# 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 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 (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.

    - 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. Setting `available_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’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_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, *, using=None)
  Parameters:

    - num – expected number of queries

    - connection – optional database connection

    - info (str) – optional info message to display on failure

    - using (str) – optional database alias

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, *, using=None)
  Parameters:

    - num – expected maximum number of queries

    - connection – optional database connection

    - info (str) – optional info message to display on failure

    - using (str) – optional database alias

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`.