Pytest fixtures

Polyfactory support registering factories as pytest fixtures using the register_fixture decorator:

Using the register_fixture_decorator field.

from dataclasses import dataclass
from datetime import date, datetime
from typing import Optional, Union
from uuid import UUID

from polyfactory.factories import DataclassFactory
from polyfactory.pytest_plugin import register_fixture


@dataclass
class Person:
    id: UUID
    name: str
    hobbies: Optional[list[str]]
    nicks: list[str]
    age: Union[float, int]
    birthday: Union[datetime, date]


@register_fixture
class PersonFactory(DataclassFactory[Person]): ...


def test_person_factory(person_factory: PersonFactory) -> None:
    person_instance = person_factory.build()
    assert isinstance(person_instance, Person)

    # The factory class itself can still be used
    another_person_instance = PersonFactory.build()
    assert isinstance(another_person_instance, Person)

The fixture can be registered separately from the declaration of the class. This is useful when a different pytest fixture location to where the factory is defined.

Using the register_fixture_decorator field separately.

from dataclasses import dataclass
from datetime import date, datetime
from typing import Optional, Union
from uuid import UUID

from polyfactory.factories import DataclassFactory
from polyfactory.pytest_plugin import register_fixture


@dataclass
class Person:
    id: UUID
    name: str
    hobbies: Optional[list[str]]
    nicks: list[str]
    age: Union[float, int]
    birthday: Union[datetime, date]


class PersonFactory(DataclassFactory[Person]): ...


register_fixture(PersonFactory)


def test_person_factory(person_factory: PersonFactory) -> None:
    person_instance = person_factory.build()
    assert isinstance(person_instance, Person)

You can also control the name of the fixture using the optional name kwarg:

Aliasing a factory fixture using the name kwarg.

from dataclasses import dataclass
from datetime import date, datetime
from typing import Optional, Union
from uuid import UUID

from polyfactory.factories import DataclassFactory
from polyfactory.pytest_plugin import register_fixture


@dataclass
class Person:
    id: UUID
    name: str
    hobbies: Optional[list[str]]
    nicks: list[str]
    age: Union[float, int]
    birthday: Union[datetime, date]


@register_fixture(name="aliased_person_factory")
class PersonFactory(DataclassFactory[Person]): ...


def test_person_factory(aliased_person_factory: PersonFactory) -> None:
    person_instance = aliased_person_factory.build()
    assert isinstance(person_instance, Person)