GenConverter's unstructure RecursionError with class with forwardRef #159
Description
- cattrs version: 1.4.0
- Python version: 3.9.1
- Operating System: Mac OS Big Sur
Description
After something that worked with cattrs 1.3.0, raises a RecursionError with 1.4.0.
With an attrs class defined with forward referencing annotations, GenConverter's unstructure exceeds it's recursion depth.
I expected unstructure to turn an instance of a class into a dict.
What I Did
from __future__ import annotations
from typing import Optional, List
import attr
from cattr import GenConverter
unstructure = GenConverter().unstructure
@attr.s
class Node(object):
name: str = attr.ib()
nodes: List[Node] = attr.ib(default=attr.Factory(list))
n = Node("Bob", nodes=[Node("Jim")])
>>> d = unstructure(n)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/converters.py", line 153, in unstructure
return self._unstructure_func.dispatch(
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 47, in _dispatch
return self._function_dispatch.dispatch(cl)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 121, in dispatch
return handler(typ)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/converters.py", line 645, in gen_unstructure_attrs_fromdict
h = make_dict_unstructure_fn(
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/gen.py", line 46, in make_dict_unstructure_fn
handler = converter._unstructure_func.dispatch(a.type)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 47, in _dispatch
return self._function_dispatch.dispatch(cl)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 121, in dispatch
return handler(typ)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/converters.py", line 675, in gen_unstructure_iterable
h = make_iterable_unstructure_fn(
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/gen.py", line 214, in make_iterable_unstructure_fn
handler = converter._unstructure_func.dispatch(type_arg)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 47, in _dispatch
return self._function_dispatch.dispatch(cl)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/dispatch.py", line 121, in dispatch
return handler(typ)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/converters.py", line 645, in gen_unstructure_attrs_fromdict
h = make_dict_unstructure_fn(
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/gen.py", line 32, in make_dict_unstructure_fn
attrs = adapted_fields(cl) # type: ignore
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/cattr/_compat.py", line 80, in adapted_fields
return attrs_fields(type)
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/attr/_make.py", line 1763, in fields
if not isclass(cls):
File "/Users/john/.pyenv/versions/br3/lib/python3.9/site-packages/attr/_compat.py", line 118, in isclass
return isinstance(klass, type)
RecursionError: maximum recursion depth exceeded while calling a Python object