Testing Basics¶

`pytest-django` Quick Start¶

pytest-django is a plugin for pytest that provides a set of useful tools for testing Django applications and projects. For more information see the pytest-django documentation.

To install pytest-django:

$ pip install -U pytest-django
...

The DJANGO_SETTINGS_MODULE environment variable must be defined and should point to the django settings module used for testing. There are different approaches towards configuration.

Use pytest.ini to define DJANGO_SETTINGS_MODULE variable:

# -- FILE: pytest.ini (or tox.ini)
[pytest]
DJANGO_SETTINGS_MODULE = myapp.tests.settings
# -- recommended but optional:
python_files = tests.py test_*.py *_tests.py

Set DJANGO_SETTINGS_MODULE environment variable, e.g. in bash or Windows Command prompt
$ export DJANGO_SETTINGS_MODULE = myapp.tests.settings $ pytest

Use pytest_configure hook

# -- FILE: conftest.py
import os
from pathlib import Path
import sys
import django

TESTS_DIR = Path(__file__).resolve().parent
BASE_DIR = TESTS_DIR.parent
sys.path.insert(0, BASE_DIR.absolute())

def pytest_configure():
    os.environ['DJANGO_SETTINGS_MODULE'] = 'myapp.tests.settings'
    django.setup()

See also pytest_configure hook

Use --ds=SETTING command line option
$ pytest --ds=myapp.tests.settings
Variant to this method is to add the command line option to pytest.ini:
addopts = --ds=myapp.tests.settings

How the setting is choosen? The precedence (from higher to lower) is as follows:

The command line option --ds
The command line option --ds from pytest.ini or tox.ini
The environment variable DJANGO_SETTINGS_MODULE
The DJANGO_SETTINGS_MODULE option in the configuration file - pytest.ini (tox.ini)

To override settings you can use the setting fixutre.

@pytest.fixture(autouse=True)
def use_dummy_cache_backend(settings):
    settings.CACHES = {
        "default": {
            "BACKEND": "django.core.cache.backends.dummy.DummyCache",
        }
    }

`settings` module for testing¶

import os

# Define environment variables for testing
os.environ['DJANGO_SECRET_KEY'] = 'secret-key'

# Get everything from production settings module
from myproj.settings import *

# Use in-memory database for better testing performance
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': ':memory:',
    }
}

Testing with database¶

In order for a test to have access to the database it must either be marked using the django_db() mark or request one of the db, transactional_db or django_db_reset_sequences fixtures. Otherwise the test will fail when trying to access the database.

pytest.mark.django_db is used to mark a test function as requiring the database. It will ensure the database is set up correctly for the test. Each test will run in its own transaction which will be rolled back at the end of the test. This behavior is the same as Django’s standard TestCase class.

@pytest.mark.django_db
def test_user_model():
    user = User(username='joe')
    assert str(user) == user

Testing with client¶

Use client fixture - An instance of a django.test.Client.

def test_with_client(client):
    response = client.get('/')
    assert response.status_code == 200

For situations where logged in user is required, following are useful:

admin_user fixture - An instance of a superuser, with username “admin” and password “password” (in case there is no “admin” user yet).
admin_client fixture - An instance of a django.test.Client, logged in as an admin user.
client.force_log() method

def test_authenticated(client, admin_user):
    client.force_login(admin_user)
    response = client.get('/admin/')
    assert response.status_code == 200

def test_authenticated(admin_client):
    response = client.get('/admin/')
    assert response.status_code == 200

Further information:

Django Cookbook documentation

Testing Basics¶

pytest-django Quick Start¶

settings module for testing¶

Testing with database¶

Testing with client¶

`pytest-django` Quick Start¶

`settings` module for testing¶