Dependency injection

[abusquets]

I know that this might be more of a FastAPI question because Depends is from FastAPI, but I'll try anyway.
I'd like to pass a repository instance as a dependency created by a DI (Dependency Injection) container.

The code is:

@router.subscriber(task_queue, task_exchange, retry=False, no_ack=True)
async def handle_event(
    input: MonitorDataInDTO,
    msg: RabbitMessage,
    monitor_data_repository: Annotated[
        AbstractMonitorDataRepository, Depends(
            lambda: AppContainer().monitor_data_repository
        )
    ],
    logger: Logger,
) -> None:

But I have this error:

exam-guard-api            |   File "/app/app/asgi.py", line 11, in <module>
exam-guard-api            |     from exam_guard.adapters.api.broker.router import(
exam-guard-api            |   File "/app/exam_guard/adapters/api/broker/router.py", line 83, in <module>
exam-guard-api            |     @router.subscriber(task_queue, task_exchange, retry=False, no_ack=True)
exam-guard-api            |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/faststream/broker/fastapi/router.py", line 261, in decorator
exam-guard-api            |     return self._add_api_mq_route(
exam-guard-api            |            ^^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/faststream/broker/fastapi/router.py", line 219, in _add_api_mq_route
exam-guard-api            |     route = StreamRoute[MsgType, P_HandlerParams, T_HandlerReturn](
exam-guard-api            |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/usr/local/lib/python3.12/typing.py", line 1140, in __call__
exam-guard-api            |     result = self.__origin__(*args, **kwargs)
exam-guard-api            |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/faststream/broker/fastapi/route.py", line 80, in __init__
exam-guard-api            |     dependent = get_fastapi_native_dependant(
exam-guard-api            |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/faststream/broker/fastapi/get_dependant.py", line 35, in get_fastapi_native_dependant
exam-guard-api            |     dependent = get_dependant(
exam-guard-api            |                 ^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/fastapi/dependencies/utils.py", line 261, in get_dependant
exam-guard-api            |     type_annotation, depends, param_field = analyze_param(
exam-guard-api            |                                             ^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/fastapi/dependencies/utils.py", line 444, in analyze_param
exam-guard-api            |     field = create_response_field(
exam-guard-api            |             ^^^^^^^^^^^^^^^^^^^^^^
exam-guard-api            |   File "/srv/venv/lib/python3.12/site-packages/fastapi/utils.py", line 101, in create_response_field
exam-guard-api            |     raise fastapi.exceptions.FastAPIError(
exam-guard-api            | fastapi.exceptions.FastAPIError: Invalid args for response field! Hint: check that typing.Annotated[exam_guard.domain.ports.repositories.monitor_data.AbstractMonitorDataRepository, Depends(<lambda>)] is a valid Pydantic field type. If you are using a return type annotation that is not a valid Pydantic field (e.g. Union[Response, dict, None]) you can disable generating the response model from the type annotation with the path operation decorator parameter response_model=None. Read more: https://fastapi.tiangolo.com/tutorial/response-model/

I've tried a lot of options without success. Can anyone help me?

[Lancetnik]

I just can advice you to take a look at this project: https://github.com/Tishka17/deseos17/blob/master/src/deseos17/main/web.py#L60

It is a good example, how FastAPI Depends can be cooked (and how bad they are as well)

[abusquets]

Thanks a lot for your quick reply. I'll take a look.

[abusquets]

It works, I've used Depends from FastAPI because the Depends from faststream requires a dependency, but It works.
Thanks a lot.

[abusquets]

If anyone is interested, my implementation can be found in:
https://github.com/abusquets/exam-guard/blob/develop/src/app/asgi.py#L39
https://github.com/abusquets/exam-guard/blob/develop/src/exam_guard/adapters/api/broker/router.py#L85