Test helpers

[samueljsb]

I sometimes want to assert that a particular integrity error was raised during a test. At the moment I can do:

import pytest
from django.db.utils import IntegrityError

def test_():
    with pytest.raises(IntegrityError):
        ...

But, if I want to know which integrity error I'm catching, I need to either do some regexp matching on its message, or dig into the internals like this library does.

I'd love to be able to do:

from django_integrity import conversion, testing

def test_():
    with testing.raises(
        conversion.Unique(model=User, fields=("email",))
    ):
        ...

---

alternatives

I could also wrap the existing conversion code:

from django_integrity import conversion

def test_():
    class _MyIntegrityError(Exception):
        pass

   with (
        pytest.raises(_MyIntegrityError),
        conversion.refine_integrity_error(
            [(conversion.Unique(model=User, fields=("email",)), _MyIntegrityError)]
        ),
    ):
        ...

But that's a bit awkward. A helper for it would be so much easier to use.