pytest-factoryboy 1.0.2

Factory Boy support for pytest.

factory_boy integration the pytest runner

pytest-factoryboy makes it easy to combine factory approach to the test setup with the dependency injection, heart of the pytest fixtures.

Install pytest-factoryboy

pip install pytest-factoryboy

Concept

Library exports a function to register factories as fixtures. Fixtures are contributed to the same module where register function is called.

Factory Fixture

Factory fixtures allow using factories without importing them. Name convention is lowercase-underscore class name.

import factory

class AuthorFactory(Factory):

    class Meta:
        model = Author


register(Author)


def test_factory_fixture(author_factory):
    author = author_fixture(name="Charles Dickens")
    assert author.name == "Charles Dickens"

Model Fixture

Model fixture implements an instance of a model created by the factory. Name convention is lowercase-underscore class name.

import factory
from pytest_factoryboy import register

@register
class AuthorFactory(Factory):

    class Meta:
        model = Author

    name = "Charles Dickens"


def test_model_fixture(author):
    assert author.name == "Charles Dickens"

Model fixtures can be registered with specific names. For example if you address instances of some collection by the name like “first”, “second” or of another parent as “other”:

register(BookFactory)  # book
register(BookFactory, name="second_book")  # second_book

register(AuthorFactory) # author
register(AuthorFactory, name="second_author") # second_author

register(BookFactory, name="other_book")  # other_book, book of another author

@pytest.fixture
def other_book__author(second_author):
    """Make the relation of the second_book to another (second) author."""
    return second_author

Attributes are Fixtures

There are fixtures created for factory attributes. Attribute names are prefixed with the model fixture name and double underscore (similar to factory boy convention).

@pytest.mark.parametrized("author__name", ["Bill Gates"])
def test_model_fixture(author):
    assert author.name == "Bill Gates"

SubFactory

Sub-factory attribute points to the model fixture of the sub-factory. Attributes of sub-factories are injected as dependencies to the model fixture and can be overridden in the parametrization.

Related Factory

Related factory attribute points to the model fixture of the related factory. Attributes of related factories are injected as dependencies to the model fixture and can be overridden in the parametrization.

post-generation

Post-generation attribute fixture implements only the extracted value for the post generation function.

Integration

An example of factory_boy and pytest integration.

factories/__init__.py:

import factory
from faker import Factory as FakerFactory

faker = FakerFactory.create()


class AuthorFactory(factory.django.DjangoModelFactory):

    """Author factory."""

    name = factory.LazyAttribute(lambda x: faker.name())

    class Meta:
        model = 'app.Author'


class BookFactory(factory.django.DjangoModelFactory):

    """Book factory."""

    title = factory.LazyAttribute(lambda x: faker.sentence(nb_words=4))

    class Meta:
        model = 'app.Book'

    author = factory.SubFactory(AuthorFactory)

tests/conftest.py:

from pytest_factoryboy import register

from factories import AuthorFactory, BookFactory

register(AuthorFactory)
register(BookFactory)

tests/test_models.py:

from app.models import Book
from factories import BookFactory

def test_book_factory(book_factory):
    """Factories become fixtures automatically."""
    assert isinstance(book_factory, BookFactory)

def test_book(book):
    """Instances become fixtures automatically."""
    assert isinstance(book, Book)

@pytest.mark.parametrize("book__title", ["PyTest for Dummies"])
@pytest.mark.parametrize("author__name", ["Bill Gates"])
def test_parametrized(book):
    """You can set any factory attribute as a fixture using naming convention."""
    assert book.name == "PyTest for Dummies"
    assert book.author.name == "Bill Gates"

License

This software is licensed under the MIT license.

© 2015 Oleg Pidsadnyi, Anatoly Bubenkov and others

Authors

Oleg Pidsadnyi

original idea and implementation

These people have contributed to pytest-factoryboy, in alphabetical order:

• Anatoly Bubenkov

Changelog

1.0.2

• refactoring of the fixture function compilation (olegpidsadnyi)

• related factory fix (olegpidsadnyi)

• post_generation fixture dependency fixed (olegpidsadnyi)

• model fixture registration with specific name (olegpidsadnyi)

• README updated (olegpidsadnyi)

1.0.1

• use inflection package to convert camel case to underscore (bubenkoff)

1.0.0

• initial release (olegpidsadnyi)