🐛 fix(lease): reject a duration no marker can carry (#723)

Co-authored-by: Bernát Gábor <gaborjbernat@gmail.com>

Author: lprnmns

docs/changelog/723.bugfix.rst

@@ -0,0 +1,2 @@
+``SoftFileLease`` and ``AsyncSoftFileLease`` now reject a boolean or non-finite ``lease_duration``, which used to
+publish an owner record their own ``owner`` property reads back as malformed.

src/filelock/_lease.py

@@ -5,6 +5,7 @@
 import time
 from contextlib import suppress
 from dataclasses import dataclass
+from math import isfinite
 from threading import Event, Thread, current_thread, local
 from typing import TYPE_CHECKING, Literal
 
@@ -131,8 +132,11 @@ def __init__(
             hide.
 
         """
-        if lease_duration <= 0:
-            msg = f"lease_duration must be positive, got {lease_duration!r}"
+        if isinstance(lease_duration, bool) or not isinstance(lease_duration, (int, float)):
+            msg = f"lease_duration must be a finite positive number, not {type(lease_duration).__name__}"
+            raise TypeError(msg)
+        if not isfinite(lease_duration) or lease_duration <= 0:
+            msg = f"lease_duration must be positive and finite, got {lease_duration!r}"
             raise ValueError(msg)
         if heartbeat_interval is None:
             heartbeat_interval = lease_duration / 3

tests/test_soft_lease.py

@@ -406,19 +406,28 @@ def test_lease_does_not_expire_a_strict_holder(marker: Path) -> None:  # pragma:
 
 
 @pytest.mark.parametrize(
-    ("lease_duration", "heartbeat_interval", "message"),
+    ("lease_duration", "heartbeat_interval", "error", "message"),
     [
-        pytest.param(0, None, "lease_duration must be positive", id="zero-duration"),
-        pytest.param(-1, None, "lease_duration must be positive", id="negative-duration"),
-        pytest.param(_DURATION, 0, "heartbeat_interval must be positive", id="zero-heartbeat"),
-        pytest.param(_DURATION, _DURATION, "below lease_duration", id="heartbeat-equals-duration"),
-        pytest.param(_DURATION, _DURATION * 2, "below lease_duration", id="heartbeat-over-duration"),
+        pytest.param(0, None, ValueError, "lease_duration must be positive", id="zero-duration"),
+        pytest.param(-1, None, ValueError, "lease_duration must be positive", id="negative-duration"),
+        pytest.param(float("nan"), _HEARTBEAT, ValueError, "positive and finite", id="nan-duration"),
+        pytest.param(float("inf"), _HEARTBEAT, ValueError, "positive and finite", id="infinite-duration"),
+        pytest.param(float("-inf"), _HEARTBEAT, ValueError, "positive and finite", id="negative-infinite-duration"),
+        pytest.param(True, None, TypeError, "number, not bool", id="true-duration"),
+        pytest.param(False, None, TypeError, "number, not bool", id="false-duration"),
+        pytest.param(_DURATION, 0, ValueError, "heartbeat_interval must be positive", id="zero-heartbeat"),
+        pytest.param(_DURATION, _DURATION, ValueError, "below lease_duration", id="heartbeat-equals-duration"),
+        pytest.param(_DURATION, _DURATION * 2, ValueError, "below lease_duration", id="heartbeat-over-duration"),
     ],
 )
 def test_lease_rejects_incoherent_settings(
-    marker: Path, lease_duration: float, heartbeat_interval: float | None, message: str
+    marker: Path,
+    lease_duration: float,
+    heartbeat_interval: float | None,
+    error: type[Exception],
+    message: str,
 ) -> None:
-    with pytest.raises(ValueError, match=message):
+    with pytest.raises(error, match=message):
         SoftFileLease(str(marker), lease_duration=lease_duration, heartbeat_interval=heartbeat_interval)