[bug] "'coroutine' object has no attribute 'to_dict'." in trace_async_validator

[SwaY2000]

Describe the bug
When using the ExampleAsyncValidator with AsyncGuard in versions 0.5.4 through 0.6.0, an error occurs:
'coroutine' object has no attribute 'to_dict'.

The issue appears in the trace_async_validator method of the framework during the call:

resp = await fn(*args, **kwargs)

If resp is awaited again (resp = await resp), the error disappears, and everything works as expected. In versions up to 0.5.3 (inclusive) there was no such problem.

To Reproduce
Steps to reproduce the behavior:

RAIL Spec
Use the following custom validator:

import asyncio

from guardrails import AsyncGuard, register_validator
from guardrails.validators import Validator, ValidationResult, PassResult, FailResult


@register_validator(name="example-async-validator", data_type="string")
class ExampleAsyncValidator(Validator):
    async def validate(self, value: str, metadata: dict) -> ValidationResult:
        # Simulate async logic
        if "invalid" in value:
            return FailResult(error_message="Validation failed.")
        return PassResult(metadata={"validated": True})

async def main():
    async_guard = AsyncGuard()
    async_guard.use(ExampleAsyncValidator)

    # Validate a value
    result = await async_guard.validate("test invalid value")

asyncio.run(main())

Expected behavior
The validator should work as expected without needing to explicitly double-await the result (await resp).

Library version:
0.5.4 to 0.6.0

Additional context
The issue seems to originate from the handling of coroutines within the trace_async_validator method. Previously, the framework might have handled the asynchronous results differently, causing this regression in the later versions.

Temporary workaround:
Explicitly double-await the result in the trace_async_validator:

resp = await fn(*args, **kwargs)
resp = await resp

[SwaY2000]

@zsimjee Hello! Please tell me, is there anything known about this problem? Is this a problem on the framework side? If yes, please tell me, in what time frame can I expect a fix?

[CalebCourier]

Hi @SwaY2000, Sorry for the delayed response. The issue here is that you are setting the validate method to an async function which does not match the parent Validator class' specification; it must by synchronous. If your validation logic is truly asynchronous, you should override async_validate instead.

Note that this would restrict ExampleAsyncValidator to only working with AsyncGuards unless you used something like nest-asyncio to also provide a synchronous validate implementation.