Add support for Python 3.14 pathlib copy methods

- support pathlib.copy and pathlib.copy_into
- add tests for pathlib.move and pathlib move_into

Author: mrbean-bremen

CHANGES.md

@@ -22,6 +22,7 @@ The released versions correspond to PyPI releases.
 
 ### Enhancements
 * added support for `os.readinto` in Python 3.14
+* added support for `pathlib.copy` and `pathlib.copy_into` in Python 3.14
 
 ### Fixes
 * fixes patching of Debian-specific `tempfile` in Python 3.13 (see [#1214](../../issues/1214))

pyfakefs/fake_pathlib.py

@@ -845,6 +845,35 @@ def touch(self, mode=0o666, exist_ok=True):
             fake_file.close()
             self.chmod(mode)
 
+    if sys.version_info >= (3, 14):
+
+        def _copy_from_file(self, source, preserve_metadata=False):
+            if sys.platform == "win32":
+                # do not use the optimized version that uses OS functions in Windows
+                if hasattr(self, "_copy_from_file_fallback"):
+                    return self._copy_from_file_fallback(source, preserve_metadata)
+                else:
+                    return super()._copy_from_file(source, preserve_metadata)  # type: ignore[attr-defined]
+            else:
+                # make pathlib think that no system calls are available so that it
+                # will fall back to pure Python calls
+                pathlib_os = pathlib.pathlib_module._os  # type: ignore[attr-defined]
+                old_fcopyfile = pathlib_os._fcopyfile
+                pathlib_os._fcopyfile = None
+                old_copy_file_range = pathlib_os._copy_file_range  # type: ignore[attr-defined]
+                pathlib_os._copy_file_range = None
+                old_ficlone = pathlib_os._ficlone  # type: ignore[attr-defined]
+                pathlib_os._ficlone = None
+                old_sendfile = pathlib_os._sendfile  # type: ignore[attr-defined]
+                pathlib_os._sendfile = None
+                try:
+                    return super()._copy_from_file(source, preserve_metadata)  # type: ignore[attr-defined]
+                finally:
+                    pathlib_os._fcopyfile = old_fcopyfile
+                    pathlib_os._copy_file_range = old_copy_file_range
+                    pathlib_os._ficlone = old_ficlone
+                    pathlib_os._sendfile = old_sendfile
+
 
 def _warn_is_reserved_deprecated():
     if sys.version_info >= (3, 13):
@@ -875,7 +904,7 @@ def __init__(self, filesystem, from_patcher=False):
                 Will be set to `True` if instantiated from `Patcher`.
         """
         init_module(filesystem)
-        self._pathlib_module = pathlib
+        self.pathlib_module = pathlib
         self._os = None
         self._os_patcher = None
         if not from_patcher:
@@ -998,7 +1027,7 @@ def glob(self, pattern, *, case_sensitive=None, recurse_symlinks=False):
 
     def __getattr__(self, name):
         """Forwards any unfaked calls to the standard pathlib module."""
-        return getattr(self._pathlib_module, name)
+        return getattr(self.pathlib_module, name)
 
 
 class FakePathlibPathModule:

pyfakefs/tests/fake_pathlib_test.py

@@ -1376,6 +1376,107 @@ def test_owner_and_group_windows(self):
         with self.assertRaises(NotImplementedError):
             self.path(path).group()
 
+    @unittest.skipIf(sys.version_info < (3, 14), "copy() is new in Python 3.14")
+    def test_copy_new_file(self):
+        source_path = self.path(self.make_path("some_file"))
+        target_path = self.make_path("some_other_file")
+        self.create_file(source_path, contents="test")
+        target = source_path.copy(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertTrue(target.exists())
+        self.assertEqual("test", target.read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "copy() is new in Python 3.14")
+    def test_copy_to_existing_file(self):
+        source_path = self.path(self.make_path("some_file"))
+        target_path = self.make_path("some_other_file")
+        self.create_file(source_path, contents="foo")
+        self.create_file(target_path, contents="bar")
+        target = source_path.copy(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertTrue(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertEqual("foo", target.read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "copy() is new in Python 3.14")
+    def test_copy_directory(self):
+        source_path = self.path(self.make_path("some_dir"))
+        self.create_file(source_path / "foo", contents="foo")
+        self.create_file(source_path / "bar", contents="bar")
+        self.create_dir(source_path / "dir")
+        target_path = self.make_path("new_dir")
+        target = source_path.copy(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertTrue(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertTrue((target / "foo").exists())
+        self.assertEqual("foo", (target / "foo").read_text())
+        self.assertEqual("bar", (target / "bar").read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "copy_into() is new in Python 3.14")
+    def test_copy_into(self):
+        source_dir = self.path(self.make_path("some_dir"))
+        source_path = source_dir / "foo"
+        self.create_file(source_path, contents="foo")
+        target_path = self.path(self.make_path("new_dir"))
+        self.create_dir(target_path)
+        target = source_path.copy_into(target_path)
+        self.assertTrue(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertEqual(str(target_path / "foo"), str(target))
+        self.assertEqual("foo", target.read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "move() is new in Python 3.14")
+    def test_move_file(self):
+        source_path = self.path(self.make_path("some_file"))
+        target_path = self.make_path("some_other_file")
+        self.create_file(source_path, contents="test")
+        target = source_path.move(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertFalse(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertEqual("test", target.read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "move() is new in Python 3.14")
+    def test_move_to_existing_file(self):
+        source_path = self.path(self.make_path("some_file"))
+        target_path = self.make_path("some_other_file")
+        self.create_file(source_path, contents="foo")
+        self.create_file(target_path, contents="bar")
+        target = source_path.move(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertFalse(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertEqual("foo", target.read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "move() is new in Python 3.14")
+    def test_move_directory(self):
+        source_path = self.path(self.make_path("some_dir"))
+        self.create_file(source_path / "foo", contents="foo")
+        self.create_file(source_path / "bar", contents="bar")
+        self.create_dir(source_path / "dir")
+        target_path = self.make_path("new_dir")
+        target = source_path.move(target_path)
+        self.assertEqual(target_path, str(target))
+        self.assertFalse(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertTrue((target / "foo").exists())
+        self.assertEqual("foo", (target / "foo").read_text())
+        self.assertEqual("bar", (target / "bar").read_text())
+
+    @unittest.skipIf(sys.version_info < (3, 14), "move_into() is new in Python 3.14")
+    def test_move_into(self):
+        source_dir = self.path(self.make_path("some_dir"))
+        source_path = source_dir / "foo"
+        self.create_file(source_path, contents="foo")
+        target_path = self.path(self.make_path("new_dir"))
+        self.create_dir(target_path)
+        target = source_path.move_into(target_path)
+        self.assertFalse(source_path.exists())
+        self.assertTrue(target.exists())
+        self.assertEqual(str(target_path / "foo"), str(target))
+        self.assertEqual("foo", target.read_text())
+
     def test_walk(self):
         """Regression test for #915 - walk results shall be strings."""
         base_dir = self.make_path("foo")