Django helpers

Assertions

All of Django’s TestCase Assertions are available in pytest_django.asserts, e.g.

from pytest_django.asserts import assertTemplateUsed

Markers

pytest-django registers and uses markers. See the pytest documentation on what marks are and for notes on using them. Remember that you can apply marks at the single test level, the class level, the module level, and dynamically in a hook or fixture.

`pytest.mark.django_db` - request database access

pytest.mark.django_db([transaction=False, reset_sequences=False, databases=None])

This 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.

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.

Parameters:

transaction (bool) – The transaction argument will allow the test to use real transactions. With transaction=False (the default when not specified), transaction operations are noops during the test. This is the same behavior that django.test.TestCase uses. When transaction=True, the behavior will be the same as django.test.TransactionTestCase.
reset_sequences (bool) – The reset_sequences argument will ask to reset auto increment sequence values (e.g. primary keys) before running the test. Defaults to False. Must be used together with transaction=True to have an effect. Please be aware that not all databases support this feature. For details see django.test.TransactionTestCase.reset_sequences.
databases (Union[Iterable[str], str, None]) –

Caution

This argument is experimental and is subject to change without deprecation. We are still figuring out the best way to expose this functionality. If you are using this successfully or unsuccessfully, let us know!

The databases argument defines which databases in a multi-database configuration will be set up and may be used by the test. Defaults to only the default database. The special value "__all__" may be use to specify all configured databases. For details see django.test.TransactionTestCase.databases and django.test.TestCase.databases.
serialized_rollback (bool) –
The serialized_rollback argument enables rollback emulation. After a transactional test (or any test using a database backend which doesn’t support transactions) runs, the database is flushed, destroying data created in data migrations. Setting serialized_rollback=True tells Django to serialize the database content during setup, and restore it during teardown.

Note that this will slow down that test suite by approximately 3x.

Note

If you want access to the Django database inside a fixture, this marker may or may not help even if the function requesting your fixture has this marker applied, depending on pytest’s fixture execution order. To access the database in a fixture, it is recommended that the fixture explicitly request one of the db, transactional_db, django_db_reset_sequences or django_db_serialized_rollback fixtures. See below for a description of them.

Note

Automatic usage with django.test.TestCase.

Test classes that subclass django.test.TestCase will have access to the database always to make them compatible with existing Django tests. Test classes that subclass Python’s unittest.TestCase need to have the marker applied in order to access the database.

`pytest.mark.urls` - override the urlconf

pytest.mark.urls(urls)

Specify a different settings.ROOT_URLCONF module for the marked tests.

Parameters:: urls (str) – The urlconf module to use for the test, e.g. myapp.test_urls. This is similar to Django’s TestCase.urls attribute.

Example usage:

@pytest.mark.urls('myapp.test_urls')
def test_something(client):
    assert b'Success!' in client.get('/some_url_defined_in_test_urls/').content

`pytest.mark.ignore_template_errors` - ignore invalid template variables

pytest.mark.ignore_template_errors()

Ignore errors when using the --fail-on-template-vars option, i.e. do not cause tests to fail if your templates contain invalid variables.

This marker sets the string_if_invalid template option. See How invalid variables are handled.

Example usage:

@pytest.mark.ignore_template_errors
def test_something(client):
    client('some-url-with-invalid-template-vars')

Fixtures

pytest-django provides some pytest fixtures to provide dependencies for tests. More information on fixtures is available in the pytest documentation.

`rf` - `RequestFactory`

An instance of a django.test.RequestFactory.

Example

from myapp.views import my_view

def test_details(rf, admin_user):
    request = rf.get('/customer/details')
    # Remember that when using RequestFactory, the request does not pass
    # through middleware. If your view expects fields such as request.user
    # to be set, you need to set them explicitly.
    # The following line sets request.user to an admin user.
    request.user = admin_user
    response = my_view(request)
    assert response.status_code == 200

`async_rf` - `AsyncRequestFactory`

An instance of a django.test.AsyncRequestFactory.

Example

This example uses pytest-asyncio.

from myapp.views import my_view

@pytest.mark.asyncio
async def test_details(async_rf):
    request = await async_rf.get('/customer/details')
    response = my_view(request)
    assert response.status_code == 200

`client` - `django.test.Client`

An instance of a django.test.Client.

Example

def test_with_client(client):
    response = client.get('/')
    assert response.content == 'Foobar'

To use client as an authenticated standard user, call its force_login() or login() method before accessing a URL:

def test_with_authenticated_client(client, django_user_model):
    username = "user1"
    password = "bar"
    user = django_user_model.objects.create_user(username=username, password=password)
    # Use this:
    client.force_login(user)
    # Or this:
    client.login(username=username, password=password)
    response = client.get('/private')
    assert response.content == 'Protected Area'

`async_client` - `django.test.AsyncClient`

An instance of a django.test.AsyncClient.

Example

This example uses pytest-asyncio.

@pytest.mark.asyncio
async def test_with_async_client(async_client):
    response = await async_client.get('/')
    assert response.content == 'Foobar'

`admin_client` - `django.test.Client` logged in as admin

An instance of a django.test.Client, logged in as an admin user.

Example

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

Using the admin_client fixture will cause the test to automatically be marked for database use (no need to specify the django_db() mark).

`admin_user` - an admin user (superuser)

An instance of a superuser, with username “admin” and password “password” (in case there is no “admin” user yet).

Using the admin_user fixture will cause the test to automatically be marked for database use (no need to specify the django_db() mark).

`django_user_model`

A shortcut to the User model configured for use by the current Django project (aka the model referenced by settings.AUTH_USER_MODEL). Use this fixture to make pluggable apps testable regardless what User model is configured in the containing Django project.

Example

def test_new_user(django_user_model):
    django_user_model.objects.create(username="someone", password="something")

`django_username_field`

This fixture extracts the field name used for the username on the user model, i.e. resolves to the user model’s USERNAME_FIELD. Use this fixture to make pluggable apps testable regardless what the username field is configured to be in the containing Django project.

`db`

This fixture will ensure the Django database is set up. Only required for fixtures that want to use the database themselves. A test function should normally use the pytest.mark.django_db() mark to signal it needs the database. This fixture does not return a database connection object. When you need a Django database connection or cursor, import it from Django using from django.db import connection.

`transactional_db`

This fixture can be used to request access to the database including transaction support. This is only required for fixtures which need database access themselves. A test function should normally use the pytest.mark.django_db() mark with transaction=True to signal it needs the database.

`django_db_reset_sequences`

This fixture provides the same transactional database access as transactional_db, with additional support for reset of auto increment sequences (if your database supports it). This is only required for fixtures which need database access themselves. A test function should normally use the pytest.mark.django_db() mark with transaction=True and reset_sequences=True.

`django_db_serialized_rollback`

This fixture triggers rollback emulation. This is only required for fixtures which need to enforce this behavior. A test function should normally use pytest.mark.django_db() with serialized_rollback=True (and most likely also transaction=True) to request this behavior.

`live_server`

This fixture runs a live Django server in a background thread. The server’s URL can be retrieved using the live_server.url attribute or by requesting it’s string value: str(live_server). You can also directly concatenate a string to form a URL: live_server + '/foo'.

Since the live server and the tests run in different threads, they cannot share a database transaction. For this reason, live_server depends on the transactional_db fixture. If tests depend on data created in data migrations, you should add the django_db_serialized_rollback fixture.

Note

Combining database access fixtures.

When using multiple database fixtures together, only one of them is used. Their order of precedence is as follows (the last one wins):

db
transactional_db

In addition, using live_server or django_db_reset_sequences will also trigger transactional database access, and django_db_serialized_rollback regular database access, if not specified.

`settings`

This fixture will provide a handle on the Django settings module, and automatically revert any changes made to the settings (modifications, additions and deletions).

Example

def test_with_specific_settings(settings):
    settings.USE_TZ = True
    assert settings.USE_TZ

`django_assert_num_queries`

django_assert_num_queries(num, connection=None, info=None)

Parameters:

num – expected number of queries
connection – optional non-default DB connection
info (str) – optional info message to display on failure

This fixture allows to check for an expected number of DB queries.

If the assertion failed, the executed queries can be shown by using the verbose command line option.

It wraps django.test.utils.CaptureQueriesContext and yields the wrapped CaptureQueriesContext instance.

Example usage:

def test_queries(django_assert_num_queries):
    with django_assert_num_queries(3) as captured:
        Item.objects.create('foo')
        Item.objects.create('bar')
        Item.objects.create('baz')

    assert 'foo' in captured.captured_queries[0]['sql']

`django_assert_max_num_queries`

django_assert_max_num_queries(num, connection=None, info=None)

Parameters:

num – expected maximum number of queries
connection – optional non-default DB connection
info (str) – optional info message to display on failure

This fixture allows to check for an expected maximum number of DB queries.

It is a specialized version of django_assert_num_queries.

Example usage:

def test_max_queries(django_assert_max_num_queries):
    with django_assert_max_num_queries(2):
        Item.objects.create('foo')
        Item.objects.create('bar')

`django_capture_on_commit_callbacks`

django_capture_on_commit_callbacks(*, using=DEFAULT_DB_ALIAS, execute=False)

Parameters:

using – The alias of the database connection to capture callbacks for.
execute – If True, all the callbacks will be called as the context manager exits, if no exception occurred. This emulates a commit after the wrapped block of code.

New in version 4.4.

Returns a context manager that captures transaction.on_commit() callbacks for the given database connection. It returns a list that contains, on exit of the context, the captured callback functions. From this list you can make assertions on the callbacks or call them to invoke their side effects, emulating a commit.

Avoid this fixture in tests using transaction=True; you are not likely to get useful results.

This fixture is based on Django’s django.test.TestCase.captureOnCommitCallbacks() helper.

Example usage:

def test_on_commit(client, mailoutbox, django_capture_on_commit_callbacks):
    with django_capture_on_commit_callbacks(execute=True) as callbacks:
        response = client.post(
            '/contact/',
            {'message': 'I like your site'},
        )

    assert response.status_code == 200
    assert len(callbacks) == 1
    assert len(mailoutbox) == 1
    assert mailoutbox[0].subject == 'Contact Form'
    assert mailoutbox[0].body == 'I like your site'

`mailoutbox`

A clean email outbox to which Django-generated emails are sent.

Example

from django.core import mail

def test_mail(mailoutbox):
    mail.send_mail('subject', 'body', 'from@example.com', ['to@example.com'])
    assert len(mailoutbox) == 1
    m = mailoutbox[0]
    assert m.subject == 'subject'
    assert m.body == 'body'
    assert m.from_email == 'from@example.com'
    assert list(m.to) == ['to@example.com']

This uses the django_mail_patch_dns fixture, which patches DNS_NAME used by django.core.mail with the value from the django_mail_dnsname fixture, which defaults to “fake-tests.example.com”.

Automatic cleanup

pytest-django provides some functionality to assure a clean and consistent environment during tests.

Clearing of site cache

If django.contrib.sites is in your INSTALLED_APPS, Site cache will be cleared for each test to avoid hitting the cache and causing the wrong Site object to be returned by Site.objects.get_current().

Clearing of mail.outbox

mail.outbox will be cleared for each pytest, to give each new test an empty mailbox to work with. However, it’s more “pytestic” to use the mailoutbox fixture described above than to access mail.outbox.

Django helpers

Assertions

Markers

pytest.mark.django_db - request database access

pytest.mark.urls - override the urlconf

pytest.mark.ignore_template_errors - ignore invalid template variables

Fixtures

rf - RequestFactory

Example

async_rf - AsyncRequestFactory

Example

client - django.test.Client

Example

async_client - django.test.AsyncClient

Example

admin_client - django.test.Client logged in as admin

Example

admin_user - an admin user (superuser)

django_user_model

Example

django_username_field

db

transactional_db

django_db_reset_sequences

django_db_serialized_rollback

live_server

settings

Example

django_assert_num_queries

django_assert_max_num_queries

django_capture_on_commit_callbacks

mailoutbox

Example

Automatic cleanup

Clearing of site cache

Clearing of mail.outbox

`pytest.mark.django_db` - request database access

`pytest.mark.urls` - override the urlconf

`pytest.mark.ignore_template_errors` - ignore invalid template variables

`rf` - `RequestFactory`

`async_rf` - `AsyncRequestFactory`

`client` - `django.test.Client`

`async_client` - `django.test.AsyncClient`

`admin_client` - `django.test.Client` logged in as admin

`admin_user` - an admin user (superuser)

`django_user_model`

`django_username_field`

`db`

`transactional_db`

`django_db_reset_sequences`

`django_db_serialized_rollback`

`live_server`

`settings`

`django_assert_num_queries`

`django_assert_max_num_queries`

`django_capture_on_commit_callbacks`

`mailoutbox`