Fix error behavior for the hardlink_to backport and symlink_to for upath.extensions (#508)

* upath: small fixes for hardlink_to backports

* tests: update symlink and hardlink tests

* tests: lchmod might not be available

* tests: better check for lchmod test

* tests: adjust lchmod

* tests: lchmod raises notimplemented on linux

Author: ap--

upath/extensions.py

@@ -16,6 +16,7 @@
 from urllib.parse import SplitResult
 
 from fsspec import AbstractFileSystem
+from pathlib_abc import vfspath
 
 from upath._chain import Chain
 from upath._chain import ChainSegment
@@ -160,6 +161,8 @@ def symlink_to(
         target: ReadablePathLike,
         target_is_directory: bool = False,
     ) -> None:
+        if not isinstance(target, str):
+            target = vfspath(target)
         self.__wrapped__.symlink_to(target, target_is_directory=target_is_directory)
 
     def mkdir(
@@ -431,6 +434,8 @@ def is_relative_to(self, other, /, *_deprecated) -> bool:  # type: ignore[overri
         return self.__wrapped__.is_relative_to(other, *_deprecated)
 
     def hardlink_to(self, target: ReadablePathLike) -> None:
+        if not isinstance(target, str):
+            target = vfspath(target)
         return self.__wrapped__.hardlink_to(target)
 
     def match(self, pattern: str, *, case_sensitive: bool | None = None) -> bool:

upath/implementations/local.py

@@ -642,7 +642,7 @@ def relative_to(  # type: ignore[override]
 
         def hardlink_to(self, target: ReadablePathLike) -> None:
             try:
-                os.link(target, self)  # type: ignore[arg-type]
+                os.link(os.fspath(target), os.fspath(self))  # type: ignore[arg-type]
             except AttributeError:
                 raise UnsupportedOperation("hardlink operation not supported")
 

upath/tests/test_extensions.py

@@ -1,5 +1,6 @@
 import os
 import sys
+from contextlib import nullcontext
 
 import pytest
 
@@ -130,6 +131,30 @@ def test_cwd(self):
         with pytest.raises(UnsupportedOperation):
             type(self.path).cwd()
 
+    def test_lchmod(self):
+        # setup
+        a = self.path.joinpath("a")
+        b = self.path.joinpath("b")
+        a.touch()
+        b.symlink_to(a)
+
+        # see: https://github.com/python/cpython/issues/108660#issuecomment-1854645898
+        if hasattr(os, "lchmod") or os.chmod in os.supports_follow_symlinks:
+            cm = nullcontext()
+        else:
+            cm = pytest.raises((UnsupportedOperation, NotImplementedError))
+        with cm:
+            b.lchmod(mode=0o777)
+
+    def test_symlink_to(self):
+        self.path.joinpath("link").symlink_to(self.path)
+
+    def test_hardlink_to(self):
+        try:
+            self.path.joinpath("link").hardlink_to(self.path)
+        except PermissionError:
+            pass  # hardlink may require elevated permissions
+
 
 def test_custom_subclass():