Update JSONRenderer to render a null response when data=None

[kltdwrds]

Description

Fixes #6026

[rpkilby]

A test to verify the behavior would be required for acceptance.

[kltdwrds]

@rpkilby updated to fix the failures and add additional coverage

[novarac23]

+1

[rpkilby]

I'm wondering if it's more appropriate for the response object to handle 204/304 empty content. i.e., this behavior is universal across all content types, not just application/json.

[MattBlack85]

correct me if I'm wrong but there is no obligation to return some content on any status code, if this is going through how am I supposed to return an empty content for status codes other than 204? While for this case is enough to pass {} when returning a response to get rid of the error on ajax?

from jsonapi spec:
A JSON object MUST be at the root of every JSON API request and response *containing data*

[tomchristie]

Closing as per #6026.
This is one of those cases where there two different sets of behavior that could equally well be desired. I'd rather we leave the behavior as it currently is, and have return Response() indicate that an empty response should be returned with no content or content-type set.