Update tests

Author: ArpitSachan

tests/queryset/test_queryset.py

@@ -2600,20 +2600,33 @@ def test_order_by(self):
         assert ages == [40, 20, 30]
 
     def test_last(self):
-        """Ensure the retieval of the latest object from the QuerySet."""
+        """Ensure the retrieval of the latest object from the QuerySet based on the specified ordering."""
         person1 = self.Person(name="User B", age=40).save()
         person2 = self.Person(name="User A", age=20).save()
         person3 = self.Person(name="User C", age=30).save()
 
-        assert self.Person.objects.last() == person3
+        assert self.Person.objects.order_by('age').last() == person1
+        assert self.Person.objects.order_by('-age').last() == person2
 
         person2.age = 31
         person2.save()
-        assert self.Person.objects.last() == person3
+        assert self.Person.objects.order_by('-age').last() == person3
+        assert self.Person.objects.order_by('age').last() == person1
 
         person1.age = 41
         person1.save()
-        assert self.Person.objects.last() == person3
+        assert self.Person.objects.order_by('age').last() == person1
+
+        assert self.Person.objects.order_by('name').last() == person3
+
+        assert self.Person.objects.filter(age__lt=40).order_by('age').last() == person2
+        assert self.Person.objects.filter(age__gt=50).order_by('age').last() is None 
+
+        with pytest.raises(OperationError):
+            self.Person.objects.last()
+
+        person4 = self.Person(name="User D", age=30).save()
+        assert self.Person.objects.order_by('-age').last() == person4
 
     def test_order_by_optional(self):
         class BlogPost(Document):