Keep Federation support types out of SDL

Amp-Thread-ID: https://ampcode.com/threads/T-01a04d3e-60f6-7768-ba15-4f10d54eea17

Author: patrick91

strawberry/federation/schema.py

@@ -32,6 +32,7 @@
 
 if TYPE_CHECKING:
     from graphql import ExecutionContext as GraphQLExecutionContext
+    from graphql import GraphQLNamedType
 
     from strawberry.extensions import SchemaExtension
     from strawberry.federation.schema_directives import ComposeDirective
@@ -44,6 +45,14 @@
 FederationAny = NewType("FederationAny", object)
 """Represents the _Any scalar type used in federation entity resolution."""
 
+_PRIVATE_FEDERATION_TYPES = frozenset(
+    {
+        "_FieldSet",
+        "link__Import",
+        "link__Purpose",
+    }
+)
+
 
 class Schema(BaseSchema):
     def __init__(  # noqa: PLR0917
@@ -370,6 +379,9 @@ def _warn_for_federation_directives(self) -> None:
     def _should_register_schema_directive(self, directive: object) -> bool:
         return True
 
+    def _should_include_type_in_sdl(self, graphql_type: "GraphQLNamedType") -> bool:
+        return graphql_type.name not in _PRIVATE_FEDERATION_TYPES
+
 
 def _get_entity_type(
     query: type[WithStrawberryObjectDefinition] | None,

strawberry/printer/printer.py

@@ -615,6 +615,7 @@ def print_schema(schema: BaseSchema) -> str:
         type_
         for type_name in sorted(type_map)
         if is_defined_type(type_ := type_map[type_name])
+        and schema._should_include_type_in_sdl(type_)
     ]
 
     types_printed = [_print_type(type_, schema, extras=extras) for type_ in types]
@@ -649,6 +650,9 @@ def _print_extra_types() -> Iterable[str]:
                 "GraphQLNamedType", schema.schema_converter.from_type(type_)
             )
 
+            if not schema._should_include_type_in_sdl(graphql_type):
+                continue
+
             # Skip types that are already part of the schema's type map, otherwise
             # they'd be printed twice (e.g. an enum used both as a regular type and
             # as a schema directive field), producing invalid SDL.

strawberry/schema/base.py

@@ -9,7 +9,7 @@
 if TYPE_CHECKING:
     from collections.abc import Iterable
 
-    from graphql import GraphQLError
+    from graphql import GraphQLError, GraphQLNamedType
 
     from strawberry.directive import StrawberryDirective
     from strawberry.schema.exception_handlers import ExceptionHandler
@@ -111,6 +111,10 @@ def get_directive_by_name(self, graphql_name: str) -> StrawberryDirective | None
     def as_str(self) -> str:
         raise NotImplementedError
 
+    @abstractmethod
+    def _should_include_type_in_sdl(self, graphql_type: GraphQLNamedType) -> bool:
+        raise NotImplementedError
+
     @staticmethod
     def remove_field_suggestion(error: GraphQLError) -> None:
         if (

strawberry/schema/schema.py

@@ -1427,6 +1427,9 @@ def as_str(self) -> str:
 
     __str__ = as_str
 
+    def _should_include_type_in_sdl(self, graphql_type: GraphQLNamedType) -> bool:
+        return True
+
     def introspect(self) -> dict[str, Any]:
         """Return the introspection query result for the current schema.
 

tests/federation/printer/test_additional_directives.py

@@ -43,8 +43,6 @@ class Query:
 
     union _Entity = FederatedType
 
-    scalar _FieldSet
-
     type _Service {
       sdl: String!
     }
@@ -101,8 +99,6 @@ class Query:
 
     union _Entity = FederatedType
 
-    scalar _FieldSet
-
     type _Service {
       sdl: String!
     }

tests/federation/printer/test_compose_directive.py

@@ -55,8 +55,6 @@ class Query:
 
     union _Entity = FederatedType
 
-    scalar _FieldSet
-
     type _Service {
       sdl: String!
     }
@@ -121,8 +119,6 @@ class Query:
 
     union _Entity = FederatedType
 
-    scalar _FieldSet
-
     type _Service {
       sdl: String!
     }

tests/federation/printer/test_entities.py

@@ -124,8 +124,6 @@ def top_products(self, first: int) -> list[Product]:  # pragma: no cover
 
         union _Entity = Product
 
-        scalar _FieldSet
-
         type _Service {
           sdl: String!
         }

tests/federation/printer/test_inaccessible.py

@@ -81,8 +81,6 @@ def top_products(
 
         union _Entity = Product
 
-        scalar _FieldSet
-
         type _Service {
           sdl: String!
         }

tests/federation/printer/test_interface.py

@@ -44,8 +44,6 @@ def top_products(self, first: int) -> list[Product]:  # pragma: no cover
 
         union _Entity = Product
 
-        scalar _FieldSet
-
         type _Service {
           sdl: String!
         }

tests/federation/printer/test_interface_object.py

@@ -28,8 +28,6 @@ class SomeInterface:
 
         union _Entity = SomeInterface
 
-        scalar _FieldSet
-
         type _Service {
           sdl: String!
         }