child(n of .x) (required), so the pseudo name has to be read.

The fix:

• Split each selector-list part into the text whose classes are all required and the :is()/:where() groups where one alternative is enough. :not(...) is removed outright, at any nesting. Quoted strings, attribute selectors and escapes are respected.
• :has() and :nth-child(n of ...) arguments stay required. Malformed pseudos (unbalanced parens, empty :is()) fall to "keep".

For any selector the shared class lexer reads correctly, this only keeps more CSS than before, never less. A part is dead only if a known-unused class remains in the required text or every alternative of some :is() group is dead, and both of those were already grounds for dropping under the old whole-part scan.

The one exception is an escaped quote in an unquoted attribute value inside a removed pseudo, such as .nav a:not([title=Don\'t]) .gone. The old scan read the \' as an opening quote, went blind for the rest of the selector and kept the rule by accident; the new scan reads past it and drops the rule, which is correct.

Verification

• bun run build
• bun run lint
• bun test: 7060 pass, 0 fail
• Docker/deployment check, if relevant: not relevant

New tests in src/__tests__/publisher/styleRuleTreeShake.test.ts: 3 of 7 fail on main and pass with this change.

Checklist

• Tests cover behavior changes.
• Docs were updated when behavior, config, deployment, or public surfaces changed. (docs/features/publisher.md.)
• No compatibility shim was added for old pre-release behavior.
• No secrets, local databases, uploads, or generated artifacts are included.

🤖 Generated with Claude Code