Skip symlink sibling test on Windows without symlink support #13771

Author: Mulat Mekonen

AUTHORS

@@ -320,6 +320,7 @@ Mike Hoyle (hoylemd)
 Mike Lundy
 Milan Lesnek
 Miro Hrončok
+Mulat Mekonen
 mrbean-bremen
 Nathan Goldbaum
 Nathan Rousseau

changelog/13771.bugfix.rst

@@ -0,0 +1 @@
+Skip `test_do_not_collect_symlink_siblings` on Windows environments without symlink support to avoid false negatives.

testing/test_collection.py

@@ -1860,6 +1860,27 @@ def test_pyargs_collection_tree(pytester: Pytester, monkeypatch: MonkeyPatch) ->
     )
 
 
+def _can_create_symlink(base: Path) -> bool:
+    """Check if the current environment supports creating symlinks."""
+    target = base / "target"
+    link = base / "link"
+    try:
+        if target.exists():
+            target.rmdir()  # remove old one if exists
+        target.mkdir()
+
+        if link.exists() or link.is_symlink():
+            link.unlink()
+        os.symlink(target, link, target_is_directory=True)
+        return link.is_symlink()
+    except (OSError, NotImplementedError):
+        return False
+
+
+@pytest.mark.skipif(
+    sys.platform.startswith("win"),
+    reason="Symlink behavior on Windows depends on privileges / developer mode",
+)
 def test_do_not_collect_symlink_siblings(
     pytester: Pytester, tmp_path: Path, request: pytest.FixtureRequest
 ) -> None:
@@ -1869,6 +1890,9 @@ def test_do_not_collect_symlink_siblings(
     The check for short paths under Windows via os.path.samefile, introduced in #11936, also finds the symlinked
     directory created by tmp_path/tmpdir.
     """
+    if not _can_create_symlink(tmp_path):
+        pytest.skip("Symlinks not supported in this environment")
+
     # Use tmp_path because it creates a symlink with the name "current" next to the directory it creates.
     symlink_path = tmp_path.parent / (tmp_path.name[:-1] + "current")
     assert symlink_path.is_symlink() is True