Add support for current Python 3.12

- adapt for changed pathlib implementation (removed flavour implementation)
- Windows: add patching for some os.path functions now implemented in nt instead of ntpath
- fix handling of devnull for changed OS
- add fake implementation for os.path.splitroot
- fixes #770

Author: mrbean-bremen

.github/workflows/testsuite.yml

@@ -10,8 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
-        python-version: [3.7, 3.8, 3.9, "3.10", "3.11"]
-#        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12-dev"]
+        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12-dev"]
         include:
           - python-version: "pypy-3.7"
             os: ubuntu-latest

CHANGES.md

@@ -17,6 +17,8 @@ The released versions correspond to PyPI releases.
 ### Features
 * added possibility to set a path inaccessible under Windows by using `chown()` with
   the `force_unix_mode` flag (see [#720](../../issues/720))
+* added support for changes in Python 3.12 (currently in last beta version)
+* added support for `os.path.splitroot` (new in Python 3.12)
 
 ## [Version 5.1.0](https://pypi.python.org/pypi/pyfakefs/5.1.0) (2023-01-12)
 New version before Debian freeze

pyfakefs/fake_filesystem.py

@@ -325,6 +325,7 @@ def reset(self, total_size: Optional[int] = None):
         """Remove all file system contents and reset the root."""
         self.root = FakeDirectory(self.path_separator, filesystem=self)
 
+        self.dev_null = FakeNullFile(self)
         self.open_files = []
         self._free_fd_heap = []
         self.last_ino = 0
@@ -1071,6 +1072,62 @@ def splitdrive(self, path: AnyStr) -> Tuple[AnyStr, AnyStr]:
                     return path_str[:2], path_str[2:]
         return path_str[:0], path_str
 
+    def splitroot(self, path: AnyStr):
+        """Split a pathname into drive, root and tail.
+        Implementation taken from ntpath and posixpath.
+        """
+        p = os.fspath(path)
+        if isinstance(p, bytes):
+            sep = self.path_separator.encode()
+            altsep = None
+            if self.alternative_path_separator:
+                altsep = self.alternative_path_separator.encode()
+            colon = b":"
+            unc_prefix = b"\\\\?\\UNC\\"
+            empty = b""
+        else:
+            sep = self.path_separator
+            altsep = self.alternative_path_separator
+            colon = ":"
+            unc_prefix = "\\\\?\\UNC\\"
+            empty = ""
+        if self.is_windows_fs:
+            normp = p.replace(altsep, sep) if altsep else p
+            if normp[:1] == sep:
+                if normp[1:2] == sep:
+                    # UNC drives, e.g. \\server\share or \\?\UNC\server\share
+                    # Device drives, e.g. \\.\device or \\?\device
+                    start = 8 if normp[:8].upper() == unc_prefix else 2
+                    index = normp.find(sep, start)
+                    if index == -1:
+                        return p, empty, empty
+                    index2 = normp.find(sep, index + 1)
+                    if index2 == -1:
+                        return p, empty, empty
+                    return p[:index2], p[index2 : index2 + 1], p[index2 + 1 :]
+                else:
+                    # Relative path with root, e.g. \Windows
+                    return empty, p[:1], p[1:]
+            elif normp[1:2] == colon:
+                if normp[2:3] == sep:
+                    # Absolute drive-letter path, e.g. X:\Windows
+                    return p[:2], p[2:3], p[3:]
+                else:
+                    # Relative path with drive, e.g. X:Windows
+                    return p[:2], empty, p[2:]
+            else:
+                # Relative path, e.g. Windows
+                return empty, empty, p
+        else:
+            if p[:1] != sep:
+                # Relative path, e.g.: 'foo'
+                return empty, empty, p
+            elif p[1:2] != sep or p[2:3] == sep:
+                # Absolute path, e.g.: '/foo', '///foo', '////foo', etc.
+                return empty, sep, p[1:]
+            else:
+                return empty, p[:2], p[2:]
+
     def _join_paths_with_drive_support(self, *all_paths: AnyStr) -> AnyStr:
         """Taken from Python 3.5 os.path.join() code in ntpath.py
         and slightly adapted"""

pyfakefs/fake_filesystem_unittest.py

@@ -653,7 +653,9 @@ def _init_fake_module_classes(self) -> None:
         if IS_PYPY:
             # in PyPy io.open, the module is referenced as _io
             self._fake_module_classes["_io"] = fake_io.FakeIoModule
-        if sys.platform != "win32":
+        if sys.platform == "win32":
+            self._fake_module_classes["nt"] = fake_path.FakeNtModule
+        else:
             self._fake_module_classes["fcntl"] = fake_filesystem.FakeFcntlModule
 
         # class modules maps class names against a list of modules they can

pyfakefs/fake_path.py

@@ -101,7 +101,7 @@ def dir() -> List[str]:
             "samefile",
         ]
         if sys.version_info >= (3, 12):
-            dir_list.append("isjunction")
+            dir_list += ["isjunction", "splitroot"]
         return dir_list
 
     def __init__(self, filesystem: "FakeFilesystem", os_module: "FakeOsModule"):
@@ -198,6 +198,12 @@ def isjunction(self, path: AnyStr) -> bool:
             """Returns False. Junctions are never faked."""
             return self.filesystem.isjunction(path)
 
+        def splitroot(self, path: AnyStr):
+            """Split a pathname into drive, root and tail.
+            Implementation taken from ntpath and posixpath.
+            """
+            return self.filesystem.splitroot(path)
+
     def getmtime(self, path: AnyStr) -> float:
         """Returns the modification time of the fake file.
 
@@ -473,3 +479,52 @@ def ismount(self, path: AnyStr) -> bool:
     def __getattr__(self, name: str) -> Any:
         """Forwards any non-faked calls to the real os.path."""
         return getattr(self._os_path, name)
+
+
+if sys.platform == "win32":
+
+    class FakeNtModule:
+        """Under windows, a few function of `os.path` are taken from the `nt` module
+        for performance reasons. These are patched here.
+        """
+
+        @staticmethod
+        def dir():
+            if sys.version_info >= (3, 12):
+                return ["_path_exists", "_path_isfile", "_path_isdir", "_path_islink"]
+            else:
+                return ["_isdir"]
+
+        def __init__(self, filesystem: "FakeFilesystem"):
+            """Init.
+
+            Args:
+                filesystem: FakeFilesystem used to provide file system information
+            """
+            import nt
+
+            self.filesystem = filesystem
+            self.nt_module: Any = nt
+
+        if sys.version_info >= (3, 12):
+
+            def _path_isdir(self, path: AnyStr) -> bool:
+                return self.filesystem.isdir(path)
+
+            def _path_isfile(self, path: AnyStr) -> bool:
+                return self.filesystem.isfile(path)
+
+            def _path_islink(self, path: AnyStr) -> bool:
+                return self.filesystem.islink(path)
+
+            def _path_exists(self, path: AnyStr) -> bool:
+                return self.filesystem.exists(path)
+
+        else:
+
+            def _isdir(self, path: AnyStr) -> bool:
+                return self.filesystem.isdir(path)
+
+        def __getattr__(self, name: str) -> Any:
+            """Forwards any non-faked calls to the real nt module."""
+            return getattr(self.nt_module, name)