Add support for ForwardRef about mashumaro

[Fatal1ty]

@messense

I added initial support in the following PR. It's not complete yet but your example will work on python 3.10+.

• #145

On Python < 3.10 it gives NameError: name 'PreCheckConfig' is not defined. if you have any ideas on how to fix it, I'll be happy to listen. Otherwise I'll get to that later.

[Fatal1ty]

@messense

Good news! I managed to get it work on Python >= 3.8. If you have any other examples that don't work, I'd love to see them in a separate issue.

[messense]

BTW, build_json_schema(Config) also raises an exception

Traceback (most recent call last):
  File "/home/ubuntu/workspace/example/python/repro.py", line 19, in <module>
    print(build_json_schema(Config))
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/builder.py", line 45, in build_json_schema
    schema = get_schema(instance, context, with_dialect_uri=with_dialect_uri)
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 254, in get_schema
    schema = schema_creator(instance, ctx)
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 791, in on_collection
    return on_typed_dict(instance, ctx)
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 655, in on_typed_dict
    properties={
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 656, in <dictcomp>
    key: get_schema(instance.derive(type=annotations[key]), ctx)
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 254, in get_schema
    schema = schema_creator(instance, ctx)
  File "/home/ubuntu/workspace/example/.venv/lib/python3.10/site-packages/mashumaro/jsonschema/schema.py", line 709, in on_collection
    if not issubclass(instance.origin_type, typing.Collection):
  File "/usr/lib/python3.10/typing.py", line 1158, in __subclasscheck__
    return issubclass(cls, self.__origin__)
  File "/usr/lib/python3.10/abc.py", line 123, in __subclasscheck__
    return _abc_subclasscheck(cls, subclass)
TypeError: issubclass() arg 1 must be a class

[messense]

For comparison, it kinda works with pydantic 1.x. (I haven't tested 2.x):

from __future__ import annotations

from typing import TypedDict

from pydantic import create_model_from_typeddict


class PreCheckConfig(TypedDict):
    enable: bool


class Config(TypedDict):
    pre_check: PreCheckConfig


class ModelConfig:
    extra = "forbid"


ConfigModel = create_model_from_typeddict(Config, __config__=ModelConfig)
print(ConfigModel.parse_obj({"pre_check": {"enable": True}}))

outputs:

pre_check={'enable': True}

[Fatal1ty]

@messense

Yeah, right now ForwardRef is not supported but I'm definitely planning on adding it later on. In the meantime, you can use dataclasses instead of TypedDict:

from __future__ import annotations

from dataclasses import dataclass

from mashumaro.mixins.dict import DataClassDictMixin


@dataclass
class PreCheckConfig:
    enable: bool


@dataclass
class Config:
    pre_check: PreCheckConfig


@dataclass
class ConfigChecker(DataClassDictMixin):
    config: Config


ConfigChecker.from_dict({"config": {"pre_check": {"enable": True}}})

[messense]

Thanks, Python 3.10 support is good for me already.