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, serialized_rollback=False, available_apps=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 thedb
,transactional_db
ordjango_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. Withtransaction=False
(the default when not specified), transaction operations are noops during the test. This is the same behavior thatdjango.test.TestCase
uses. Whentransaction=True
, the behavior will be the same asdjango.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 toFalse
. Must be used together withtransaction=True
to have an effect. Please be aware that not all databases support this feature. For details seedjango.test.TransactionTestCase.reset_sequences
.databases (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 thedefault
database. The special value"__all__"
may be use to specify all configured databases. For details seedjango.test.TransactionTestCase.databases
anddjango.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. Settingserialized_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.
available_apps (Iterable[str] | None) –
Caution
This argument is experimental and is subject to change without deprecation.
The
available_apps
argument defines a subset of apps that are enabled for a specific set of tests. Settingavailable_apps
configures models for which types/permissions will be created before each test, and which model tables will be emptied after each test (this truncation may cascade to unavailable apps models).For details see
django.test.TransactionTestCase.available_apps
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’sTestCase.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_user(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']
If you use type annotations, you can annotate the fixture like this:
from pytest_django import DjangoAssertNumQueries
def test_num_queries(
django_assert_num_queries: DjangoAssertNumQueries,
):
...
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')
If you use type annotations, you can annotate the fixture like this:
from pytest_django import DjangoAssertNumQueries
def test_max_num_queries(
django_assert_max_num_queries: DjangoAssertNumQueries,
):
...
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.
Added 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'
If you use type annotations, you can annotate the fixture like this:
from pytest_django import DjangoCaptureOnCommitCallbacks
def test_on_commit(
django_capture_on_commit_callbacks: DjangoCaptureOnCommitCallbacks,
):
...
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
.