add dataclasses callable and apply annotations more strictly

Added new parameter ``dataclasses_callable`` to both the
:class:`_orm.MappedAsDataclass` class as well as the
:meth:`_orm.registry.mapped_as_dataclass` method which allows an
alternative callable to Python ``dataclasses.dataclass`` to be used in
order to produce dataclasses. The use case here is to drop in Pydantic's
dataclass function instead. Adjustments have been made to the mixin support
added for :ticket:`9179` in version 2.0.1 so that the ``__annotations__``
collection of the mixin is rewritten to not include the
:class:`_orm.Mapped` container, in the same way as occurs with mapped
classes, so that the Pydantic dataclasses constructor is not exposed to
unknown types.

Fixes: #9266
Change-Id: Ia0fab6f20b93a5cb853799dcf1b70a0386837c14

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/decl_api.py b/lib/sqlalchemy/orm/decl_api.py
index d02012b86..f332d2964 100644
--- a/lib/sqlalchemy/orm/decl_api.py
+++ b/lib/sqlalchemy/orm/decl_api.py
@@ -593,6 +593,9 @@ class MappedAsDataclass(metaclass=DCTransformDeclarative):
         unsafe_hash: Union[_NoArg, bool] = _NoArg.NO_ARG,
         match_args: Union[_NoArg, bool] = _NoArg.NO_ARG,
         kw_only: Union[_NoArg, bool] = _NoArg.NO_ARG,
+        dataclass_callable: Union[
+            _NoArg, Callable[..., Type[Any]]
+        ] = _NoArg.NO_ARG,
     ) -> None:
         apply_dc_transforms: _DataclassArguments = {
             "init": init,
@@ -602,6 +605,7 @@ class MappedAsDataclass(metaclass=DCTransformDeclarative):
             "unsafe_hash": unsafe_hash,
             "match_args": match_args,
             "kw_only": kw_only,
+            "dataclass_callable": dataclass_callable,
         }
 
         current_transforms: _DataclassArguments
@@ -623,8 +627,11 @@ class MappedAsDataclass(metaclass=DCTransformDeclarative):
         super().__init_subclass__()
 
         if not _is_mapped_class(cls):
+            new_anno = (
+                _ClassScanMapperConfig._update_annotations_for_non_mapped_class
+            )(cls)
             _ClassScanMapperConfig._apply_dataclasses_to_any_class(
-                current_transforms, cls
+                current_transforms, cls, new_anno
             )
 
 
@@ -1569,6 +1576,7 @@ class registry:
         unsafe_hash: Union[_NoArg, bool] = ...,
         match_args: Union[_NoArg, bool] = ...,
         kw_only: Union[_NoArg, bool] = ...,
+        dataclass_callable: Union[_NoArg, Callable[..., Type[Any]]] = ...,
     ) -> Callable[[Type[_O]], Type[_O]]:
         ...
 
@@ -1583,6 +1591,9 @@ class registry:
         unsafe_hash: Union[_NoArg, bool] = _NoArg.NO_ARG,
         match_args: Union[_NoArg, bool] = _NoArg.NO_ARG,
         kw_only: Union[_NoArg, bool] = _NoArg.NO_ARG,
+        dataclass_callable: Union[
+            _NoArg, Callable[..., Type[Any]]
+        ] = _NoArg.NO_ARG,
     ) -> Union[Type[_O], Callable[[Type[_O]], Type[_O]]]:
         """Class decorator that will apply the Declarative mapping process
         to a given class, and additionally convert the class to be a
@@ -1608,6 +1619,7 @@ class registry:
                 "unsafe_hash": unsafe_hash,
                 "match_args": match_args,
                 "kw_only": kw_only,
+                "dataclass_callable": dataclass_callable,
             }
             _as_declarative(self, cls, cls.__dict__)
             return cls