Fix the format_errors bug when response data is None

[ericinfins]

Fixes #

Related to the PR: #1121
Add the test case to support it

Description of the Change

Fix: TypeError: object of type 'NoneType' has no len()

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS

[sliverc]

Thanks for following up on this. I will take a look at it at some point and will give you feedback. Just writing to let you know that I saw it.

[sliverc]

I have finally got around to take a look at this. Great to see how this can be reproduced by using vanilla DRF classes.

It is though as I expected that this fix does avoid the exception, however the output of the fix is not JSON:API compliant. It simply returns

{
  "errors": None
}

but the value of errors needs to be a list and each error object must at least have one member. I think the easiest is to add a single error object with the status code as a string.