Bug: Bug when generating Json fields in Pydantic model

[Leobouloc]

Description

It seems like generating Json fields in Pydantic (1.10) creates a bug. Trying the factory_use_construct=True does not help as it provides a JsonWrapperValue object which is not a valid Json.

URL to code causing the issue

No response

MCVE

from typing import Dict
from pydantic import Json, BaseModel

from polyfactory.factories.pydantic_factory import ModelFactory

class MyModel(BaseModel):
    myfield: Json[Dict[str,str]]

class MyModelFactory(ModelFactory[MyModel]):
    __model__ = MyModel

print(type(MyModelFactory.build(factory_use_construct=True).myfield))
# >> HAS INVALID TYPE
# <class '.JsonWrapperValue'>

MyModelFactory.build()
# >> RAISES EXCEPTION:
# E   pydantic.error_wrappers.ValidationError: 1 validation error for MyModel
# E   myfield
# E     JSON object must be str, bytes or bytearray (type=type_error.json)

Release Version

2.12.0

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[guacs]

Aah Json fields aren't supported for v1. I don't exactly remember why that decision was made, even though I'm the one who did it 😅

I'll see if it's possible to add support for it. As a workaround until it's fixed, you can override the build method to convert the value into a JSON string before the kwargs are passed to the constructor of the model.

[Leobouloc]

Thank you for your answer! I will look into the solution you propose. Do you have any idea when support could be added (if it is actually possible) ?

[guacs]

@Leobouloc I think it's going to be at least January mid or so before I'll get a chance to work on it. However, if someone else is willing to raise a PR for this, I'd be happy to review it!