Allow schema = None. Deprecate exclude_from_schema

[carltongibson]

The PR allows setting schema = None to exclude APIView subclasses from schema generation.

For function based views use @schema(None).

It deprecates exclude_from_schema on APIView and the exclude_from_schema argument to api_view.

[tomchristie]

"is pending deprecation"

[carltongibson]

@rpkilby I'm getting console noise in the test run from this. (Well from the call site but...)

tests/test_schemas.py ............/Users/carlton/Documents/Django-Stack/django-rest-framework/rest_framework/decorators.py:83: PendingDeprecationWarning: The `exclude_from_schema` argument to `api_view` is deprecated. Use the `schema` decorator instead, passing `None`.
  PendingDeprecationWarning
/Users/carlton/Documents/Django-Stack/django-rest-framework/rest_framework/schemas/generators.py:156: PendingDeprecationWarning: OldFashjonedExcludedView. The `APIView.exclude_from_schema` is deprecated. Set `schema = None` instead
  warnings.warn(msg, PendingDeprecationWarning)
....
tests/test_serializer.py .........................................

Can you advise on the best way to keep that quiet? Ta!

[tomchristie]

Not sure we need to test this. Don't believe that we've done so when deprecating other bits of API.

[carltongibson]

django-rest-framework/rest_framework/filters.py

Lines 48 to 52 in efff9ff

	warnings.warn(
	"The built in 'rest_framework.filters.FilterSet' is deprecated. "
	"You should use 'django_filters.rest_framework.FilterSet' instead.",
	DeprecationWarning, stacklevel=2
	)

and

django-rest-framework/tests/test_filters.py

Lines 172 to 185 in efff9ff

	@unittest.skipUnless(django_filters, 'django-filter not installed')
	def test_backend_deprecation(self):
	with warnings.catch_warnings(record=True) as w:
	warnings.simplefilter("always")
	view = FilterFieldsRootView.as_view()
	request = factory.get('/')
	response = view(request).render()
	assert response.status_code == status.HTTP_200_OK
	assert response.data == self.data
	self.assertTrue(issubclass(w[-1].category, DeprecationWarning))
	self.assertIn("'rest_framework.filters.DjangoFilterBackend' is deprecated.", str(w[-1].message))

It's something @rpkilby always puts in. I thought, Why not? 🙂

[rpkilby]

It looks like pytest.warns isn't recommended for deprecation warnings, as it doesn't capture output.
ach... I completely misread the docs. Either way, the below section sufficiently explains how to test deprecation warnings.

https://docs.pytest.org/en/latest/warnings.html#ensuring-function-triggers

[carltongibson]

@rpkilby OK. Thanks. I read that too but was still getting the noise...

1. I went with pytest.warns(PendingDeprecationWarning) because (for me) pytest.deprecated_call() failed with DID NOT WARN. No ideas why that wasn't working.
2. Despite the noise locally for me, this is not appearing in the travis run — so it must be my local setup.

(There is plenty of noise from py.test in travis but I assume that'll disappear with time.)

Lets call this done. Thanks for the input!

@tomchristie I think we're good to go.

[rpkilby]

Despite the noise locally for me, this is not appearing in the travis run — so it must be my local setup.

No noise when running the tests on my machine, so that would make sense.

[carltongibson]

Milestoned for 3.6.5. I'll convert that to 3.7 next week and begin putting together a release.

[tomchristie]

@carltongibson Looks good. 👍