Switch to typing_extensions.Self for __new__ implementations

src/graphql/pyutils/undefined.py

@@ -1,6 +1,7 @@
 """The Undefined value"""
 
 from __future__ import annotations
+from typing_extensions import Self
 
 import warnings
 
@@ -12,7 +13,7 @@ class UndefinedType:
 
     _instance: UndefinedType | None = None
 
-    def __new__(cls) -> UndefinedType:
+    def __new__(cls) -> Self:
         """Create the Undefined singleton."""
         if cls._instance is None:
             cls._instance = super().__new__(cls)

src/graphql/type/definition.py

@@ -14,6 +14,7 @@
     cast,
     overload,
 )
+from typing_extensions import Self
 
 if TYPE_CHECKING:
     from typing import TypeAlias, TypeGuard
@@ -232,7 +233,7 @@ class GraphQLNamedType(GraphQLType):
 
     reserved_types: Mapping[str, GraphQLNamedType] = {}
 
-    def __new__(cls, name: str, *_args: Any, **_kwargs: Any) -> GraphQLNamedType:
+    def __new__(cls, name: str, *_args: Any, **_kwargs: Any) -> Self:
         """Create a GraphQL named type."""
         if name in cls.reserved_types:
             msg = f"Redefinition of reserved type {name!r}"