JsonConverter.structure cannot handle Annotated union type. #418
Description
- cattrs version: 23.1.2
- Python version: 3.11.4
- Operating System: Mac OS 13.4.1 (c)
Description
cattrs fails when attempting to structure data using a class with an Annotated union type.
What I Did
The code:
from typing import Annotated
import attrs
from cattrs.preconf.json import make_converter
conv = make_converter()
@attrs.define
class GoodModel:
name: Annotated[str, 'required']
@attrs.define
class BadModel:
name: Annotated[str | None, 'required']
data = {'name': 'test'}
print('Loading data using GoodModel.')
conv.structure(data, GoodModel)
print('Loading data using GoodModel succeeded.')
print('Loading data using BadModel.')
conv.structure(data, BadModel)
and the output:
Loading data using GoodModel.
Loading data using GoodModel succeeded.
Loading data using BadModel.
+ Exception Group Traceback (most recent call last):
| File "/Users/charles/Documents/annotated_test.py", line 20, in <module>
| conv.structure(data, BadModel)
| File "/Users/charles/Documents/ccWrangler/git/ccwrangler-api/.venv/3.11.4/lib/python3.11/site-packages/cattrs/converters.py", line 334, in structure
| return self._structure_func.dispatch(cl)(obj, cl)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "<cattrs generated structure __main__.BadModel>", line 9, in structure_BadModel
| cattrs.errors.ClassValidationError: While structuring BadModel (1 sub-exception)
+-+---------------- 1 ----------------
| Traceback (most recent call last):
| File "<cattrs generated structure __main__.BadModel>", line 5, in structure_BadModel
| File "/Users/charles/Documents/ccWrangler/git/ccwrangler-api/.venv/3.11.4/lib/python3.11/site-packages/cattrs/converters.py", line 646, in _structure_optional
| other = union_params[0] if union_params[1] is NoneType else union_params[1]
| ~~~~~~~~~~~~^^^
| IndexError: tuple index out of range
| Structuring class BadModel @ attribute name