only allow redirect_chain attribute in response when client sets the follow flag

[hoefling]

Signed-off-by: Oleg Hoefling [email protected]

I have made things!

This is #1252, reintroduced. Description copied for the sake of completeness:

The redirect_chain attribute was added in #1124. At runtime, the response only has this attribute set when the request was made with follow=True:

In [1]: from django.test import Client

In [2]: c = Client()

In [3]: c.get('/spam', follow=True).redirect_chain
Not Found: /spam
2022-11-12 15:42:28 [WARNING ] django.request :: Not Found: /spam
Out[3]: []

In [4]: c.get('/spam', follow=False).redirect_chain
Not Found: /spam
2022-11-12 15:42:33 [WARNING ] django.request :: Not Found: /spam
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Input In [4], in <cell line: 1>()
----> 1 c.get('/spam', follow=False).redirect_chain

AttributeError: 'HttpResponseNotFound' object has no attribute 'redirect_chain'

This PR replicates this behaviour.

Related issues

Refs #1252

[sobolevn]

The same is for all other overloads.

Do you agree?

[sobolevn]

I think we can remove this overload, it is the same as bool

[hoefling]

@sobolevn this will cause a false positive tho for the default value, e.g. Client().get('foo').response_chain will be inferred as existing since the follow: Literal[True] case matches and I can't put it behind the broader follow: bool case. The client_follow_flag test I added should also fail when the first override is deleted.

[intgr]

Hmm. Ordinarily you would remove the default value (= ...) from the argument in one of the overloads, like

@overload
def get(self, path: str, data: Any = ..., follow: Literal[True], secure: bool = ..., **extra: Any) -> _MonkeyPatchedWSGIResponseRedirect: ...
#                                         ^^^^^^^^^^^^^^^^^^^^^
@overload
def get(self, path: str, data: Any = ..., follow: bool = ..., secure: bool = ..., **extra: Any) -> _MonkeyPatchedWSGIResponse: ...

But here it's not allowed because it follows another argument with default data.

I'm not aware of any tricks to make it work. May indeed have to use 3 overloads.

[sobolevn]

Maybe we should allow bool? I think the main usecase for this is in unit-tests. They will be checked in all cases, but we can just make things harder for users by producing errors (and possibly false-positives).

[hoefling]

@sobolevn sorry, I cannot follow you. Or do you mean "not allow bool" instead? Only boolean literals?

[sobolevn]

Sorry :(

I mean that using bool should not produce this error. Because users will get a unittest failure if it is not True anyway. And I don't want to have false-positives in test code.

Is it better now? 😊