✨ Add parameter dependencies to path operation decorators and include_router (#235)

* ✨ Implement dependencies in decorator and .include_router

* 📝 Add docs for parameter dependencies

* ✅ Add tests for dependencies parameter

* 🔥 Remove debugging prints in tests

* 📝 Update release notes

fastapi/applications.py

@@ -3,6 +3,7 @@ from typing import Any, Callable, Dict, List, Optional, Type, Union
 from fastapi import routing
 from fastapi.openapi.docs import get_redoc_html, get_swagger_ui_html
 from fastapi.openapi.utils import get_openapi
+from fastapi.params import Depends
 from pydantic import BaseModel
 from starlette.applications import Starlette
 from starlette.exceptions import ExceptionMiddleware, HTTPException
@@ -111,6 +112,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -128,6 +130,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -147,6 +150,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -165,6 +169,7 @@ class FastAPI(Starlette):
                 response_model=response_model,
                 status_code=status_code,
                 tags=tags or [],
+                dependencies=dependencies or [],
                 summary=summary,
                 description=description,
                 response_description=response_description,
@@ -186,10 +191,15 @@ class FastAPI(Starlette):
         *,
         prefix: str = "",
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         responses: Dict[Union[int, str], Dict[str, Any]] = None,
     ) -> None:
         self.router.include_router(
-            router, prefix=prefix, tags=tags, responses=responses or {}
+            router,
+            prefix=prefix,
+            tags=tags,
+            dependencies=dependencies,
+            responses=responses or {},
         )
 
     def get(
@@ -199,6 +209,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -214,6 +225,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -232,6 +244,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -247,6 +260,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -265,6 +279,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -280,6 +295,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -298,6 +314,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -313,6 +330,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -331,6 +349,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -346,6 +365,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -364,6 +384,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -379,6 +400,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -397,6 +419,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -412,6 +435,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -430,6 +454,7 @@ class FastAPI(Starlette):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -445,6 +470,7 @@ class FastAPI(Starlette):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,

fastapi/dependencies/utils.py

@@ -52,7 +52,7 @@ sequence_types = (list, set, tuple)
 sequence_shape_to_type = {Shape.LIST: list, Shape.SET: set, Shape.TUPLE: tuple}
 
 
-def get_sub_dependant(
+def get_param_sub_dependant(
     *, param: inspect.Parameter, path: str, security_scopes: List[str] = None
 ) -> Dependant:
     depends: params.Depends = param.default
@@ -60,6 +60,30 @@ def get_sub_dependant(
         dependency = depends.dependency
     else:
         dependency = param.annotation
+    return get_sub_dependant(
+        depends=depends,
+        dependency=dependency,
+        path=path,
+        name=param.name,
+        security_scopes=security_scopes,
+    )
+
+
+def get_parameterless_sub_dependant(*, depends: params.Depends, path: str) -> Dependant:
+    assert callable(
+        depends.dependency
+    ), "A parameter-less dependency must have a callable dependency"
+    return get_sub_dependant(depends=depends, dependency=depends.dependency, path=path)
+
+
+def get_sub_dependant(
+    *,
+    depends: params.Depends,
+    dependency: Callable,
+    path: str,
+    name: str = None,
+    security_scopes: List[str] = None,
+) -> Dependant:
     security_requirement = None
     security_scopes = security_scopes or []
     if isinstance(depends, params.Security):
@@ -73,7 +97,7 @@ def get_sub_dependant(
             security_scheme=dependency, scopes=use_scopes
         )
     sub_dependant = get_dependant(
-        path=path, call=dependency, name=param.name, security_scopes=security_scopes
+        path=path, call=dependency, name=name, security_scopes=security_scopes
     )
     if security_requirement:
         sub_dependant.security_requirements.append(security_requirement)
@@ -111,7 +135,7 @@ def get_dependant(
     for param_name in signature_params:
         param = signature_params[param_name]
         if isinstance(param.default, params.Depends):
-            sub_dependant = get_sub_dependant(
+            sub_dependant = get_param_sub_dependant(
                 param=param, path=path, security_scopes=security_scopes
             )
             dependant.dependencies.append(sub_dependant)
@@ -277,8 +301,8 @@ async def solve_dependencies(
             solved = await sub_dependant.call(**sub_values)
         else:
             solved = await run_in_threadpool(sub_dependant.call, **sub_values)
-        assert sub_dependant.name is not None, "Subdependants always have a name"
-        values[sub_dependant.name] = solved
+        if sub_dependant.name is not None:
+            values[sub_dependant.name] = solved
     path_values, path_errors = request_params_to_args(
         dependant.path_params, request.path_params
     )

fastapi/routing.py

@@ -5,7 +5,12 @@ from typing import Any, Callable, Dict, List, Optional, Type, Union
 
 from fastapi import params
 from fastapi.dependencies.models import Dependant
-from fastapi.dependencies.utils import get_body_field, get_dependant, solve_dependencies
+from fastapi.dependencies.utils import (
+    get_body_field,
+    get_dependant,
+    get_parameterless_sub_dependant,
+    solve_dependencies,
+)
 from fastapi.encoders import jsonable_encoder
 from pydantic import BaseConfig, BaseModel, Schema
 from pydantic.error_wrappers import ErrorWrapper, ValidationError
@@ -101,6 +106,7 @@ class APIRoute(routing.Route):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -135,6 +141,7 @@ class APIRoute(routing.Route):
             self.response_field = None
         self.status_code = status_code
         self.tags = tags or []
+        self.dependencies = dependencies or []
         self.summary = summary
         self.description = description or inspect.cleandoc(self.endpoint.__doc__ or "")
         self.response_description = response_description
@@ -175,6 +182,10 @@ class APIRoute(routing.Route):
             endpoint
         ), f"An endpoint must be a function or method"
         self.dependant = get_dependant(path=path, call=self.endpoint)
+        for depends in self.dependencies[::-1]:
+            self.dependant.dependencies.insert(
+                0, get_parameterless_sub_dependant(depends=depends, path=path)
+            )
         self.body_field = get_body_field(dependant=self.dependant, name=self.name)
         self.app = request_response(
             get_app(
@@ -196,6 +207,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -213,6 +225,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -233,6 +246,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -251,6 +265,7 @@ class APIRouter(routing.Router):
                 response_model=response_model,
                 status_code=status_code,
                 tags=tags or [],
+                dependencies=dependencies or [],
                 summary=summary,
                 description=description,
                 response_description=response_description,
@@ -272,6 +287,7 @@ class APIRouter(routing.Router):
         *,
         prefix: str = "",
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         responses: Dict[Union[int, str], Dict[str, Any]] = None,
     ) -> None:
         if prefix:
@@ -290,6 +306,7 @@ class APIRouter(routing.Router):
                     response_model=route.response_model,
                     status_code=route.status_code,
                     tags=(route.tags or []) + (tags or []),
+                    dependencies=(dependencies or []) + (route.dependencies or []),
                     summary=route.summary,
                     description=route.description,
                     response_description=route.response_description,
@@ -321,6 +338,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -336,6 +354,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -355,6 +374,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -370,6 +390,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -389,6 +410,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -404,6 +426,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -423,6 +446,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -438,6 +462,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -457,6 +482,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -472,6 +498,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -491,6 +518,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -506,6 +534,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -525,6 +554,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -540,6 +570,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,
@@ -559,6 +590,7 @@ class APIRouter(routing.Router):
         response_model: Type[BaseModel] = None,
         status_code: int = 200,
         tags: List[str] = None,
+        dependencies: List[params.Depends] = None,
         summary: str = None,
         description: str = None,
         response_description: str = "Successful Response",
@@ -574,6 +606,7 @@ class APIRouter(routing.Router):
             response_model=response_model,
             status_code=status_code,
             tags=tags or [],
+            dependencies=dependencies or [],
             summary=summary,
             description=description,
             response_description=response_description,