the representation audit parses each file on its own, so a file that only compiles under cfg(test) because its parent declares it with #[cfg(all(test, ...))] mod interleaving; looked like production code. the stream interleaving tests' fixture helpers showed up as two missing codec boundaries even though nothing outside the tests ever runs them. discover now parses every file first, follows out-of-line mod declarations to the files they load, and scans a file as test-only when a test-only declaration (or a file that is itself test-only) loads it.