django-filter: resolve field along with lookup expression to properly resolve field

graphene_django/filter/tests/test_fields.py

@@ -877,7 +877,7 @@ def test_filter_filterset_based_on_mixin():
             filters = super(FilterSet, cls).get_filters()
             filters.update(
                 {
-                    "viewer__email__in": django_filters.CharFilter(
+                    "reporter__email__in": django_filters.CharFilter(
                         method="filter_email_in", field_name="reporter__email__in"
                     )
                 }
@@ -897,16 +897,11 @@ def test_filter_filterset_based_on_mixin():
             interfaces = (Node,)
 
     class NewArticleFilterNode(DjangoObjectType):
-        viewer = Field(NewReporterNode)
-
         class Meta:
             model = Article
             interfaces = (Node,)
             filterset_class = NewArticleFilter
 
-        def resolve_viewer(self, info):
-            return self.reporter
-
     class Query(ObjectType):
         all_articles = DjangoFilterConnectionField(NewArticleFilterNode)
 
@@ -939,11 +934,11 @@ def test_filter_filterset_based_on_mixin():
     query = (
         """
         query NodeFilteringQuery {
-            allArticles(viewer_Email_In: "%s") {
+            allArticles(reporter_Email_In: "%s") {
                 edges {
                     node {
                         headline
-                        viewer {
+                        reporter {
                             email
                         }
                     }
@@ -960,7 +955,7 @@ def test_filter_filterset_based_on_mixin():
                 {
                     "node": {
                         "headline": article_1.headline,
-                        "viewer": {"email": reporter_1.email},
+                        "reporter": {"email": reporter_1.email},
                     }
                 }
             ]

graphene_django/filter/utils.py

@@ -1,8 +1,36 @@
 import six
 
+from django.db.models.constants import LOOKUP_SEP
+from django.core.exceptions import FieldDoesNotExist
+from django.db.models.fields.related import ForeignObjectRel, RelatedField
 from .filterset import custom_filterset_factory, setup_filterset
 
 
+def get_field_parts_with_expression(model, query_expr):
+    """
+    Traverses the model with a given query expression,
+    returns the found fields along the path and the remaining expression
+    """
+    parts = query_expr.split(LOOKUP_SEP)
+    opts = model._meta
+    fields = []
+
+    # walk relationships
+    for i, name in enumerate(parts):
+        try:
+            field = opts.get_field(name)
+        except FieldDoesNotExist:
+            return fields, LOOKUP_SEP.join(parts[i:])
+
+        fields.append(field)
+        if isinstance(field, RelatedField):
+            opts = field.remote_field.model._meta
+        elif isinstance(field, ForeignObjectRel):
+            opts = field.related_model._meta
+
+    return fields, "exact"
+
+
 def get_filtering_args_from_filterset(filterset_class, type):
     """ Inspect a FilterSet and produce the arguments to pass to
         a Graphene Field. These arguments will be available to
@@ -18,22 +46,15 @@ def get_filtering_args_from_filterset(filterset_class, type):
         if name in filterset_class.declared_filters:
             form_field = filter_field.field
         else:
-            try:
-                field_name, filter_type = name.rsplit("__", 1)
-            except ValueError:
-                field_name = name
-                filter_type = None
+            fields, lookup_expr = get_field_parts_with_expression(model, name)
+            assert fields, str((model, name, filterset_class))
+            model_field = fields[-1]
+            filter_type = lookup_expr
 
-            # If the filter type is `isnull` then use the filter provided by
-            # DjangoFilter (a BooleanFilter).
-            # Otherwise try and get a filter based on the actual model field
-            if filter_type != "isnull" and hasattr(model, field_name):
-                model_field = model._meta.get_field(field_name)
-
-                if hasattr(model_field, "formfield"):
-                    form_field = model_field.formfield(
-                        required=filter_field.extra.get("required", False)
-                    )
+            if filter_type != "isnull" and hasattr(model_field, "formfield"):
+                form_field = model_field.formfield(
+                    required=filter_field.extra.get("required", False)
+                )
 
         # Fallback to field defined on filter if we can't get it from the
         # model field