From cfc24290a2d0092f5714f1e893f55ac73cf6bc25 Mon Sep 17 00:00:00 2001
From: Fabian Henze <32638720+henzef@users.noreply.github.com>
Date: Sun, 26 Nov 2023 01:12:51 +0100
Subject: [PATCH] B902: Add exceptions for standard library metaclasses (#415)

I faced a false positive when deriving my metaclass from ABCMeta, which should be fixed with this commit. I also added EnumMeta to this list, because it was the only other public metaclass in the standard library.
---
 bugbear.py    | 2 +-
 tests/b024.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/bugbear.py b/bugbear.py
index ee2afd4..88fbd2b 100644
--- a/bugbear.py
+++ b/bugbear.py
@@ -1046,7 +1046,7 @@ def is_classmethod(decorators: Set[str]) -> bool:
             return
 
         bases = {b.id for b in cls.bases if isinstance(b, ast.Name)}
-        if "type" in bases:
+        if any(basetype in bases for basetype in ("type", "ABCMeta", "EnumMeta")):
             if is_classmethod(decorators):
                 expected_first_args = B902.metacls
                 kind = "metaclass class"
diff --git a/tests/b024.py b/tests/b024.py
index 238dcd3..f975887 100644
--- a/tests/b024.py
+++ b/tests/b024.py
@@ -92,7 +92,7 @@ def method(self):
 
 
 class non_keyword_abcmeta_1(ABCMeta):  # safe
-    def method(self):
+    def method(cls):
         foo()