[BUG] Custom types like bson.Binary require __get_pydantic_core_schema__

[Luc1412]

Describe the bug
With pydantic 2.0 custom types like in my case bson.Binary cause issues. You either need to create a config with arbitrary_types_allowed = True or implement __get_pydantic_core_schema__

This is the error:

pydantic.errors.PydanticSchemaGenerationError: Unable to generate pydantic-core schema for <class 'bson.binary.Binary'>. Set \`arbitrary_types_allowed=True\` in the model_config to ignore this error or implement \`__get_pydantic_core_schema__\` on your type to fully support it.

If you got this error by calling handler(<some type>) within `__get_pydantic_core_schema__` then you likely need to call `handler.generate_schema(<some type>)` since we do not call `__get_pydantic_core_schema__` on `<some type>` otherwise to avoid infinite recursion.

For further information visit https://errors.pydantic.dev/2.1.1/u/schema-for-unknown-type

To Reproduce

class ExampleEntry(BaseModel):
    example: bson.Binary

Expected behavior
It works without any issue

Additional context
Discord: https://ptb.discord.com/channels/822196934973456394/822196935435747332/1138966773044101190

[roman-right]

Hi! Thank you for the catch. I'll check it out in the next bug-fixing session this or next week

[roman-right]

The thing is Pydantic v2 needs some additional effort to support custom types.
I've added a type inherited from bson.Binary to Beanie. You can use it this way:

from beanie import BsonBinary

class Sample(Document):
    binary_field: BsonBinary

Please let me know if you have any issues with it.
It is implemented in the PR: #669

[Luc1412]

There is an issue with the subtype. When using BsonBinary the subtype seems to be always 0. Before it was properly set, in my case 6.

[github-actions]

This issue is stale because it has been open 30 days with no activity.

[Luc1412]

@roman-right Any news regarding this?

[gsakkis]

Should have been fixed by #739

[Luc1412]

Thanks, your PR solved this issue.