fix: Do not try to call an ordering object's order method if it is …

…not a decorated method (#584)

strawberry_django/ordering.py

@@ -108,8 +108,10 @@ def process_order(
     sequence = sequence or {}
     args = []
 
-    if not skip_object_order_method and (order_method := getattr(order, "order", None)):
-        assert isinstance(order_method, FilterOrderFieldResolver)
+    if not skip_object_order_method and isinstance(
+        order_method := getattr(order, "order", None),
+        FilterOrderFieldResolver,
+    ):
         return order_method(
             order, info, queryset=queryset, prefix=prefix, sequence=sequence
         )

tests/test_ordering.py

@@ -1,9 +1,11 @@
 # ruff: noqa: TRY002, B904, BLE001, F811, PT012
 from typing import Any, List, Optional, cast
+from unittest import mock
 
 import pytest
 import strawberry
 from django.db.models import Case, Count, Value, When
+from pytest_mock import MockFixture
 from strawberry import auto
 from strawberry.annotation import StrawberryAnnotation
 from strawberry.exceptions import MissingArgumentsAnnotationsError
@@ -331,6 +333,33 @@ def custom_order(self, root, info, prefix, value: auto, sequence, queryset):
         process_order(_order, _info, _queryset, prefix="ROOT", sequence=_sequence)
 
 
+def test_order_method_not_called_when_not_decorated(mocker: MockFixture):
+    @strawberry_django.ordering.order(models.Fruit)
+    class Order:
+        def order(self, root, info, prefix, value: auto, sequence, queryset):
+            pytest.fail("Should not have been called")
+
+    mock_order_method = mocker.spy(Order, "order")
+
+    process_order(
+        cast(WithStrawberryObjectDefinition, Order()), mock.Mock(), mock.Mock()
+    )
+
+    mock_order_method.assert_not_called()
+
+
+def test_order_field_not_called(mocker: MockFixture):
+    @strawberry_django.ordering.order(models.Fruit)
+    class Order:
+        order: Ordering = Ordering.ASC
+
+    # Calling this and no error being raised is the test, as the wrong behavior would
+    # be for the field to be called like a method
+    process_order(
+        cast(WithStrawberryObjectDefinition, Order()), mock.Mock(), mock.Mock()
+    )
+
+
 def test_order_object_method():
     @strawberry_django.ordering.order(models.Fruit)
     class Order: