422 is not reported despite setting `failed_request_status_codes`

[sentrivana]

How do you use Sentry?

Sentry Saas (sentry.io)

Version

2.9.0

Steps to Reproduce

From Discord:

Using Sentry with FastAPI, I'm initializing Sentry as follows:

failed_request_status_codes = [range(400, 600)]
sentry_sdk.init(
    integrations=[
        StarletteIntegration(failed_request_status_codes=failed_request_status_codes),
        FastApiIntegration(failed_request_status_codes=failed_request_status_codes),
    ],
    before_send=filter_transactions,
)

HTTPException raised directly or unexpected 500 errors are well reported to Sentry. However, 422 errors, where the request doesn't match the expected type, are not being sent to Sentry. How can I resolve this?

Expected Result

422s should be reported.

Actual Result

422s are not reported.

[antonpirker]

I did some digging.

This is the check if the error is in the range of error that should be captured: https://github.com/getsentry/sentry-python/blob/master/sentry_sdk/integrations/starlette.py#L222

In there we do hasattr(exp, "status_code").

In the case of a HTTP 422 exp is RequestValidationError([{'type': 'missing', 'loc': ('query', 'user'), 'msg': 'Field required', 'input': None, 'url': 'https://errors.pydantic.dev/2.8/v/missing'}]) which does not have a status_code

(in comparison if it is a HTTP 405 it is HTTPException(status_code=405, detail='Method Not Allowed'))

It is not an HTTPException but an ValidationError.

To capture this validation error we need to monkey patch another part of FastAPI that is not the ExceptionMiddleware but rather this handler: https://github.com/tiangolo/fastapi/blob/15130a3eb5080d8d457752a502167ddd44d79156/fastapi/exception_handlers.py#L20-L26

[antonpirker]

Long story short: there is no easy fix for that :-)