ValueError when using `from __future__ import annotations` about argparse_dataclass

[mivade]

See lovasoa/marshmallow_dataclass#186 for a solution to a similar problem.

Personally I never do this import because it has caused problems in the past with other libraries but I would be willing to accept a PR that addresses this.

[ymd-h]

I encountered the same issue.
By patching argparse_dataclass.fields() based on @isbadawi's idea, I could solve the error.

from __future__ import annotations
from dataclasses import fields
import argparse_dataclass
from typing import get_type_hints

def _patch_fields(cls, *args, **kwargs):
    t = get_type_hints(cls)
    def _update(_f):
        _f.type = t[_f.name]
        return _f
    
    return tuple(_update(f) for f in fields(cls, *args, **kwargs))

argparse_dataclass.fields = _patch_fields


@argparse_dataclass.dataclass
class MyArgs:
    foo: int = 0
    bar: str = 'hello'
    baz: bool = False

def main():
    print(MyArgs.parse_args())

if __name__ == '__main__':
    main()

MyArgs(foo=0, bar='hello', baz=False)

[ymd-h]

@mivade
Thank you for your reply.

I sent PR (#51).