change error message when a lookup does not exists in EMF

Author: WaVEV

django_mongodb_backend/fields/embedded_model.py

@@ -150,8 +150,8 @@ def get_transform(self, name):
         else:
             if self.ref_field.get_transform(name) is None:
                 raise FieldDoesNotExist(
-                    f"{self.ref_field.model._meta.object_name}.{self.ref_field.name}"
-                    f" has no field named '{name}'"
+                    f"Unsupported lookup '{name}' for "
+                    f"{self.ref_field.__class__.__name__} '{self.ref_field.name}'"
                 )
             result = KeyTransformFactory(name, self.ref_field)
         return result

tests/model_fields_/test_embedded_model.py

@@ -105,7 +105,7 @@ def test_nested(self):
         self.assertCountEqual(Book.objects.filter(author__address__city="NYC"), [obj])
 
     def test_nested_not_exists(self):
-        msg = "Address.city has no field named 'president'"
+        msg = "Unsupported lookup 'president' for CharField 'city'"
         with self.assertRaisesMessage(FieldDoesNotExist, msg):
             Book.objects.filter(author__address__city__president="NYC")