feat: support Annotated[AsyncSession, Depends(...)] in PathDependency and BodyDependency (#146)

src/fastapi_toolsets/dependencies.py

@@ -1,10 +1,12 @@
 """Dependency factories for FastAPI routes."""
 
 import inspect
+import typing
 from collections.abc import Callable
 from typing import Any, cast
 
 from fastapi import Depends
+from fastapi.params import Depends as DependsClass
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from .crud import CrudFactory
@@ -13,6 +15,15 @@ from .types import ModelType, SessionDependency
 __all__ = ["BodyDependency", "PathDependency"]
 
 
+def _unwrap_session_dep(session_dep: SessionDependency) -> Callable[..., Any]:
+    """Extract the plain callable from ``Annotated[AsyncSession, Depends(fn)]`` if needed."""
+    if typing.get_origin(session_dep) is typing.Annotated:
+        for arg in typing.get_args(session_dep)[1:]:
+            if isinstance(arg, DependsClass):
+                return arg.dependency
+    return session_dep
+
+
 def PathDependency(
     model: type[ModelType],
     field: Any,
@@ -44,6 +55,7 @@ def PathDependency(
         ): ...
         ```
     """
+    session_callable = _unwrap_session_dep(session_dep)
     crud = CrudFactory(model)
     name = (
         param_name
@@ -53,7 +65,7 @@ def PathDependency(
     python_type = field.type.python_type
 
     async def dependency(
-        session: AsyncSession = Depends(session_dep), **kwargs: Any
+        session: AsyncSession = Depends(session_callable), **kwargs: Any
     ) -> ModelType:
         value = kwargs[name]
         return await crud.get(session, filters=[field == value])
@@ -70,7 +82,7 @@ def PathDependency(
                     "session",
                     inspect.Parameter.KEYWORD_ONLY,
                     annotation=AsyncSession,
-                    default=Depends(session_dep),
+                    default=Depends(session_callable),
                 ),
             ]
         ),
@@ -112,11 +124,12 @@ def BodyDependency(
         ): ...
         ```
     """
+    session_callable = _unwrap_session_dep(session_dep)
     crud = CrudFactory(model)
     python_type = field.type.python_type
 
     async def dependency(
-        session: AsyncSession = Depends(session_dep), **kwargs: Any
+        session: AsyncSession = Depends(session_callable), **kwargs: Any
     ) -> ModelType:
         value = kwargs[body_field]
         return await crud.get(session, filters=[field == value])
@@ -133,7 +146,7 @@ def BodyDependency(
                     "session",
                     inspect.Parameter.KEYWORD_ONLY,
                     annotation=AsyncSession,
-                    default=Depends(session_dep),
+                    default=Depends(session_callable),
                 ),
             ]
         ),