add a check for classmethods

Author: EmmanuelNiyonshuti

mypy/semanal.py

@@ -1191,6 +1191,8 @@ def is_expected_self_type(self, typ: Type, is_classmethod: bool) -> bool:
                 sym = self.lookup_qualified(typ.name, typ, suppress_errors=True)
                 if sym is not None and sym.fullname in TYPE_NAMES and typ.args:
                     return self.is_expected_self_type(typ.args[0], is_classmethod=False)
+                if sym is not None and sym.fullname in ANNOTATED_TYPE_NAMES and typ.args:
+                    return self.is_expected_self_type(typ.args[0], is_classmethod=True)
             return False
         if isinstance(typ, TypeVarType):
             return typ == self.type.self_type

test-data/unit/check-selftype.test

@@ -1559,7 +1559,12 @@ class C:
     def foo(self: Annotated[Self, "some_metadata"], x: int) -> None:
         ...
 
+    @classmethod
+    def bar(self: Annotated[type[Self], "some_metadata"], x: int) -> None:
+        ...
+
 reveal_type(C.foo) # N: Revealed type is "def [Self <: __main__.C] (self: Self`2, x: builtins.int)"
+reveal_type(C.bar) # N: Revealed type is "def (x: builtins.int)"
 [builtins fixtures/tuple.pyi]
 
 [case testTypingSelfOverload]