chore(internal): fix bug with transform utility & key aliases (#7)

Author: stainless-bot

src/finch/_utils/_transform.py

@@ -115,7 +115,7 @@ def _maybe_transform_key(key: str, type_: type) -> str:
         return key
 
     # ignore the first argument as it is the actual type
-    annotations = get_args(type_)[1:]
+    annotations = get_args(annotated_type)[1:]
     for annotation in annotations:
         if isinstance(annotation, PropertyInfo) and annotation.alias is not None:
             return annotation.alias

tests/test_transform.py

@@ -177,3 +177,12 @@ def test_datetime_custom_format() -> None:
 
     result = transform(dt, Annotated[datetime, PropertyInfo(format="custom", format_template="%H")])
     assert result == "06"  # type: ignore[comparison-overlap]
+
+
+class DateDictWithRequiredAlias(TypedDict, total=False):
+    required_prop: Required[Annotated[date, PropertyInfo(format="iso8601", alias="prop")]]
+
+
+def test_datetime_with_alias() -> None:
+    assert transform({"required_prop": None}, DateDictWithRequiredAlias) == {"prop": None}  # type: ignore[comparison-overlap]
+    assert transform({"required_prop": date.fromisoformat("2023-02-23")}, DateDictWithRequiredAlias) == {"prop": "2023-02-23"}  # type: ignore[comparison-overlap]