DocumentSettings ignore extra fields Pydantic Validation

[dynalz]

When setting the default pydantic Config to forbid extra fields:

from pydantic import config, Extra
config.BaseConfig.extra = Extra.forbid

Beanie throws errors at document initialization due to the following:

ValidationError: 4 validation errors for DocumentSettings __dict__
  extra fields not permitted (type=value_error.extra)
__doc__
  extra fields not permitted (type=value_error.extra)
__module__
  extra fields not permitted (type=value_error.extra)
__weakref__
  extra fields not permitted (type=value_error.extra)

The proposed commit fixes the issue.
Not sure if ideal, or if there is any caveats with this solution

[roman-right]

Hi!

Sorry, I didn't get the use-case. Could you please explain it a bit?

[dynalz]

So in our dev environment, we use Pydantic with more enforced rules and Dataclasses on production (for performance issues)

Thus in our dev environment we force all typing and all issues that mimic dataclasses, so that when it goes into production we have no issues. (This is for our service dataclasses, not related to beanie)

This is our use case:

if SETTINGS.is_production() or TYPE_CHECKING:
    # production environment
    from dataclasses import dataclass
else:
    # dev environment
    # pydantic enforced configuration
    from pydantic.dataclasses import dataclass
    ...
    config.BaseConfig.extra = Extra.forbid
    config.BaseConfig.validate_all = True
    config.BaseConfig.validate_assignment = True
    config.BaseConfig.arbitrary_types_allowed = True
    ...

The config.BaseConfig.extra = Extra.forbid is so that it avoids anyone passing extra variables that are not meant for the dataclass as shown below:

from dataclasses import dataclass

@dataclass
class Person:
    name: str

Person(**{"name": "John", "foo": "bear"}) # throws error on dataclasses module but not on pydantic module

this throws error as @dataclass comes from dataclasses module, but not if comes from pydantic.dataclasses module. Thus why the line config.BaseConfig.extra = Extra.forbid when using pydantic to mimic the dataclasses module behaviour, throwing exception on dataclasses initialization when passing arguments which are not valid for that dataclass.

However after we do the config.BaseConfig.extra = Extra.forbid (replacing the default Extra.ignore on pydantic) beanie throws at initializing DocumentSettings since it receives extra fields not defined on its model such as __dict__, __doc__, __module__ and __weakref__

Effectively with this commit the behaviour should remain the same for beanie since the Pydantic Config extra = Extra.ignore is already the default and currently being used on DocumentSettings

Let me know if this made sense

[dynalz]

Let me know if some more clarification is needed

[roman-right]

Hi. Sorry for the late reply. I had a lot of work with Pydantic V2 compatibility. If you still need this feature, could you please resolve the conflict and adapt this to work with Pydantic V2 (and still work with V1)?

[roman-right]

It looks like this PR is not in work more. If no, feel free to open a new one.