django-override-autonow

django-override-autonow is a testing tool for Django's project. django-override-autonow makes it easy to create model instance using DateField or DateTimeField with auto_now or auto_now_add options.

An example of django's model:

from django.db import models


class Order(models.Model):
    amount = models.IntegerField()
    status = models.CharField(max_length=100)
    created_time = models.DateTimeField(auto_now_add=True)
    updated_time = models.DateTimeField(auto_now=True)

To test this model:

from unittest import mock

from django.test import TestCase
from django.utils import timezone
from override_autonow import override_autonow

from .models import Order


class TestOrder(TestCase):

    @override_autonow
    def test_with_django_override_autonow(self):
        # We need a order with desired created_time and updated_time for test
        order = Order.objects.create(
            amount=200,
            status='PAID',
            created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
            updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
        )

        # test order

    def test_without_django_override_autonow(self):
        # Django's standard way is to mock timezone.now and save the model.

        # First, create object with mocking timezone.now and set desired value to created_time field
        with mock.patch('django.db.models.fields.timezone') as mock_timezone:
            mock_timezone.now.return_value = timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59)
            order = Order.objects.create(
                amount=200,
                status='PAID',
            )

        # Second, save object again with mocking timezone.now and set desired value to updated_time field
        with mock.patch('django.db.models.fields.timezone') as mock_timezone:
            mock_timezone.now.return_value = timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0)
            order.save()

        # test order

Features

• Support Django 2.2+ and Python 3.7+

• Compatible with major testing packages

  • pytest's class based test and function based test with pytest-django
  • factory-boy's model factory

• Choose suitable style for your situation

  • Method decorator
  • Class decorator
  • Context manager

• Flexible override target selection

  • Affects only specified field names and exclude specified field names
  • Affects only specified models and exclude specified field names
  • Affects only auto_now option or auto_now_add option
  • Affects only DateField or DateTimeField

Installation

Installing from PyPI:

pip install django-override-autonow

Use Cases

Test with Django's TestCase:

from django.test import TestCase

from override_autonow import override_autonow

from .models import Order


class TestOrder(TestCase):

    # as method decorator

    @override_autonow
    def test_with_method_decorator(self):
        order = Order.objects.create(
            amount=200,
            status='PAID',
            created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
            updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
        )

        # test order

    def test_with_context_manager(self):

        # as context manager

        with override_autonow():
            order_with_override = Order.objects.create(
                amount=200,
                status='PAID',
                created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
                updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
            )

        order_without_override = Order.objects.create(
            amount=200,
            status='PAID',
        )

        # test order


# as class decorator

@override_autonow
class TestWithClassDecorator(TestCase):
    def test_with_class_decorator(self):
        order = Order.objects.create(
            amount=200,
            status='PAID',
            created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
            updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
        )

        # test order

Test with pytest(pytest-django):

import pytest

from override_autonow import override_autonow

from .models import Order


@pytest.mark.django_db
class TestOrder:

    # as method decorator

    @override_autonow
    def test_with_method_decorator(self):
        order = Order.objects.create(
            amount=200,
            status='PAID',
            created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
            updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
        )

        # test order

    def test_with_context_manager(self):

        # as context manager

        with override_autonow():
            order_without_autonow = Order.objects.create(
                amount=200,
                status='PAID',
                created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
                updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
            )

        order_with_autonow = Order.objects.create(
            amount=200,
            status='PAID',
        )

        # test order


# as class decorator

@override_autonow
@pytest.mark.django_db
class TestWithClassDecorator:
    def test_with_class_decorator(self):
        order = Order.objects.create(
            amount=200,
            status='PAID',
            created_time=timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59),
            updated_time=timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0),
        )

        # test order

Override specific targets:

from django.test import TestCase

from override_autonow import override_autonow

from .models import Order


class TestOrder(TestCase):
    @override_autonow(exclude_auto_now=True)
    def test_exclude_auto_now_option(self):
        # Override only auto_now_add option
        ...

    @override_autonow(exclude_auto_now_add=True)
    def test_exclude_auto_now_add_option(self):
        # Override only auto_now option
        ...

    @override_autonow(exclude_date_field=True)
    def test_exclude_date_field(self):
        # Override only DateTimeField
        ...

    @override_autonow(exclude_datetime_field=True)
    def test_exclude_datetime_field(self):
        # Override only DateField
        ...

    @override_autonow(exclude_field_names={'created_time'})
    def test_exclude_field_names(self):
        # Override except fields named created_time
        ...

    @override_autonow(exclude_models=(Order,))
    def test_exclude_models(self):
        # Override except the Order model
        ...

    @override_autonow(override_field_names={'created_time'})
    def test_override_field_names(self):
        # Override only fields named created_time
        ...

    @override_autonow(override_models=(Order,))
    def test_override_models(self):
        # Override only the Order model
        ...

Test with factory-bot:

from django.test import TestCase
from django.utils import timezone
from factory.django import DjangoModelFactory

from override_autonow import override_autonow

from .models import Order


class OrderFactory:
    class Meta:
        model = Order

    amount = 200,
    status = 'PAID',
    created_time = timezone.datetime(year=2022, month=1, day=1, hour=23, minute=59, second=59)
    updated_time = timezone.datetime(year=2022, month=1, day=2, hour=0, minute=0, second=0)


class TestOrder(TestCase):
    @override_autonow
    def test_with_method_decorator(self):

        # Override created_time and updated_time with factory

        order = OrderFactory()

        # test order