Initial commit

tests/test_engine_pid.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+
+import os
+import unittest
+from unittest.mock import patch
+
+from opc import engine as engine_module
+from opc.engine import OPCEngine
+
+
+class EnginePidProbeTests(unittest.TestCase):
+    def test_current_process_is_running(self) -> None:
+        self.assertTrue(OPCEngine._pid_is_running(os.getpid()))
+
+    def test_posix_probe_treats_unexpected_oserror_as_not_running(self) -> None:
+        with patch.object(engine_module.os, "name", "posix"), patch.object(
+            engine_module.os,
+            "kill",
+            side_effect=OSError("platform probe failed"),
+        ):
+            self.assertFalse(OPCEngine._pid_is_running(12345))
+