Transformer not used with trait and value override

[chriswyatt]

Description

When defining a transformer within a trait, then overriding that value, the transform is not applied.

To Reproduce

See code example below

Model / Factory code

import factory


class FooFactory(factory.StubFactory):
    foo = factory.Transformer(123, transform=hex)

    class Params:
        string = factory.Trait(foo=factory.Transformer(234, transform=str))


if __name__ == '__main__':
    print(FooFactory(foo=345).__dict__)  # {'foo': 345}

[rodrigobnogueira]

Hello @chriswyatt ,

I was trying to understand what happens in the factory boy related to this bug:

class FooFactory(factory.StubFactory):
    foo = factory.Transformer(123, transform=hex)
    class Params:
        string = factory.Trait(foo=factory.Transformer(234, transform=str))

# What factory_boy creates internally for field 'foo':
foo = Maybe(
    decider=SelfAttribute('string'),  # Check if trait is active
    yes_declaration=Transformer(234, transform=str),  # Trait's transformer
    no_declaration=Transformer(123, transform=hex),   # Original transformer
)

Transformer has CAPTURE_OVERRIDES = True: Overrides are passed to the Transformer
Maybe has CAPTURE_OVERRIDES = False (inherited from BaseDeclaration): Overrides REPLACE the Maybe entirely

when a Trait wraps a field, the Maybe declaration doesn't capture overrides. it gets replaced by the raw value.

[rodrigobnogueira]

Simple fix:

Just added CAPTURE_OVERRIDES propagation from no_declaration in Maybe.init

self.CAPTURE_OVERRIDES = getattr(no_declaration, 'CAPTURE_OVERRIDES', False)