Dependency in Base class doesn't appear to materialize

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Example Code

from abc import ABC
from fastapi import Request
from core.repos import AuditRepo
class BaseUseCase(ABC):
    def __init__(self, req: Request, audit : AuditRepo = Depends()
        self.audit = audit
        self.req = req
    def handle(self):
        self.audit.record(self.req) # This line throws AttributeError
        self.execute()

class CancelOrder(BaseUseCase):
    def __init__(self, some_other_dependency: SomeRepo = Depends()):
        super().__init__()
        self.some_other_dependency = some_other_dependency

    def execute(self):
        print("Cancelling Order")
        self.some_other_dependency.do_something() # This works

Description

I’m stuck at a point where I need to use a common Dependency in the base class of all my usecases. For example, AuditTrail which needs to happen on all transactions.

To fulfil this requirement I set the audit as a dependency in the BaseUseCase class. However, when I call it on “self.audit.record()” it throws error: “AttributeError: ‘Depends’ object has no attribute ‘record’”

All other dependencies in CancelOrder work fine.

Am I doing something wrong here?

Operating System

macOS

Operating System Details

No response

FastAPI Version

0.70.0

Python Version

3.10.0

Additional Context

No response

[upeshphable]

@tiangolo Do you have any insights into this please. There is another issue somebody opened and it appears either we are missing the knowledge to use dependency in base class.

Another developer opened an issue: #4681

[upeshphable]

I saw another issue https://github.com/tiangolo/fastapi/issues/1105 which appeared to be similar but I can understand that the target function was not in the request path.