Improve dependencies typing

fastapi_users/authentication/authenticator.py

@@ -9,6 +9,7 @@ from fastapi_users import models
 from fastapi_users.authentication.backend import AuthenticationBackend
 from fastapi_users.authentication.strategy import Strategy
 from fastapi_users.manager import BaseUserManager, UserManagerDependency
+from fastapi_users.types import DependencyCallable
 
 INVALID_CHARS_PATTERN = re.compile(r"[^0-9a-zA-Z_]")
 INVALID_LEADING_CHARS_PATTERN = re.compile(r"^[^a-zA-Z_]+")
@@ -30,7 +31,7 @@ class DuplicateBackendNamesError(Exception):
     pass
 
 
-EnabledBackendsDependency = Callable[..., Sequence[AuthenticationBackend]]
+EnabledBackendsDependency = DependencyCallable[Sequence[AuthenticationBackend]]
 
 
 class Authenticator:

fastapi_users/authentication/backend.py

@@ -1,4 +1,4 @@
-from typing import Any, Callable, Generic
+from typing import Any, Generic
 
 from fastapi import Response
 
@@ -11,6 +11,7 @@ from fastapi_users.authentication.transport import (
     Transport,
     TransportLogoutNotSupportedError,
 )
+from fastapi_users.types import DependencyCallable
 
 
 class AuthenticationBackend(Generic[models.UC, models.UD]):
@@ -32,7 +33,7 @@ class AuthenticationBackend(Generic[models.UC, models.UD]):
         self,
         name: str,
         transport: Transport,
-        get_strategy: Callable[..., Strategy[models.UC, models.UD]],
+        get_strategy: DependencyCallable[Strategy[models.UC, models.UD]],
     ):
         self.name = name
         self.transport = transport

fastapi_users/db/base.py

@@ -1,8 +1,9 @@
-from typing import Callable, Generic, Optional, Type
+from typing import Generic, Optional, Type
 
 from pydantic import UUID4
 
 from fastapi_users.models import UD
+from fastapi_users.types import DependencyCallable
 
 
 class BaseUserDatabase(Generic[UD]):
@@ -42,4 +43,4 @@ class BaseUserDatabase(Generic[UD]):
         raise NotImplementedError()
 
 
-UserDatabaseDependency = Callable[..., BaseUserDatabase[UD]]
+UserDatabaseDependency = DependencyCallable[BaseUserDatabase[UD]]

fastapi_users/manager.py

@@ -1,4 +1,4 @@
-from typing import Any, Callable, Dict, Generic, Optional, Type, Union
+from typing import Any, Dict, Generic, Optional, Type, Union
 
 import jwt
 from fastapi import Request
@@ -9,6 +9,7 @@ from fastapi_users import models, password
 from fastapi_users.db import BaseUserDatabase
 from fastapi_users.jwt import SecretType, decode_jwt, generate_jwt
 from fastapi_users.password import generate_password, get_password_hash
+from fastapi_users.types import DependencyCallable
 
 RESET_PASSWORD_TOKEN_AUDIENCE = "fastapi-users:reset"
 VERIFY_USER_TOKEN_AUDIENCE = "fastapi-users:verify"
@@ -555,4 +556,4 @@ class BaseUserManager(Generic[models.UC, models.UD]):
         return await self.user_db.update(user)
 
 
-UserManagerDependency = Callable[..., BaseUserManager[models.UC, models.UD]]
+UserManagerDependency = DependencyCallable[BaseUserManager[models.UC, models.UD]]

fastapi_users/types.py

@@ -0,0 +1,7 @@
+from typing import Callable, Coroutine, TypeVar, Union
+
+RETURN_TYPE = TypeVar("RETURN_TYPE")
+
+DependencyCallable = Callable[
+    ..., Union[RETURN_TYPE, Coroutine[None, None, RETURN_TYPE]]
+]

tests/test_authentication_authenticator.py

@@ -1,4 +1,4 @@
-from typing import AsyncGenerator, Callable, Generic, List, Optional, Sequence
+from typing import AsyncGenerator, Generic, List, Optional, Sequence
 
 import httpx
 import pytest
@@ -11,6 +11,7 @@ from fastapi_users.authentication.authenticator import DuplicateBackendNamesErro
 from fastapi_users.authentication.strategy import Strategy
 from fastapi_users.authentication.transport import Transport
 from fastapi_users.manager import BaseUserManager
+from fastapi_users.types import DependencyCallable
 from tests.conftest import UserDB
 
 
@@ -71,7 +72,7 @@ def get_test_auth_client(get_user_manager, get_test_client):
     async def _get_test_auth_client(
         backends: List[AuthenticationBackend],
         get_enabled_backends: Optional[
-            Callable[..., Sequence[AuthenticationBackend]]
+            DependencyCallable[Sequence[AuthenticationBackend]]
         ] = None,
     ) -> AsyncGenerator[httpx.AsyncClient, None]:
         app = FastAPI()

tests/test_authentication_backend.py

@@ -1,4 +1,4 @@
-from typing import Callable, Generic, Optional, Type
+from typing import Callable, Generic, Optional, Type, cast
 
 import pytest
 from fastapi import Response
@@ -56,5 +56,6 @@ def backend(
 @pytest.mark.asyncio
 @pytest.mark.authentication
 async def test_logout(backend: AuthenticationBackend, user: UserDB):
-    result = await backend.logout(backend.get_strategy(), user, "TOKEN", Response())
+    strategy = cast(Strategy, backend.get_strategy())
+    result = await backend.logout(strategy, user, "TOKEN", Response())
     assert result is None