Fix mock.patch compatibility with Python 3.11+

- Use mock.patch.object() instead of string-based mock.patch()
- Add cache_clear() call before mocking load_library
- Fixes AttributeError in TestLibraryIntegration tests

The string-based mock.patch() path resolution changed in Python 3.11+
(using pkgutil.resolve_name()), which can fail to find attributes that
were imported into a module from elsewhere.

See: python/cpython#117860

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gijzelaerr

tests/test_client.py

@@ -947,18 +947,25 @@ def test_set_param(self) -> None:
 @pytest.mark.client
 class TestLibraryIntegration(unittest.TestCase):
     def setUp(self) -> None:
-        # replace the function load_library with a mock
-        self.loadlib_patch = mock.patch("snap7.client.load_library")
-        self.loadlib_func = self.loadlib_patch.start()
+        # Clear the cache on load_library to ensure mock is used
+        from snap7.common import load_library
+
+        load_library.cache_clear()
 
         # have load_library return another mock
         self.mocklib = mock.MagicMock()
-        self.loadlib_func.return_value = self.mocklib
 
         # have the Cli_Create of the mock return None
         self.mocklib.Cli_Create.return_value = None
         self.mocklib.Cli_Destroy.return_value = None
 
+        # replace the function load_library with a mock
+        # Use patch.object for Python 3.11+ compatibility (avoids path resolution issues)
+        import snap7.client
+
+        self.loadlib_patch = mock.patch.object(snap7.client, "load_library", return_value=self.mocklib)
+        self.loadlib_func = self.loadlib_patch.start()
+
     def tearDown(self) -> None:
         # restore load_library
         self.loadlib_patch.stop()

tests/test_server.py

@@ -146,18 +146,25 @@ def test_set_param(self) -> None:
 @pytest.mark.server
 class TestLibraryIntegration(unittest.TestCase):
     def setUp(self) -> None:
-        # replace the function load_library with a mock
-        self.loadlib_patch = mock.patch("snap7.server.load_library")
-        self.loadlib_func = self.loadlib_patch.start()
+        # Clear the cache on load_library to ensure mock is used
+        from snap7.common import load_library
+
+        load_library.cache_clear()
 
         # have load_library return another mock
         self.mocklib = mock.MagicMock()
-        self.loadlib_func.return_value = self.mocklib
 
         # have the Srv_Create of the mock return None
         self.mocklib.Srv_Create.return_value = None
         self.mocklib.Srv_Destroy.return_value = None
 
+        # replace the function load_library with a mock
+        # Use patch.object for Python 3.11+ compatibility (avoids path resolution issues)
+        import snap7.server
+
+        self.loadlib_patch = mock.patch.object(snap7.server, "load_library", return_value=self.mocklib)
+        self.loadlib_func = self.loadlib_patch.start()
+
     def tearDown(self) -> None:
         # restore load_library
         self.loadlib_patch.stop()