Correctly handle setting cwd to a pathlib.Path

- fixes #1108

CHANGES.md

@@ -17,6 +17,7 @@ The released versions correspond to PyPI releases.
 ### Fixes
 * fixed a problem with module and session scoped fixtures in Python 3.13
   (see [#1101](../../issues/1101))
+* fixed handling of `cwd` if set to a `pathlib.Path` (see [#1108](../../issues/1108))
 
 ## [Version 5.7.3](https://pypi.python.org/pypi/pyfakefs/5.7.3) (2024-12-15)
 Fixes a regression in version 5.7.3.

pyfakefs/fake_filesystem.py

@@ -346,7 +346,10 @@ def cwd(self, value: str) -> None:
         """Set the current working directory of the fake filesystem.
         Make sure a new drive or share is auto-mounted under Windows.
         """
-        self._cwd = value
+        _cwd = make_string_path(value)
+        self._cwd = _cwd.replace(
+            matching_string(_cwd, os.sep), matching_string(_cwd, self.path_separator)
+        )
         self._auto_mount_drive_if_needed(value)
 
     @property

pyfakefs/tests/fake_filesystem_test.py

@@ -17,6 +17,7 @@
 import contextlib
 import errno
 import os
+import pathlib
 import shutil
 import stat
 import sys
@@ -231,6 +232,10 @@ def test_relative_path_forced_to_cwd(self):
         self.filesystem.cwd = "/foo"
         self.assertEqual("/foo/bar", self.filesystem.absnormpath(path))
 
+    def test_cwd_from_pathlib_path(self):
+        self.filesystem.cwd = pathlib.Path("/foo/bar")
+        self.assertEqual("/foo/bar", self.filesystem.cwd)
+
     def test_absolute_path_remains_unchanged(self):
         path = "foo/bar"
         self.assertEqual(self.root_name + path, self.filesystem.absnormpath(path))