Does _StreamingResponse correctly inherit Response

[whymatter]

I came across this discussion since we were affected by this change. While I understand that we can not expect aStreamingResponse I have another issue.

Disclaimer: Since I am not a 100% Python typing expert please correct me if I am wrong but my understanding is that a derived class should have all attributed that the base class publishes.

The _StreamingResponse inherits Response but does not call the super constructur, hence _StreamingResponse does not have the attributes that Response promises (e.g. body). Imho there are three possible solutions:

• Make body private _body. This hides it from external use (I dont think that is the way to go)
• Add body to _StreamingResponse e.g. by calling super
• Remove body from Response or extract another base class like BaseResponse that does not have body

[adriangb]

You're right that something is wrong with our response inheritance chain. I think we should just re-design it, before 1.0. @abersheeran has thought about this before and has a proposed solution.

I would be keep to accept a PR with the fix, ideally one that does the right thing but still tries to minimize breaking changes.

[abersheeran]

If you're interested, I have a code here that I think is a good inheritance of Response class. https://github.com/abersheeran/baize/blob/master/baize/asgi/responses.py