Function check_test_result_cached

ci/meson/cache_utils.py:329–373

Check if the test result is cached and the test can be skipped. Returns True if: 1. A cache entry exists for this test name 2. The artifact (DLL/exe) exists at the saved path 3. The artifact mtime matches the cached value (+-0.001s) 4. The last result was "pass" Rationale f

(
    build_dir: Path, test_name: str, artifact_path: Path
)

def check_test_result_cached(
    build_dir: Path, test_name: str, artifact_path: Path
) -> bool:
    """Check if the test result is cached and the test can be skipped.

    Returns True if:
    1. A cache entry exists for this test name
    2. The artifact (DLL/exe) exists at the saved path
    3. The artifact mtime matches the cached value (+-0.001s)
    4. The last result was "pass"

    Rationale for DLL mtime as the sole gate:
    - src/ changes -> libfastled.a rebuilt (ar_content_preserving) -> DLL relinked -> mtime changes
    - test source changes -> DLL recompiled + relinked -> mtime changes
    - meson reconfiguration -> DLL rebuilt -> mtime changes
    Any code change that would affect test behavior also changes the DLL mtime.

    Overhead: ~3ms (one JSON read + one stat call). Savings: ~2s per cached run.
    """
    cache_file = _get_test_result_cache_file(build_dir)
    if not cache_file.exists():
        return False
    if not artifact_path.exists():
        return False

    try:
        with open(cache_file, "r", encoding="utf-8") as f:
            cache = json.load(f)

        entry = cache.get(test_name)
        if not entry:
            return False

        if entry.get("result") != "pass":
            return False

        saved_mtime = entry.get("artifact_mtime", -1.0)
        current_mtime = artifact_path.stat().st_mtime
        if abs(current_mtime - saved_mtime) > 0.001:
            return False

        return True

    except (OSError, json.JSONDecodeError, KeyError, TypeError, ValueError):
        return False


def save_test_result_state(