Have a way on a Factory to configure whether a field is generated for that overrides blank/null

[James Westby]

As sometimes people want this but don't want to change blank/null.

[Michael Nelson (michael.nelson)]

I'm not sure if this is the same thing, but for models with nullable foreign keys, I find my self adding custom factories like this to the model:

{{{
class Transaction(models.Model):
    ...
    category = models.ForeignKey('categories.Category', null=True, blank=True)

    class Factory:
        @staticmethod
        def get_category(field, factory):
            return factory.prepare_one(Category)
}}}

This is because, mostly if I have a nullable field, it's usually because the data is not yet available, but it's always intended to be filled. There fore the majority of my tests want every Transaction with a category, and overriding this for the few tests that don't is already handled out-of-the-box by django-factor with `factory.make_one(Transaction, category=None)`

This is not the case the other way around - if the default is to create Transactions with a null category, then all those tests requiring a category need quite a bit more code: `factory.make_one(Transaction, category=factory.make_one(Category))'.

I'm not sure yet if it's fair to say that it should be the default to populate nullable FKs - but it seems that a value of null on a nullable FK is the exception, rather than the rule - not sure.