Fix support of typing.Any in GraphQL schema

apischema/graphql/resolvers.py

@@ -83,10 +83,6 @@ def __init__(
             pass_through_options,
         )
 
-    @property
-    def _factory(self) -> Callable[[type], SerializationMethod]:
-        raise NotImplementedError
-
     def enum(self, cls: Type[Enum]) -> SerializationMethod:
         return IDENTITY_METHOD
 

apischema/graphql/schema.py

@@ -77,11 +77,7 @@
     to_camel_case,
 )
 
-JsonScalar = graphql.GraphQLScalarType("JSON")
-if graphql.version_info >= (3, 1, 2):
-    JsonScalar.specified_by_url = (
-        "http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf"
-    )
+JSON_SCALAR = graphql.GraphQLScalarType("JSON")
 GRAPHQL_PRIMITIVE_TYPES = {
     int: graphql.GraphQLInt,
     float: graphql.GraphQLFloat,
@@ -229,7 +225,8 @@ def name_cache(
             name: Optional[str], description: Optional[str]
         ) -> graphql.GraphQLNonNull:
             if name is None:
-                return graphql.GraphQLNonNull(factory.factory(name, description))  # type: ignore
+                tp = factory.factory(name, description)  # type: ignore
+                return graphql.GraphQLNonNull(tp) if tp is not JSON_SCALAR else tp
             # Method is in cache key because scalar types will have the same method,
             # and then be shared by both visitors, while input/output types will have
             # their own cache entry.
@@ -306,7 +303,7 @@ def factory(
             name: Optional[str], description: Optional[str]
         ) -> graphql.GraphQLScalarType:
             if name is None:
-                return JsonScalar
+                return JSON_SCALAR
             else:
                 return graphql.GraphQLScalarType(name, description=description)
 
@@ -366,7 +363,7 @@ def factory(
             if name is not None:
                 return graphql.GraphQLScalarType(name, description=description)
             else:
-                return JsonScalar
+                return JSON_SCALAR
 
         return TypeFactory(factory)
 

docs/graphql/data_model_and_resolvers.md

@@ -103,8 +103,16 @@ Following the example of [type/field/method base schema](../json_schema.md#base-
 {!base_schema_parameter.py!}
 ```
 
+## Scalars
+
+`NewType` or non-object types annotated with `type_name`  will be translated in the GraphQL schema by a `scalar`. By the way, `Any` will automatically be translated to a `JSON` scalar, as it is deserialized from and serialized to JSON.
+
+```python
+{!scalar.py!}
+```
+
 ## ID type
-GraphQL `ID` has no precise specification and is defined according API needs; it can be a UUID or and ObjectId, etc.
+GraphQL `ID` has no precise specification and is defined according API needs; it can be a UUID or/and ObjectId, etc.
 
 `apischema.graphql_schema` has a parameter `id_types` which can be used to define which types will be marked as `ID` in the generated schema. Parameter value can be either a collection of types (each type will then be mapped to `ID` scalar), or a predicate returning if the given type must be marked as `ID`.
 
@@ -134,6 +142,7 @@ GraphQL `ID` has no precise specification and is defined according API needs; it
 
     If you use base64 encodeing and an ID type which is converted by *apischema* to a base64 str, you will get a double encoded base64 string
 
+
 ## Tagged unions
 
 !!! important

examples/scalar.py

@@ -0,0 +1,35 @@
+from dataclasses import dataclass
+from typing import Any
+from uuid import UUID
+
+from graphql.utilities import print_schema
+
+from apischema.graphql import graphql_schema
+
+
+@dataclass
+class Foo:
+    id: UUID
+    content: Any
+
+
+def foo() -> Foo | None:
+    ...
+
+
+schema = graphql_schema(query=[foo])
+schema_str = """\
+type Query {
+  foo: Foo
+}
+
+type Foo {
+  id: UUID!
+  content: JSON
+}
+
+scalar UUID
+
+scalar JSON
+"""
+assert print_schema(schema) == schema_str