Dependency between fields in model using Factoryboy

Question

I have a Django Model that I would like to test using Factoryboy.

The issue here is that the fields depend on each other.

class SearchPreferences(models.Model):
    min_age = models.PositiveSmallIntegerField(null=True)
    max_age = models.PositiveSmallIntegerField(null=True)

In this case, max_age cannot be smaller then min_age.

class SearchPreferencesFactory(DjangoModelFactory):
    min_age = FuzzyInteger(30, 90)
    max_age = FuzzyInteger(SelfAttribute('min_age'), 100)

This is what I have tried to do, which should give me a value for max_age between min_age and 100, but what happens is a TypeError:

TypeError: unsupported operand type(s) for +: 'SelfAttribute' and 'int'

This makes sense to me, but I can't really figure out how to get this to work?

Could someone explain what would be the best approach here?

Answer 1

You could use a LazyAttribute on your max_age, ie:

class SearchPreferencesFactory(DjangoModelFactory):
    min_age = FuzzyInteger(30, 90)
    max_age = LazyAttribute(lambda x: FuzzyInteger(x.min_age, 100).fuzz())