Remove pathlib.PurePath.__eq__ (#10662)

Fixes #10661

Co-authored-by: Alex Waygood <[email protected]>

Author: hauntsaninja

stdlib/pathlib.pyi

@@ -46,7 +46,6 @@ class PurePath(PathLike[str]):
         def __new__(cls, *args: StrPath) -> Self: ...
 
     def __hash__(self) -> int: ...
-    def __eq__(self, other: object) -> bool: ...
     def __fspath__(self) -> str: ...
     def __lt__(self, other: PurePath) -> bool: ...
     def __le__(self, other: PurePath) -> bool: ...

test_cases/stdlib/check_pathlib.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+from pathlib import Path, PureWindowsPath
+
+if Path("asdf") == Path("asdf"):
+    ...
+
+# https://github.com/python/typeshed/issues/10661
+# Provide a true positive error when comparing Path to str
+# mypy should report a comparison-overlap error with --strict-equality,
+# and pyright should report a reportUnnecessaryComparison error
+if Path("asdf") == "asdf":  # type: ignore
+    ...
+
+# Errors on comparison here are technically false positives. However, this comparison is a little
+# interesting: it can never hold true on Posix, but could hold true on Windows. We should experiment
+# with more accurate __new__, such that we only get an error for such comparisons on platforms
+# where they can never hold true.
+if PureWindowsPath("asdf") == Path("asdf"):  # type: ignore
+    ...