Dependency overriding: validation error

[jonathanmach]

Hi!

I have the following experiment, which works exactly as expected 🎉 :
Both webhooks_service and body get injected 👍

# main.py

@webhooks_api.route("/exp2", methods=["POST"])
@inject
def my_webhook2(
    webhooks_service: WebhookService = Depends(get_webhook_service),
    body: WebhookRequest = Validate(),
):
    webhooks_service.process_webhook(body.payload)
    return "Webhook processed successfully"

However, during tests, when trying to override the get_webhook_service dependency:

class FakeWebhookService(WebhookService):
    def process_webhook(self, payload):
        print("Fake processing webhook:", payload)


def get_fake_webhook_service():
    return FakeWebhookService()


@pytest.fixture
def test_app():
    flask_app = create_app()

    # Override the dependency
    dependency_provider.override(get_webhook_service, get_fake_webhook_service)
    # or
    # dependency_provider.dependency_overrides[original_dependency] = override_dependency

    with flask_app.test_client() as test_client:
        yield test_client


def test_dependency_overriding_exp2(test_app):
    # Exp2: Uses Annotated
    res = test_app.post("/exp2", json={"payload": {"foo": "bar"}})
    assert res.status_code == 200, res.data

I get the following error:

      Error: pydantic_core._pydantic_core.ValidationError: 1 validation error for my_webhook2
      webhooks_service
      Input should be an instance of WebhookService [type=is_instance_of, input_value=<test_app_3_fastdepends.g...bject at 0xffff9bc4eaa0>, input_type=get_fake_webhook_service.<locals>.FakeWebhookService]
      For further information visit https://errors.pydantic.dev/2.9/v/is_instance_of

NB: I noticed that the same issue doesn't happen on FastAPI.

[mr-mapache]

Hi! I was having the similar issues with pytest. Try disabling automatic casting from inject during testing, I don't know why but it did the job for me.