diff --git a/src/finch/_qs.py b/src/finch/_qs.py
index e7aa3e13..274320ca 100644
--- a/src/finch/_qs.py
+++ b/src/finch/_qs.py
@@ -34,7 +34,7 @@ def __init__(
         self.nested_format = nested_format
 
     def parse(self, query: str) -> Mapping[str, object]:
-        # TODO
+        # Note: custom format syntax is not supported yet
         return parse_qs(query)
 
     def stringify(
@@ -89,9 +89,11 @@ def _stringify_item(
         if isinstance(value, (list, tuple)):
             array_format = opts.array_format
             if array_format == "comma":
-                # TODO: support list of objects?
                 return [
-                    (key, ",".join(self._primitive_value_to_str(item) for item in value if item is not None)),
+                    (
+                        key,
+                        ",".join(self._primitive_value_to_str(item) for item in value if item is not None),
+                    ),
                 ]
             elif array_format == "repeat":
                 items = []
diff --git a/tests/utils.py b/tests/utils.py
index 986f79fa..72c546d7 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -25,6 +25,10 @@ def assert_matches_model(model: type[BaseModelT], value: BaseModelT, *, path: li
 
 # Note: the `path` argument is only used to improve error messages when `--showlocals` is used
 def assert_matches_type(type_: Any, value: object, *, path: list[str]) -> None:
+    if type_ is None:
+        assert value is None
+        return
+
     origin = get_origin(type_) or type_
 
     if is_list_type(type_):