import db.scenario_defs as defs


def test_lock_check_returns_none_when_db_connection_missing(monkeypatch):
    monkeypatch.setattr(defs, "get_conn", lambda: None)

    result = defs.lock_check("cid", "test")

    assert result is None


def test_lock_check_returns_none_on_db_exception(monkeypatch):
    class BrokenCursor:
        def execute(self, *args, **kwargs):
            raise RuntimeError("db broken")

        def close(self):
            return None

    class BrokenConn:
        def cursor(self):
            return BrokenCursor()

    put_calls = {"n": 0}

    monkeypatch.setattr(defs, "get_conn", lambda: BrokenConn())
    monkeypatch.setattr(defs, "put_conn", lambda _c: put_calls.__setitem__("n", put_calls["n"] + 1))

    result = defs.lock_check("cid", "test")

    assert result is None
    assert put_calls["n"] == 1