parametrize component registry identity #1288

drf_spectacular/contrib/pydantic.py

@@ -23,6 +23,7 @@ def get_name(self, auto_schema, direction):
         # of the entry model, we simply use the class name as string for object. This hack may
         # create false positive warnings, so turn it off. However, this may suppress correct
         # warnings involving the entry class.
+        # TODO suppression may be migrated to new ComponentIdentity system
         set_override(self.target, 'suppress_collision_warning', True)
         return self.target.__name__
 

drf_spectacular/contrib/rest_framework_dataclasses.py

@@ -1,6 +1,8 @@
+from typing import Any
+
 from drf_spectacular.drainage import get_override, has_override
 from drf_spectacular.extensions import OpenApiSerializerExtension
-from drf_spectacular.plumbing import get_doc
+from drf_spectacular.plumbing import ComponentIdentity, get_doc
 from drf_spectacular.utils import Direction
 
 
@@ -18,6 +20,9 @@ def get_name(self):
             return get_override(self.target.dataclass_definition.dataclass_type, 'component_name')
         return self.target.dataclass_definition.dataclass_type.__name__
 
+    def get_identity(self, auto_schema, direction: Direction) -> Any:
+        return ComponentIdentity(self.target.dataclass_definition.dataclass_type)
+
     def strip_library_doc(self, schema):
         """Strip the DataclassSerializer library documentation from the schema."""
         from rest_framework_dataclasses.serializers import DataclassSerializer

drf_spectacular/contrib/rest_polymorphic.py

@@ -1,7 +1,8 @@
 from drf_spectacular.drainage import warn
 from drf_spectacular.extensions import OpenApiSerializerExtension
 from drf_spectacular.plumbing import (
-    ResolvedComponent, build_basic_type, build_object_type, is_patched_serializer,
+    ComponentIdentity, ResolvedComponent, build_basic_type, build_object_type,
+    is_patched_serializer,
 )
 from drf_spectacular.settings import spectacular_settings
 from drf_spectacular.types import OpenApiTypes
@@ -25,7 +26,7 @@ def map_serializer(self, auto_schema, direction):
                 component = ResolvedComponent(
                     name=auto_schema._get_serializer_name(sub_serializer, direction),
                     type=ResolvedComponent.SCHEMA,
-                    object='virtual'
+                    object=ComponentIdentity('virtual')
                 )
             typed_component = self.build_typed_component(
                 auto_schema=auto_schema,

drf_spectacular/extensions.py

@@ -68,6 +68,10 @@ def get_name(self, auto_schema: 'AutoSchema', direction: Direction) -> Optional[
         """ return str for overriding default name extraction """
         return None
 
+    def get_identity(self, auto_schema: 'AutoSchema', direction: Direction) -> Any:
+        """ return anything to compare instances of target. Target will be used by default. """
+        return None
+
     def map_serializer(self, auto_schema: 'AutoSchema', direction: Direction) -> _SchemaType:
         """ override for customized serializer mapping """
         return auto_schema._map_serializer(self.target_class, direction, bypass_extensions=True)

drf_spectacular/openapi.py

@@ -1478,12 +1478,13 @@ def _get_response_for_code(self, serializer, status_code, media_types=None, dire
                 and is_serializer(serializer)
                 and (not is_list_serializer(serializer) or is_serializer(serializer.child))
             ):
-                paginated_name = self.get_paginated_name(self._get_serializer_name(serializer, "response"))
                 component = ResolvedComponent(
-                    name=paginated_name,
+                    name=self.get_paginated_name(self._get_serializer_name(serializer, 'response')),
                     type=ResolvedComponent.SCHEMA,
                     schema=paginator.get_paginated_response_schema(schema),
-                    object=serializer.child if is_list_serializer(serializer) else serializer,
+                    object=self.get_serializer_identity(
+                        serializer.child if is_list_serializer(serializer) else serializer, 'response'
+                    )
                 )
                 self.registry.register_on_missing(component)
                 schema = component.ref
@@ -1556,7 +1557,17 @@ def _get_response_headers_for_code(self, status_code, direction='response') -> _
 
         return result
 
+    def get_serializer_identity(self, serializer, direction: Direction) -> Any:
+        serializer_extension = OpenApiSerializerExtension.get_match(serializer)
+        if serializer_extension:
+            identity = serializer_extension.get_identity(self, direction)
+            if identity is not None:
+                return identity
+
+        return serializer
+
     def get_serializer_name(self, serializer: serializers.Serializer, direction: Direction) -> str:
+        """ override this for custom behaviour """
         return serializer.__class__.__name__
 
     def _get_serializer_name(self, serializer, direction, bypass_extensions=False) -> str:
@@ -1612,7 +1623,7 @@ def resolve_serializer(
             component = ResolvedComponent(
                 name=self._get_serializer_name(serializer, direction, bypass_extensions),
                 type=ResolvedComponent.SCHEMA,
-                object=serializer,
+                object=self.get_serializer_identity(serializer, direction),
             )
             if component in self.registry:
                 return self.registry[component]  # return component with schema

drf_spectacular/plumbing.py

@@ -723,6 +723,17 @@ def ref(self) -> _SchemaType:
         return {'$ref': f'#/components/{self.type}/{self.name}'}
 
 
+class ComponentIdentity:
+    """ A container class to make object/component comparison explicit """
+    def __init__(self, obj):
+        self.obj = obj
+
+    def __eq__(self, other):
+        if isinstance(other, ComponentIdentity):
+            return self.obj == other.obj
+        return self.obj == other
+
+
 class ComponentRegistry:
     def __init__(self) -> None:
         self._components: Dict[Tuple[str, str], ResolvedComponent] = {}
@@ -746,17 +757,25 @@ def __contains__(self, component):
 
         query_obj = component.object
         registry_obj = self._components[component.key].object
-        query_class = query_obj if inspect.isclass(query_obj) else query_obj.__class__
-        registry_class = query_obj if inspect.isclass(registry_obj) else registry_obj.__class__
+
+        if isinstance(query_obj, ComponentIdentity) or inspect.isclass(query_obj):
+            query_id = query_obj
+        else:
+            query_id = query_obj.__class__
+
+        if isinstance(registry_obj, ComponentIdentity) or inspect.isclass(registry_obj):
+            registry_id = registry_obj
+        else:
+            registry_id = registry_obj.__class__
 
         suppress_collision_warning = (
-            get_override(registry_class, 'suppress_collision_warning', False)
-            or get_override(query_class, 'suppress_collision_warning', False)
+            get_override(registry_id, 'suppress_collision_warning', False)
+            or get_override(query_id, 'suppress_collision_warning', False)
         )
-        if query_class != registry_class and not suppress_collision_warning:
+        if query_id != registry_id and not suppress_collision_warning:
             warn(
                 f'Encountered 2 components with identical names "{component.name}" and '
-                f'different classes {query_class} and {registry_class}. This will very '
+                f'different identities {query_id} and {registry_id}. This will very '
                 f'likely result in an incorrect schema. Try renaming one.'
             )
         return True

tests/contrib/test_rest_framework_dataclasses.py

@@ -90,3 +90,49 @@ def custom_name_via_serializer_decoration(request):
         generate_schema(None, patterns=urlpatterns),
         'tests/contrib/test_rest_framework_dataclasses.yml'
     )
+
+
+@pytest.mark.contrib('rest_framework_dataclasses')
+@pytest.mark.skipif(sys.version_info < (3, 7), reason='dataclass required by package')
+def test_rest_framework_dataclasses_class_reuse(no_warnings):
+    from dataclasses import dataclass
+
+    from rest_framework_dataclasses.serializers import DataclassSerializer
+
+    @dataclass
+    class Person:
+        name: str
+        age: int
+
+    @dataclass
+    class Party:
+        person: Person
+        num_persons: int
+
+    class PartySerializer(DataclassSerializer[Party]):
+        class Meta:
+            dataclass = Party
+
+    class PersonSerializer(DataclassSerializer[Person]):
+        class Meta:
+            dataclass = Person
+
+    @extend_schema(responses=PartySerializer)
+    @api_view()
+    def party(request):
+        pass  # pragma: no cover
+
+    @extend_schema(responses=PersonSerializer)
+    @api_view()
+    def person(request):
+        pass  # pragma: no cover
+
+    urlpatterns = [
+        path('party', person),
+        path('person', party),
+    ]
+
+    schema = generate_schema(None, patterns=urlpatterns)
+    # just existence is enough to check since its about no_warnings
+    assert 'Person' in schema['components']['schemas']
+    assert 'Party' in schema['components']['schemas']

tests/test_warnings.py

@@ -49,7 +49,7 @@ class X2Viewset(mixins.ListModelMixin, viewsets.GenericViewSet):
     generate_schema(None, patterns=router.urls)
 
     stderr = capsys.readouterr().err
-    assert 'Encountered 2 components with identical names "X" and different classes' in stderr
+    assert 'Encountered 2 components with identical names "X" and different identities' in stderr
 
 
 def test_owned_serializer_naming_override_with_ref_name_collision(warnings):