Fix failing staticmethod tests if they are inherited (#8205)

* Fix failing staticmethod tests if they are inherited

* add comments, set default=None

Author: antonblr

AUTHORS

@@ -29,6 +29,7 @@ Andy Freeland
 Anthon van der Neut
 Anthony Shaw
 Anthony Sottile
+Anton Grinevich
 Anton Lodder
 Antony Lee
 Arel Cordero

changelog/8061.bugfix.rst

@@ -0,0 +1 @@
+Fixed failing staticmethod test cases if they are inherited from a parent test class.

src/_pytest/compat.py

@@ -163,7 +163,12 @@ def getfuncargnames(
     # it's passed as an unbound method or function, remove the first
     # parameter name.
     if is_method or (
-        cls and not isinstance(cls.__dict__.get(name, None), staticmethod)
+        # Not using `getattr` because we don't want to resolve the staticmethod.
+        # Not using `cls.__dict__` because we want to check the entire MRO.
+        cls
+        and not isinstance(
+            inspect.getattr_static(cls, name, default=None), staticmethod
+        )
     ):
         arg_names = arg_names[1:]
     # Remove any names that will be replaced with mocks.

testing/python/fixtures.py

@@ -59,6 +59,20 @@ def static(arg1, arg2, x=1):
     assert getfuncargnames(A.static, cls=A) == ("arg1", "arg2")
 
 
+def test_getfuncargnames_staticmethod_inherited() -> None:
+    """Test getfuncargnames for inherited staticmethods (#8061)"""
+
+    class A:
+        @staticmethod
+        def static(arg1, arg2, x=1):
+            raise NotImplementedError()
+
+    class B(A):
+        pass
+
+    assert getfuncargnames(B.static, cls=B) == ("arg1", "arg2")
+
+
 def test_getfuncargnames_partial():
     """Check getfuncargnames for methods defined with functools.partial (#5701)"""
     import functools