Filter backend schema inspector issue

[matiucarr]

Checklist

• [x] I have verified that that issue exists against the master branch of Django REST framework.
• [x] I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• [x] This is not a usage question. (Those should be directed to the discussion group instead.)
• [x] This cannot be dealt with as a third party library. (We prefer new functionality to be in the form of third party libraries where possible.)
• [x] I have reduced the issue to the simplest possible case.
• [ ] I have included a failing test as a pull request. (If you are unable to do so we can still accept the issue.)

Steps to reproduce

• Using django_restframework 3.7.3 in conjunction with django-filter 1.1.0 and django-rest-swagger 2.1.2
• configure a default filter backend as per the documentation in DRF and Djanjo-Filter or add it using the filter_backends attribute of the view.
• create a suitable filterset and add it to the view via the filter_class attribute.

Expected behavior

Filter options should render under the appropriate method in swagger, etc.

Actual behavior

• filter fields do not render in the swagger view, or the bvrowseable API.

a fix

• override action in the view class -this is silly but provided a clue

• change line 371 of restframework/schemas/inspectors.py to actually generate a lower case version of the method:

change

return method.lower in ["get", "put", "patch", "delete"]

to

return method.lower() in ["get", "put", "patch", "delete"]

[carltongibson]

Yep. That seems like a bug. (Wondering about test coverage there...)

@matiucarr If you're up for it we'd happily see a PR (with a small failing test) to address this.

Thanks for the report!

[D3X]

@carltongibson I've created a PR with a test and a fix here: #5613 Let me know if that test makes sense in your opinion.

[rpkilby]

Thanks @D3X!