Validation of required nested field is not consistent with previous version

[matejsp]

If you have a nested form on web or if you want to do validation it would be prefered to list the errors inside nested schema not just that nested item is missing. This way you can map the errors to a input form more preciesly.

In marhsmallow 2 you would get what is missing in required nested schema.

{'corpo_info': {'company_name': ['Missing data for required field.'], 'address': ['Missing data for required field.']}}

Now you get only:

{'corpo_info': ['Missing data for required field.']}

I prefer previous behaviour.

import marshmallow
from marshmallow import fields


class BeneficiaryCorpoInfo(marshmallow.Schema):
    company_name = fields.Str(load_only=True, allow_none=True, required=True)
    address = fields.Str(load_only=True, allow_none=True, required=True)


class BeneficiaryInfoDataSchema(marshmallow.Schema):

    corpo_info = fields.Nested(
        BeneficiaryCorpoInfo, required=True, load_only=True, allow_none=True
    )


try:
    if marshmallow.__version__.startswith('2.'):
        BeneficiaryInfoDataSchema(strict=True).load({})
    else:
        BeneficiaryInfoDataSchema().load({})
except marshmallow.ValidationError as e:
    print(e.messages)


BeneficiaryInfoDataSchema(strict=True).validate('')
# marhsmallow 2: {'corpo_info': {'company_name': ['Missing data for required field.'], 'address': ['Missing data for required field.']}}
# marshmallow 3: {'corpo_info': ['Missing data for required field.']}