bradleyayers/django-attest

Attest integration for Django

django-attest

An alternative testing framework for Django, based on Attest.

Attempts to provide a more Pythonic testing API than unittest. Useful testing features in recent version of Django have been included for use with older version.

Installation

Requires:

• Django ≥1.2.
• Attest >= 0.6 (use master)

Use pip:

pip install django-attest

On Django ≥1.3, a custom test runner can be used:

TEST_RUNNER = "django_attest.Runner"

Usage

Create some tests, then run them (replace tests.settings with your own):

DJANGO_SETTINGS_MODULE=tests.settings attest -r django

Create a test collection and optionally include one of django-attest's test contexts. The result is that a client argument is passed to each test within the collection. client is a django.test.TestClient object and allows you to make HTTP requests to your project.

from attest import Tests
from django_attest import TestContext

tests = Tests()
tests.context(TestContext())

@tests.test
def can_add(client):
    client.get('/some-url/')  # same as self.client.get() if you were using
                              # django.test.TestCase

See the TestCase.client documentation for more details.

When using a django.test.TestCase subclass, you're able to specify various options that affect the environment in which your tests are executed. django-attest provides the same functionality via keyword arguments to the TestContext. The following keyword arguments are supported:

• fixtures -- http://docs.djangoproject.com/en/1.3/topics/testing/#django.test.TestCase.fixtures
• urls -- http://docs.djangoproject.com/en/1.3/topics/testing/#django.test.TestCase.urls
• client_class -- http://docs.djangoproject.com/en/1.3/topics/testing/#django.test.TestCase.client_class
• multi_db -- http://docs.djangoproject.com/en/1.3/topics/testing/#django.test.TestCase.multi_db

For example if you want to specify fixtures, urls, a client_class, or multi_db, simply pass in these options when creating the django_tables.TestContext object:

from attest import Tests
from django_attest import TestContext

tests = Tests()
tests.context(TestContext(fixtures=['testdata.json'], urls='myapp.urls'))

Transaction management in tests

If you need to test transaction management within your tests, use TransactionTestContext rather than TestContext, e.g.:

from attest import Tests
from django_attest import TransactionTestContext

tests = Tests()
tests.context(TransactionTestContext())

@tests.test
def some_test(client):
    # test something
    ...

Testing a reusable Django app

A flexible approach is to create a tests Django project. This shouldn't be the fully-fledged output of django-admin.py startproject, but instead the minimum required to keep Django happy.

tests/__init__.py

from attest import Tests


suite = Tests()


@suite.test
def example():
    assert len("abc") == 3

Django's built-in test runner performs various environment initialisation and cleanup tasks. It's important that tests are run using one of the loaders from django-attest.

tests/settings.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': ':memory:',
    }
}

INSTALLED_APPS = [
    'django.contrib.sessions',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'my_reusable_app',
]

SECRET_KEY = 'abcdefghiljklmnopqrstuvwxyz'

ROOT_URLCONF = 'tests.urls'

tests/urls.py

from django.conf.urls import patterns
urlpatterns = patterns('')

Testing non-reusable apps in a Django project

To test non-reusable apps in a Django project, the app must contain either a tests or models module with either a suite function that returns a unittest.TestCase, or simply contains TestCase classes. (see Django's documentation for details).

As of Attest 0.6 you should use test cases:

# myapp/tests.py
from attest import Tests

template = Tests()

@template.test
def filter():
    # ...

template = template.test_case()

This allows Django to find your tests, and allows you to run individual tests, e.g.:

python manage.py test myapp.template.test_filter

Note

When a unittest.TestCase is created from a test collection, the function names are prefixed with test_.

Prior to Attest 0.6, you must use the test suite option, which unfortunately doesn't support running individual tests:

from attest import Tests

template = Tests()

@template.test
def filter():
    # ...

suite = template.test_suite

assert hook

Since Django uses manage.py as its entry point, django-attest enables the assert hook automatically when it's first imported.

This means that you need to do the following:

1. Make sure django_attest is imported as soon as possible.
2. Add from attest import assert_hook to the top of each test module.

Django assertions

For details on each of these, see django_attest/assertion.py.

redirects

Assert that a response redirects to some resource:

from django_attest import redirects

response = client.get('/')
redirects(response, url="http://example.com:8000/foo/?key=value#frag")
redirects(response, scheme="http")
redirects(response, domain="example.com")
redirects(response, port="8000")
redirects(response, path="/foo/")
redirects(response, query="key=value")
redirects(response, fragment="frag")

Each component can only be asserted if it exists explicitly in the URL, e.g.

with attest.raises(AssertionError):

redirects(client.get('/'), port=80) # port is rarely explicit

queries

Assert an expected set of queries took place:

from django_attest import queries

with queries() as qs:
    User.objects.count()
assert len(qs) == 5

# The same could be rewritten as
with queries(count=5):
    User.objects.count()

Context managers

django-attest has some context managers to simplify common tasks:

settings(**settings)

Change global settings within a block, same functionality as Django 1.4's TestCase.settings:

from django_attest import settings

with settings(MEDIA_ROOT="/tmp"):
    # ...

Code that's sensitive to settings changes should use the django_attest.signals.setting_changed signal to overcome any assumptions of settings remaining constant.

Note

On Django >=1.4, django_attest.signals.setting_changed is an alias of django.test.signals.setting_changed.

translation(language_code, deactivate=False)

Activate a specific translation/language. The semantics are the same as Django 1.4's django.utils.translation.override:

from django_attest import translation
from django.utils.translation import ugettext

with translation('de'):
    assert ugettext('the apple') == 'der Apfel'

urlconf(patterns)

Takes a list of URL patterns and promotes them up as the root URLconf. This avoids the need to have a dedicated test project and urls.py for simple cases:

@suite.test
def foo(client):
    def view(request):
        return HttpResponse('success')

    urls = patterns('', (r'view/', view))
    with urlconf(urls):
        assert client.get(reverse(view)).content == 'success'

If you want to provide a dotted path to a urls.py, use settings(ROOT_URLCONF=...) instead, it takes care to clear URL resolver caches.

Backports

• django_attest.RequestFactory (from Django 1.4)
• django_attest.settings (override_settings inspired from Django 1.4)
• django_attest.translation (django.utils.translation.override port from Django 1.4)

Changelog

v0.10.0

• Add translation context manager
• Add Travis CI testing

v0.9.1

• Fix requirements for Attest

v0.9.0

• Setting up the Django environment is no longer part of the distuils loader, rather it's builtin to the django-attest reporters.
• Declare reporter entry points (named django-...)

v0.8.1

• Make test runner compatible with Python 2.6
• Add support for Python 3.2

v0.8.0

• Add test runner to show proper Attest formatting of assertion errors