Examples

Here are some real-world examples of using FactoryBoy.

Objects

First, let’s define a couple of objects:

class Account(object):
    def __init__(self, username, email):
        self.username = username
        self.email = email

    def __str__(self):
        return '%s (%s)' % (self.username, self.email)


class Profile(object):

    GENDER_MALE = 'm'
    GENDER_FEMALE = 'f'
    GENDER_UNKNOWN = 'u'  # If the user refused to give it

    def __init__(self, account, gender, firstname, lastname, planet='Earth'):
        self.account = account
        self.gender = gender
        self.firstname = firstname
        self.lastname = lastname
        self.planet = planet

    def __unicode__(self):
        return u'%s %s (%s)' % (
            unicode(self.firstname),
            unicode(self.lastname),
            unicode(self.account.accountname),
        )

Factories

And now, we’ll define the related factories:

import factory
import random

from . import objects


class AccountFactory(factory.Factory):
    FACTORY_FOR = objects.Account

    username = factory.Sequence(lambda n: 'john%s' % n)
    email = factory.LazyAttribute(lambda o: '%s@example.org' % o.username)


class ProfileFactory(factory.Factory):
    FACTORY_FOR = objects.Profile

    account = factory.SubFactory(AccountFactory)
    gender = random.choice([objects.Profile.GENDER_MALE, objects.Profile.GENDER_FEMALE])
    firstname = u'John'
    lastname = u'Doe'

We have now defined basic factories for our Account and Profile classes.

If we commonly use a specific variant of our objects, we can refine a factory accordingly:

class FemaleProfileFactory(ProfileFactory):
    gender = objects.Profile.GENDER_FEMALE
    firstname = u'Jane'
    user__username = factory.Sequence(lambda n: 'jane%s' % n)

Using the factories

We can now use our factories, for tests:

import unittest

from . import business_logic
from . import factories
from . import objects


class MyTestCase(unittest.TestCase):

    def test_send_mail(self):
        account = factories.AccountFactory()
        email = business_logic.prepare_email(account, subject='Foo', text='Bar')

        self.assertEqual(email.to, account.email)

    def test_get_profile_stats(self):
        profiles = []

        for _ in xrange(4):
            profiles.append(factories.ProfileFactory())
        for _ in xrange(2):
            profiles.append(factories.FemaleProfileFactory())
        for _ in xrange(2):
            profiles.append(factories.ProfileFactory(planet='Tatooine'))

        stats = business_logic.profile_stats(profiles)
        self.assertEqual({'Earth': 6, 'Mars': 2}, stats.planets)
        self.assertLess(stats.genders[objects.Profile.GENDER_FEMALE], 2)

Or for fixtures:

from . import factories

def make_objects():
    for _ in xrange(50):
        factories.ProfileFactory()

    # Let's create a few, known objects.
    factories.ProfileFactory(
        gender=objects.Profile.GENDER_MALE,
        firstname='Luke',
        lastname='Skywalker',
        planet='Tatooine',
    )

    factories.ProfileFactory(
        gender=objects.Profile.GENDER_FEMALE,
        firstname='Leia',
        lastname='Organa',
        planet='Alderaan',
    )