Merge pull request #21 from mahdihaghverdi/issue#18

fix issue #18

Author: seyed-dev

aggify/aggify.py

@@ -209,6 +209,7 @@ def __to_aggregate(self, query: dict[str, Any]) -> None:
                     ]
                 )
 
+    @last_out_stage_check
     def __getitem__(self, index: slice | int) -> "Aggify":
         """
         # TODO: missing docs

tests/test_aggify.py

@@ -358,11 +358,12 @@ def test_out_with_project_stage_error(self):
     @pytest.mark.parametrize(
         ("method", "args"),
         (
-                ("group", ("_id",)),
-                ("order_by", ("field",)),
-                ("raw", ({"$query": "query"},)),
-                ("add_fields", ({"$field": "value"},)),
-                ("filter", (Q(age=20),)),
+            ("group", ("_id",)),
+            ("order_by", ("field",)),
+            ("raw", ({"$query": "query"},)),
+            ("add_fields", ({"$field": "value"},)),
+            ("filter", (Q(age=20),)),
+            ("__getitem__", (slice(2, 10),))
         ),
     )
     def test_out_stage_error(self, method, args):