Use defaults values from BaseModel in ModelFactory

[ShtykovaAA]

Summary

I think it would be great if ModelFactory can use defaults values from BaseModel

Basic Example

For example I have class AppSettings, where I set app_title as APP_TITLE by default

from pydantic import BaseModel, Field
from polyfactory.factories.pydantic_factory import ModelFactory

APP_TITLE = 'title'


class AppSettings(BaseModel):
    app_title: str = Field(APP_TITLE)

    some_another_field: int

And now I can specify app_title as APP_TITLE in ModelFactory if only I set it model

class AppSettingsFactory(ModelFactory):
    __model__ = AppSettings
    app_title = APP_TITLE

So I think it would be great to have an extra param for using defaults in ModelFactory. Maybe something like this

class AppSettingsFactory(ModelFactory):
    __model__ = AppSettings
    __use_defaults__ = True

Drawbacks and Impact

No response

Unresolved questions

No response

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[guacs]

@ShtykovaAA yeah this is definitely possible. The default values are parsed and stored when parsing the model already so this shouldn't be a difficult addition.

Just to clarify, when setting __use_defaults__ = True then the default value will be used for all the fields that have a default value or default factory. This is the expected behavior, correct?

[ShtykovaAA]

@guacs correct!

[guacs]

@adhtruong am I right in thinking we don't have to worry about the defaults when it comes to the SQLAFactory since that would be handled by sqlalchemy itself?

[adhtruong]

@guacs SQLAlchemy has a couple forms on default

1. https://docs.sqlalchemy.org/en/20/orm/mapping_api.html#sqlalchemy.orm.mapped_column.params.default an in memory default
2. Or an insert default

In both cases, omitting the parameter itself should trigger using the default. Case 1 could be handled the same as above implementation but 2 is a bit more complex as may rely on a db (e.g. primary key with sequence).