Validator isn't called when Optional is set

[xunto]

Hi there. I think there is a bug. What I'm trying to do is to check if atleast one of two properties (login or dn) exists. But I if set them optional, validator is never called.

This example doesn't raise exception.

from typing import Optional

import pydantic
from pydantic import validator


class Authentication(pydantic.BaseModel):
    login: Optional[str]
    dn: Optional[str]

    password: str

    @validator('login', "dn", always=True, pre=True)
    def auth_specified(cls, value, values, **kwargs):
        if not value and not {"login", "dn"}.intersection(values.keys()):
            raise ValueError("No auth specified")
        return value


Authentication(password="asdd")

Checked on github master branch.

[samuelcolvin]

Thanks for reporting. I think this is the same problem I was trying to fix with #118.

The problem is, it took a big rewrite to fix. I'll have another go and see if I can find a way of fixing this without adversely effecting performance or current functionality.