A testability audit of the ignore span found the original comment overclaimed
("none of it can execute on Linux") and credited the wrong test file. Reality,
verified fragment by fragment:
- The span is excluded at FILE granularity but is not 100% syscall — _Coord /
_StartupInfoExW struct packing and write()'s empty-guard are pure transforms
that could be unit-tested on Linux if extracted from the binding-touching
methods. Tracked in T-431 (also covers the mirror gap in native_pty.dart's
POSIX marshalling).
- The pure helpers are tested by windows_pty_args_test.dart (not _test.dart).
- The FFI path's BEHAVIOUR is validated on windows-latest (real ConPTY spawn),
but windows.yml collects no coverage — so there is intentionally no line-
coverage metric for this span anywhere; correctness rests on that functional
suite + the VM soak, not on coverage.
Comment-only; no code or coverage change.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>