Make nodes extensible and weak-referencable

src/graphql/execution/middleware.py

@@ -20,7 +20,7 @@ class MiddlewareManager:
     must be aware of this and check whether values are awaitable before awaiting them.
     """
 
-    __slots__ = "middlewares", "_middleware_resolvers", "_cached_resolvers"
+    __slots__ = "__weakref__", "__dict__", "middlewares", "_middleware_resolvers", "_cached_resolvers"
 
     _cached_resolvers: Dict[GraphQLFieldResolver, GraphQLFieldResolver]
     _middleware_resolvers: Optional[List[Callable]]

src/graphql/language/ast.py

@@ -214,7 +214,7 @@ class OperationType(Enum):
 class Node:
     """AST nodes"""
 
-    __slots__ = ("loc",)
+    __slots__ = ("__dict__", "__weakref__", "loc",)
 
     loc: Optional[Location]
 

src/graphql/language/source.py

@@ -6,7 +6,7 @@
 class Source:
     """A representation of source input to GraphQL."""
 
-    __slots__ = "body", "name", "location_offset"
+    __slots__ = "__weakref__", "__dict__", "body", "name", "location_offset"
 
     def __init__(
         self,

tests/language/test_ast.py

@@ -1,4 +1,5 @@
 from copy import copy, deepcopy
+import weakref
 
 from graphql.language import Location, Node, Source, Token, TokenKind
 from graphql.pyutils import inspect
@@ -224,3 +225,13 @@ class Foo(Node):
 
     def provides_keys_as_class_attribute():
         assert SampleTestNode.keys == ["loc", "alpha", "beta"]
+
+    def can_weakref():
+        node = SampleTestNode(alpha=1, beta=2)
+        wr = weakref.ref(node)  # That this works is 90% of the test
+        assert wr() is node
+
+    def can_make_attrs():
+        node = SampleTestNode(alpha=1, beta=2)
+        node.__new_random_attr = "Hello!"  # That this works is 90% of the test
+        assert node.__new_random_attr == "Hello!"