Allow to keep the types as they were and just add a default value

[KrilleGH]

It's still possible to omit all unchanged fields in PATCH requests, but for fields that are given Pydantic will reject data that specifies an explicit null for fields that aren't optional in the full model.

This is useful when using the package with SQLModel. Without this feature the client could try to assign a NULL value to a column with a NOT NULL constraint, which would raise an IntegrityError.

[ddanier]

I understand the issue here, but I don't think this will work for all cases. Pydantic might have issues with the default value not matching the type definition.

Could you add some tests to ensure this all works? ...including this None does not match the type definition thing?

[KrilleGH]

Hey @ddanier,

here are some tests for the feature. Is that how you imagined?

It seems Pydantic V1 handles default values differently so _field_get_default() doesn't return the expected values. Do you happen to know how to fix that? Otherwise we could also skip the test for Pydantic V1, it doesn't seem so important.

What is more important is that test_validate_fail doesn't raise on Pydantic V1, is this something where this version behaved differently?

Is there special need to remain compatible with Pydantic V1? Otherwise this feature could just be supported on V2.

Cheers
Christian