Keep original queryset on DjangoFilterConnectionField (#816)

* Keep original queryset on DjangoFilterConnectionField

The PR #796 broke DjangoFilterConnectionField making it always get the
raw queryset from the model to apply the filters in it.

This makes sure that the DjangoObjectType's .get_queryset is called,
keeping any filtering it might have made.

* Add regression test

graphene_django/filter/fields.py

@@ -55,10 +55,11 @@ class DjangoFilterConnectionField(DjangoConnectionField):
     def resolve_queryset(
         cls, connection, iterable, info, args, filtering_args, filterset_class
     ):
+        qs = super(DjangoFilterConnectionField, cls).resolve_queryset(
+            connection, iterable, info, args
+        )
         filter_kwargs = {k: v for k, v in args.items() if k in filtering_args}
-        return filterset_class(
-            data=filter_kwargs, queryset=iterable, request=info.context
-        ).qs
+        return filterset_class(data=filter_kwargs, queryset=qs, request=info.context).qs
 
     def get_queryset_resolver(self):
         return partial(

graphene_django/filter/tests/test_fields.py

@@ -756,6 +756,44 @@ def test_annotation_with_only():
     assert result.data == expected
 
 
+def test_node_get_queryset_is_called():
+    class ReporterType(DjangoObjectType):
+        class Meta:
+            model = Reporter
+            interfaces = (Node,)
+            filter_fields = ()
+
+        @classmethod
+        def get_queryset(cls, queryset, info):
+            return queryset.filter(first_name="b")
+
+    class Query(ObjectType):
+        all_reporters = DjangoFilterConnectionField(
+            ReporterType, reverse_order=Boolean()
+        )
+
+    Reporter.objects.create(first_name="b")
+    Reporter.objects.create(first_name="a")
+
+    schema = Schema(query=Query)
+    query = """
+        query NodeFilteringQuery {
+            allReporters(first: 10) {
+                edges {
+                    node {
+                        firstName
+                    }
+                }
+            }
+        }
+    """
+    expected = {"allReporters": {"edges": [{"node": {"firstName": "b"}}]}}
+
+    result = schema.execute(query)
+    assert not result.errors
+    assert result.data == expected
+
+
 def test_integer_field_filter_type():
     class PetType(DjangoObjectType):
         class Meta: