Function _check_build_file_naming

ci/lint_cpp/test_unity_build.py:854–894

Validate that every .cpp file in src/fl/build/ follows the naming convention and maps to a valid directory. Returns: list of violation strings

(src_dir: Path)

def _check_build_file_naming(src_dir: Path) -> list[str]:
    """
    Validate that every .cpp file in src/fl/build/ follows the naming convention
    and maps to a valid directory.

    Returns:
        list of violation strings
    """
    violations: list[str] = []
    build_dir = src_dir / "fl" / "build"
    if not build_dir.exists():
        violations.append("Missing build directory: src/fl/build/")
        return violations

    actual_files = {f.name for f in build_dir.glob("*.cpp")}
    expected_files = {f.split("/")[-1] for f in EXPECTED_BUILD_FILES}

    # Check for unexpected files
    unexpected = actual_files - expected_files
    for f in sorted(unexpected):
        violations.append(
            f"src/fl/build/{f}: Unexpected build file. "
            f"Not in EXPECTED_BUILD_FILES list."
        )

    # Check for missing files
    missing = expected_files - actual_files
    for f in sorted(missing):
        violations.append(f"src/fl/build/{f}: Expected build file is missing.")

    # Validate each file maps to a valid directory
    for build_file in sorted(build_dir.glob("*.cpp")):
        dir_path, _ = _parse_build_filename(build_file.name)
        mapped_dir = src_dir / dir_path if dir_path else src_dir
        if not mapped_dir.exists():
            rel_file = build_file.relative_to(PROJECT_ROOT).as_posix()
            violations.append(
                f"{rel_file}: Maps to non-existent directory '{dir_path or 'src/'}'."
            )

    return violations


def _check_no_orphan_cpp_files(src_dir: Path) -> list[str]: