test-codeowners

Measures getCodeOwnersForFilename, the per-test-file owner resolution Test Optimization runs across a suite: a reversed walk of the parsed CODEOWNERS entries testing each pattern's regex against the path until one matches. Entries come from the real parser reading a committed CODEOWNERS fixture under fixtures/<variant>/ — large is a snapshot of this repo's own .github/CODEOWNERS (anchored / extension / ** rules a big monorepo carries), small a typical small-library file — so the two variants bracket the reversed-walk cost on real files rather than synthesized ones. Each variant runs lookups over a corpus of paths shaped like that repo's files (matches at varying depths plus a full-scan miss); each pass uses a fresh cache view so every lookup is a real regex scan.