test_discover_floors.py

#!/usr/bin/env python3
# FLOOR
"""test_discover_floors.py - deterministic red floor for discover_floors.py.

Proves the discovery's teeth on built-in fixtures, one RED case per decidable
rule (METHOD §2; the "every checker ships its complete red floor" discipline):

  - marked file in the head window  -> discovered
  - unmarked file (a tool)          -> not discovered
  - marker past the scan window      -> not discovered (the bound bites)
  - marked file inside an excluded   -> not discovered (.venv exclusion bites)

Exit 0 = every behaviour holds; exit 1 = a regression. It carries the ``# FLOOR``
marker itself, so the discoverer finds and runs it like any other floor.
"""

from __future__ import annotations

import sys
import tempfile
from pathlib import Path

import discover_floors as df

MARKED = "#!/usr/bin/env python3\n# FLOOR\nx = 1\n"
UNMARKED = "#!/usr/bin/env python3\n# a tool, not a floor\nx = 1\n"
DEEP = "#\n#\n#\n#\n#\n# FLOOR\nx = 1\n"  # marker on line 6, past the window


def _write(base: Path, rel: str, text: str) -> Path:
    target = base / rel
    target.parent.mkdir(parents=True, exist_ok=True)
    target.write_text(text, encoding="utf-8")
    return target


def main() -> int:
    failures: list[str] = []
    with tempfile.TemporaryDirectory() as tmp:
        root = Path(tmp)
        marked = _write(root, "pkg/floor_marked.py", MARKED)
        _write(root, "pkg/tool_unmarked.py", UNMARKED)
        _write(root, "pkg/floor_deep.py", DEEP)
        _write(root, ".venv/lib/floor_hidden.py", MARKED)

        found = set(df.discover(root))

        checks = [
            ("marked file discovered", marked in found),
            (
                "unmarked tool ignored",
                (root / "pkg/tool_unmarked.py") not in found,
            ),
            (
                "marker past window ignored",
                (root / "pkg/floor_deep.py") not in found,
            ),
            (
                "excluded .venv ignored",
                (root / ".venv/lib/floor_hidden.py") not in found,
            ),
            ("exactly one floor found", found == {marked}),
            ("is_floor true on marked", df.is_floor(marked) is True),
            (
                "is_floor false on unmarked",
                df.is_floor(root / "pkg/tool_unmarked.py") is False,
            ),
        ]

    for label, ok in checks:
        status = "ok  " if ok else "FAIL"
        print(f"[{status}] {label}")
        if not ok:
            failures.append(label)

    if failures:
        print(f"\nFAIL: {len(failures)} check(s) regressed.")
        return 1
    print(f"\nOK: {len(checks)} checks passed.")
    return 0


if __name__ == "__main__":
    sys.exit(main())