Patch is_reserved for Windows/PosixPurePath

- had been only patched for pathlib.Path

pyfakefs/fake_filesystem.py

@@ -3127,6 +3127,9 @@ def __str__(self) -> str:
             | {f"COM{c}" for c in "123456789\xb9\xb2\xb3"}
             | {f"LPT{c}" for c in "123456789\xb9\xb2\xb3"}
         )
+        _WIN_RESERVED_CHARS = frozenset(
+            {chr(i) for i in range(32)} | {'"', "*", ":", "<", ">", "?", "|", "/", "\\"}
+        )
 
         def isreserved(self, path):
             if not self.is_windows_fs:
@@ -3137,6 +3140,12 @@ def is_reserved_name(name):
                     from os.path import _isreservedname  # type: ignore[import-error]
 
                     return _isreservedname(name)
+
+                if name[-1:] in (".", " "):
+                    return name not in (".", "..")
+                if self._WIN_RESERVED_CHARS.intersection(name):
+                    return True
+                name = name.partition(".")[0].rstrip(" ").upper()
                 return name in self._WIN_RESERVED_NAMES
 
             path = os.fsdecode(self.splitroot(path)[2])

pyfakefs/fake_open.py

@@ -89,6 +89,7 @@ def fake_open(
     if is_called_from_skipped_module(
         skip_names=skip_names,
         case_sensitive=filesystem.is_case_sensitive,
+        check_open_code=sys.version_info >= (3, 12),
     ):
         return io_open(  # pytype: disable=wrong-arg-count
             file,

pyfakefs/fake_pathlib.py

@@ -52,6 +52,13 @@
 from pyfakefs.helpers import IS_PYPY, is_called_from_skipped_module, FSType
 
 
+_WIN_RESERVED_NAMES = (
+    {"CON", "PRN", "AUX", "NUL"}
+    | {"COM%d" % i for i in range(1, 10)}
+    | {"LPT%d" % i for i in range(1, 10)}
+)
+
+
 def init_module(filesystem):
     """Initializes the fake module with the fake file system."""
     # pylint: disable=protected-access
@@ -433,11 +440,6 @@ class _FakeWindowsFlavour(_FakeFlavour):
         implementations independent of FakeFilesystem properties.
         """
 
-        reserved_names = (
-            {"CON", "PRN", "AUX", "NUL"}
-            | {"COM%d" % i for i in range(1, 10)}
-            | {"LPT%d" % i for i in range(1, 10)}
-        )
         sep = "\\"
         altsep = "/"
         has_drv = True
@@ -455,7 +457,7 @@ def is_reserved(self, parts):
             if self.filesystem.is_windows_fs and parts[0].startswith("\\\\"):
                 # UNC paths are never reserved
                 return False
-            return parts[-1].partition(".")[0].upper() in self.reserved_names
+            return parts[-1].partition(".")[0].upper() in _WIN_RESERVED_NAMES
 
         def make_uri(self, path):
             """Return a file URI for the given path"""
@@ -848,33 +850,15 @@ def touch(self, mode=0o666, exist_ok=True):
             fake_file.close()
             self.chmod(mode)
 
-    if sys.version_info >= (3, 12):
-        """These are reimplemented for now because the original implementation
-        checks the flavour against ntpath/posixpath.
-        """
 
-        def is_absolute(self):
-            if self.filesystem.is_windows_fs:
-                return self.drive and self.root
-            return os.path.isabs(self._path())
-
-        def is_reserved(self):
-            if sys.version_info >= (3, 13):
-                warnings.warn(
-                    "pathlib.PurePath.is_reserved() is deprecated and scheduled "
-                    "for removal in Python 3.15. Use os.path.isreserved() to detect "
-                    "reserved paths on Windows.",
-                    DeprecationWarning,
-                )
-            if not self.filesystem.is_windows_fs:
-                return False
-            if sys.version_info < (3, 13):
-                if not self._tail or self._tail[0].startswith("\\\\"):
-                    # UNC paths are never reserved.
-                    return False
-                name = self._tail[-1].partition(".")[0].partition(":")[0].rstrip(" ")
-                return name.upper() in pathlib._WIN_RESERVED_NAMES
-            return self.filesystem.isreserved(self._path())
+def _warn_is_reserved_deprecated():
+    if sys.version_info >= (3, 13):
+        warnings.warn(
+            "pathlib.PurePath.is_reserved() is deprecated and scheduled "
+            "for removal in Python 3.15. Use os.path.isreserved() to detect "
+            "reserved paths on Windows.",
+            DeprecationWarning,
+        )
 
 
 class FakePathlibModule:
@@ -900,12 +884,43 @@ class PurePosixPath(PurePath):
         paths"""
 
         __slots__ = ()
+        if sys.version_info >= (3, 12):
+
+            def is_reserved(self):
+                _warn_is_reserved_deprecated()
+                return False
+
+        def is_absolute(self):
+            with os.path.filesystem.use_fs_type(FSType.POSIX):
+                return os.path.isabs(self)
 
     class PureWindowsPath(PurePath):
         """A subclass of PurePath, that represents Windows filesystem paths"""
 
         __slots__ = ()
 
+        if sys.version_info >= (3, 12):
+            """These are reimplemented because the PurePath implementation
+            checks the flavour against ntpath/posixpath.
+            """
+
+            def is_reserved(self):
+                _warn_is_reserved_deprecated()
+                if sys.version_info < (3, 13):
+                    if not self._tail or self._tail[0].startswith("\\\\"):
+                        # UNC paths are never reserved.
+                        return False
+                    name = (
+                        self._tail[-1].partition(".")[0].partition(":")[0].rstrip(" ")
+                    )
+                    return name.upper() in _WIN_RESERVED_NAMES
+                with os.path.filesystem.use_fs_type(FSType.WINDOWS):
+                    return os.path.isreserved(self)
+
+            def is_absolute(self):
+                with os.path.filesystem.use_fs_type(FSType.WINDOWS):
+                    return bool(self.drive and self.root)
+
     class WindowsPath(FakePath, PureWindowsPath):
         """A subclass of Path and PureWindowsPath that represents
         concrete Windows filesystem paths.

pyfakefs/helpers.py

@@ -478,12 +478,19 @@ def putvalue(self, value: bytes) -> None:
         self._bytestream.write(value)
 
 
-def is_called_from_skipped_module(skip_names: list, case_sensitive: bool) -> bool:
+def is_called_from_skipped_module(
+    skip_names: list, case_sensitive: bool, check_open_code: bool = False
+) -> bool:
     def starts_with(path, string):
         if case_sensitive:
             return path.startswith(string)
         return path.lower().startswith(string.lower())
 
+    # in most cases we don't have skip names and won't need the overhead
+    # of analyzing the traceback, except when checking for open_code
+    if not skip_names and not check_open_code:
+        return False
+
     stack = traceback.extract_stack()
 
     # handle the case that we try to call the original `open_code`
@@ -494,12 +501,15 @@ def starts_with(path, string):
     # -3: fake_io.open: 'return fake_open('
     # -4: fake_io.open_code : 'return self._io_module.open_code(path)'
     if (
-        sys.version_info >= (3, 12)
+        check_open_code
         and stack[-4].name == "open_code"
         and stack[-4].line == "return self._io_module.open_code(path)"
     ):
         return True
 
+    if not skip_names:
+        return False
+
     caller_filename = next(
         (
             frame.filename