Server returning "500: Internal Server Error" when an internal error occurs.

[0xmadumere]

is there any way to override this behavior and pass a custom handler that runs when there is an internal server error?

[Dreamsorcerer]

Have you been through the tutorial?

Your question is vague, but I assume you want the middleware in there:
https://demos.aiohttp.org/en/latest/tutorial.html#middlewares

[0xmadumere]

I already have a middleware, the middleware doesnt catch internal server errors, like attribute errors e.g
Missing return statement on request handler
Traceback (most recent call last):
File "C:\Users\user\AppData\Local\Programs\Python\Python313\Lib\site-packages\aiohttp\web_protocol.py", line 705, in finish_response
prepare_meth = resp.prepare
^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'prepare'

it then proceeds to send 500: Internal Server Error to the client, and i dont want it do that whenever an internal error occurs

[Dreamsorcerer]

No, I don't think you can customise the response if there's a failure outside of the middleware's control.

Generally, you shouldn't be getting exceptions at that level, as that seems like a bug in aiohttp.
Any chance you can figure out a reproducer for that exception?

edit: Missed the line about missing return statement.

[Dreamsorcerer]

Looking through the code, my guess is that your handler returned None instead of a Response. I'd assume you test any endpoints first, which should reduce the chance of such a 500 error happening in production. But, we could maybe validate the type earlier to raise an exception into the middleware...

[Dreamsorcerer]

Thinking through it, I think we'd have to create a wrapper function around the handler and every middleware to achieve that, which is probably too much overhead to add to the critical path. Instead, I'd just suggest using a type checker on your code which would enforce that you don't return None in a handler.

[0xmadumere]

yh the return None was added deliberately by me to trigger the internal server error, so that I could capture the response it sends to the client when an internal error occurs, but anyway ive ended up just manually editing the source code for the finish_response and handle_error function in the the RequestHandler class to remove that functionality, I just wanted to find out if there was any already made endpoints that would allow me to do this. Thank you for your feedback nonetheless!