Show warning when trying to deep copy a schema (#100)

src/graphql/pyutils/frozen_dict.py

@@ -24,12 +24,12 @@ def __iadd__(self, value):
     def __hash__(self):
         return hash(tuple(self.items()))
 
-    def __copy__(self):
+    def __copy__(self) -> "FrozenDict":
         return FrozenDict(self)
 
     copy = __copy__
 
-    def __deepcopy__(self, memo):
+    def __deepcopy__(self, memo: Dict) -> "FrozenDict":
         return FrozenDict({k: deepcopy(v, memo) for k, v in self.items()})
 
     def clear(self):

src/graphql/pyutils/frozen_list.py

@@ -1,5 +1,5 @@
 from copy import deepcopy
-from typing import List, TypeVar
+from typing import Dict, List, TypeVar
 
 from .frozen_error import FrozenError
 
@@ -35,10 +35,10 @@ def __imul__(self, value):
     def __hash__(self):
         return hash(tuple(self))
 
-    def __copy__(self):
+    def __copy__(self) -> "FrozenList":
         return FrozenList(self)
 
-    def __deepcopy__(self, memo):
+    def __deepcopy__(self, memo: Dict) -> "FrozenList":
         return FrozenList(deepcopy(value, memo) for value in self)
 
     def append(self, x):

src/graphql/type/definition.py

@@ -252,6 +252,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             extension_ast_nodes=self.extension_ast_nodes or FrozenList(),
         )
 
+    def __copy__(self) -> "GraphQLNamedType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
 
 def is_named_type(type_: Any) -> bool:
     return isinstance(type_, GraphQLNamedType)
@@ -428,6 +431,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             specified_by_url=self.specified_by_url,
         )
 
+    def __copy__(self) -> "GraphQLScalarType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
 
 def is_scalar_type(type_: Any) -> bool:
     return isinstance(type_, GraphQLScalarType)
@@ -539,6 +545,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             ast_node=self.ast_node,
         )
 
+    def __copy__(self) -> "GraphQLField":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @property
     def is_deprecated(self) -> bool:
         return self.deprecation_reason is not None
@@ -649,6 +658,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             ast_node=self.ast_node,
         )
 
+    def __copy__(self) -> "GraphQLArgument":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
 
 def is_required_argument(arg: GraphQLArgument) -> bool:
     return is_non_null_type(arg.type) and arg.default_value is Undefined
@@ -736,6 +748,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             is_type_of=self.is_type_of,
         )
 
+    def __copy__(self) -> "GraphQLObjectType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @cached_property
     def fields(self) -> GraphQLFieldMap:
         """Get provided fields, wrapping them as GraphQLFields if needed."""
@@ -856,6 +871,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             resolve_type=self.resolve_type,
         )
 
+    def __copy__(self) -> "GraphQLInterfaceType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @cached_property
     def fields(self) -> GraphQLFieldMap:
         """Get provided fields, wrapping them as GraphQLFields if needed."""
@@ -974,6 +992,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             **super().to_kwargs(), types=self.types, resolve_type=self.resolve_type
         )
 
+    def __copy__(self) -> "GraphQLUnionType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @cached_property
     def types(self) -> List[GraphQLObjectType]:
         """Get provided types."""
@@ -1095,6 +1116,9 @@ def __init__(
     def to_kwargs(self) -> Dict[str, Any]:
         return dict(**super().to_kwargs(), values=self.values.copy())
 
+    def __copy__(self) -> "GraphQLEnumType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @cached_property
     def _value_lookup(self) -> Dict[Any, str]:
         # use first value or name as lookup
@@ -1232,6 +1256,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             ast_node=self.ast_node,
         )
 
+    def __copy__(self) -> "GraphQLEnumValue":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @property
     def is_deprecated(self) -> bool:
         return self.deprecation_reason is not None
@@ -1321,6 +1348,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             else self.out_type,
         )
 
+    def __copy__(self) -> "GraphQLInputObjectType":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
     @cached_property
     def fields(self) -> GraphQLInputFieldMap:
         """Get provided fields, wrap them as GraphQLInputField if needed."""
@@ -1422,6 +1452,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             ast_node=self.ast_node,
         )
 
+    def __copy__(self) -> "GraphQLInputField":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
 
 def is_required_input_field(field: GraphQLInputField) -> bool:
     return is_non_null_type(field.type) and field.default_value is Undefined

src/graphql/type/directives.py

@@ -128,6 +128,9 @@ def to_kwargs(self) -> Dict[str, Any]:
             ast_node=self.ast_node,
         )
 
+    def __copy__(self) -> "GraphQLDirective":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
 
 def is_directive(directive: Any) -> bool:
     """Test if the given value is a GraphQL directive."""

src/graphql/type/schema.py

@@ -9,6 +9,7 @@
     Union,
     cast,
 )
+from warnings import warn
 
 from ..error import GraphQLError
 from ..language import ast
@@ -285,6 +286,13 @@ def to_kwargs(self) -> Dict[str, Any]:
             assume_valid=self._validation_errors is not None,
         )
 
+    def __copy__(self) -> "GraphQLSchema":  # pragma: no cover
+        return self.__class__(**self.to_kwargs())
+
+    def __deepcopy__(self, memo_: Dict) -> "GraphQLSchema":  # pragma: no cover
+        warn("Cannot deep copy a schema. Creating a flat copy instead.")
+        return self.__copy__()
+
     def get_type(self, name: str) -> Optional[GraphQLNamedType]:
         return self.type_map.get(name)