`from_json` doesn't seem to recognize generic attributes

[fhennecker]

I tried adapting one example from the doc to generic dataclasses.

The following example fails to parse the Minions as such.

from dataclasses import dataclass
from dataclasses_json import dataclass_json
from typing import TypeVar, Generic, List

T = TypeVar("T", str, int)


@dataclass_json
@dataclass(frozen=True)
class Minion(Generic[T]):
    name: T


@dataclass_json
@dataclass(frozen=True)
class Boss(Generic[T]):
    minions: List[Minion[T]]


boss = Boss([Minion("evil minion"), Minion("very evil minion")])

print(Boss.from_json(boss.to_json()))

This is the result, as you can see the minions are still dicts, not Minions

Boss(minion1={'name': 'evil minion'}, minion2={'name': 'very evil minion'})

Am I doing something wrong?

[fhennecker]

My current best workaround is to specify a decoder like this:

from dataclasses import dataclass, field
from dataclasses_json import dataclass_json, config

@dataclass_json
@dataclass(frozen=True)
class Boss(Generic[T]):
    minion: Minion[T] = field(metadata=config(decoder=Minion.from_dict))

[george-zubrienko]

Target of #442