From c0f3789460540aec76a54bea30f2bbcb0028dd00 Mon Sep 17 00:00:00 2001
From: Bernat Gabor <gaborjbernat@gmail.com>
Date: Thu, 16 Jul 2026 09:29:36 -0700
Subject: [PATCH] Make SimplePath path parameters positional-only

pathlib.Path does not satisfy SimplePath under ty or pyrefly. The protocol
names the joinpath and __truediv__ parameter `other`, while typeshed names
Path's `key` and `*other`. Neither side is positional-only, so the typing
spec requires the names to match, and they do not.

Marking the parameters positional-only reflects how both members are called
and lets Path satisfy the protocol. mypy passes before and after.

Closes #542
---
 importlib_metadata/_meta.py  | 4 ++--
 newsfragments/542.bugfix.rst | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)
 create mode 100644 newsfragments/542.bugfix.rst

diff --git a/importlib_metadata/_meta.py b/importlib_metadata/_meta.py
index 0c20eff3..219b2a86 100644
--- a/importlib_metadata/_meta.py
+++ b/importlib_metadata/_meta.py
@@ -54,11 +54,11 @@ class SimplePath(Protocol):
     """
 
     def joinpath(
-        self, other: str | os.PathLike[str]
+        self, other: str | os.PathLike[str], /
     ) -> SimplePath: ...  # pragma: no cover
 
     def __truediv__(
-        self, other: str | os.PathLike[str]
+        self, other: str | os.PathLike[str], /
     ) -> SimplePath: ...  # pragma: no cover
 
     @property
diff --git a/newsfragments/542.bugfix.rst b/newsfragments/542.bugfix.rst
new file mode 100644
index 00000000..316e28ba
--- /dev/null
+++ b/newsfragments/542.bugfix.rst
@@ -0,0 +1 @@
+Marked the ``other`` parameter of ``SimplePath.joinpath`` and ``SimplePath.__truediv__`` positional-only, so ``pathlib.Path`` satisfies the protocol under type checkers that compare parameter names.