========== Unit tests ========== .. highlight:: console Django comes with a test suite of its own, in the ``tests`` directory of the code base. It's our policy to make sure all tests pass at all times. We appreciate any and all contributions to the test suite! The Django tests all use the testing infrastructure that ships with Django for testing applications. See :doc:`/topics/testing/overview` for an explanation of how to write new tests. .. _running-unit-tests: Running the unit tests ====================== Quickstart ---------- If you are on Python 2, you'll first need to install a backport of the ``unittest.mock`` module that's available in Python 3. See :ref:`running-unit-tests-dependencies` for details on installing `mock`_ and the other optional test dependencies. Running the tests requires a Django settings module that defines the databases to use. To make it easy to get started, Django provides and uses a sample settings module that uses the SQLite database. To run the tests:: $ git clone https://github.com/django/django.git django-repo $ cd django-repo/tests $ PYTHONPATH=..:$PYTHONPATH ./runtests.py .. admonition:: Windows users We recommend something like `Git Bash `_ to run the tests using the above approach. You can avoid typing the ``PYTHONPATH`` bit each time by adding your Django checkout to your ``PYTHONPATH`` or by installing the source checkout using pip. See :ref:`installing-development-version`. Having problems? See :ref:`troubleshooting-unit-tests` for some common issues. .. _running-unit-tests-settings: Using another ``settings`` module --------------------------------- The included settings module allows you to run the test suite using SQLite. If you want to test behavior using a different database (and if you're proposing patches for Django, it's a good idea to test across databases), you may need to define your own settings file. To run the tests with different settings, ensure that the module is on your ``PYTHONPATH`` and pass the module with ``--settings``. The :setting:`DATABASES` setting in any test settings module needs to define two databases: * A ``default`` database. This database should use the backend that you want to use for primary testing. * A database with the alias ``other``. The ``other`` database is used to establish that queries can be directed to different databases. As a result, this database can use any backend you want. It doesn't need to use the same backend as the ``default`` database (although it can use the same backend if you want to). It cannot be the same database as the ``default``. If you're using a backend that isn't SQLite, you will need to provide other details for each database: * The :setting:`USER` option needs to specify an existing user account for the database. That user needs permission to execute ``CREATE DATABASE`` so that the test database can be created. * The :setting:`PASSWORD` option needs to provide the password for the :setting:`USER` that has been specified. Test databases get their names by prepending ``test_`` to the value of the :setting:`NAME` settings for the databases defined in :setting:`DATABASES`. These test databases are deleted when the tests are finished. You will also need to ensure that your database uses UTF-8 as the default character set. If your database server doesn't use UTF-8 as a default charset, you will need to include a value for :setting:`CHARSET ` in the test settings dictionary for the applicable database. .. _runtests-specifying-labels: Running only some of the tests ------------------------------ Django's entire test suite takes a while to run, and running every single test could be redundant if, say, you just added a test to Django that you want to run quickly without running everything else. You can run a subset of the unit tests by appending the names of the test modules to ``runtests.py`` on the command line. For example, if you'd like to run tests only for generic relations and internationalization, type:: $ ./runtests.py --settings=path.to.settings generic_relations i18n How do you find out the names of individual tests? Look in ``tests/`` — each directory name there is the name of a test. If you just want to run a particular class of tests, you can specify a list of paths to individual test classes. For example, to run the ``TranslationTests`` of the ``i18n`` module, type:: $ ./runtests.py --settings=path.to.settings i18n.tests.TranslationTests Going beyond that, you can specify an individual test method like this:: $ ./runtests.py --settings=path.to.settings i18n.tests.TranslationTests.test_lazy_objects Running the Selenium tests -------------------------- Some tests require Selenium and a Web browser (Firefox, Google Chrome, or Internet Explorer). To allow those tests to be run rather than skipped, you must install the selenium_ package into your Python path and run the tests with the ``--selenium`` option:: $ ./runtests.py --settings=test_sqlite --selenium admin_inlines .. _running-unit-tests-dependencies: Running all the tests --------------------- If you want to run the full suite of tests, you'll need to install a number of dependencies: * bcrypt_ * docutils_ * geoip2_ * jinja2_ 2.7+ * numpy_ * Pillow_ * PyYAML_ * pytz_ * setuptools_ * memcached_, plus a :ref:`supported Python binding ` * mock_ (for Python 2) * gettext_ (:ref:`gettext_on_windows`) * selenium_ * sqlparse_ You can find these dependencies in `pip requirements files`_ inside the ``tests/requirements`` directory of the Django source tree and install them like so:: $ pip install -r tests/requirements/py3.txt # Python 2: py2.txt You can also install the database adapter(s) of your choice using ``oracle.txt``, ``mysql.txt``, or ``postgres.txt``. If you want to test the memcached cache backend, you'll also need to define a :setting:`CACHES` setting that points at your memcached instance. To run the GeoDjango tests, you will need to :doc:`setup a spatial database and install the Geospatial libraries`. Each of these dependencies is optional. If you're missing any of them, the associated tests will be skipped. .. _bcrypt: https://pypi.python.org/pypi/bcrypt .. _docutils: https://pypi.python.org/pypi/docutils .. _geoip2: https://pypi.python.org/pypi/geoip2 .. _jinja2: https://pypi.python.org/pypi/jinja2 .. _numpy: https://pypi.python.org/pypi/numpy .. _Pillow: https://pypi.python.org/pypi/Pillow/ .. _PyYAML: http://pyyaml.org/wiki/PyYAML .. _pytz: https://pypi.python.org/pypi/pytz/ .. _setuptools: https://pypi.python.org/pypi/setuptools/ .. _memcached: http://memcached.org/ .. _mock: https://pypi.python.org/pypi/mock .. _gettext: https://www.gnu.org/software/gettext/manual/gettext.html .. _selenium: https://pypi.python.org/pypi/selenium .. _sqlparse: https://pypi.python.org/pypi/sqlparse .. _pip requirements files: https://pip.pypa.io/en/latest/user_guide.html#requirements-files Code coverage ------------- Contributors are encouraged to run coverage on the test suite to identify areas that need additional tests. The coverage tool installation and use is described in :ref:`testing code coverage`. Coverage should be run in a single process to obtain accurate statistics. To run coverage on the Django test suite using the standard test settings:: $ coverage run ./runtests.py --settings=test_sqlite --parallel=1 After running coverage, generate the html report by running:: $ coverage html When running coverage for the Django tests, the included ``.coveragerc`` settings file defines ``coverage_html`` as the output directory for the report and also excludes several directories not relevant to the results (test code or external code included in Django). .. _contrib-apps: Contrib apps ============ Tests for contrib apps can be found in the ``tests/`` directory, typically under ``_tests``. For example, tests for ``contrib.auth`` are located in ``tests/auth_tests``. .. _troubleshooting-unit-tests: Troubleshooting =============== Many test failures with ``UnicodeEncodeError`` ---------------------------------------------- If the ``locales`` package is not installed, some tests will fail with a ``UnicodeEncodeError``. You can resolve this on Debian-based systems, for example, by running:: $ apt-get install locales $ dpkg-reconfigure locales Tests that only fail in combination ----------------------------------- In case a test passes when run in isolation but fails within the whole suite, we have some tools to help analyze the problem. The ``--bisect`` option of ``runtests.py`` will run the failing test while halving the test set it is run together with on each iteration, often making it possible to identify a small number of tests that may be related to the failure. For example, suppose that the failing test that works on its own is ``ModelTest.test_eq``, then using:: $ ./runtests.py --bisect basic.tests.ModelTest.test_eq will try to determine a test that interferes with the given one. First, the test is run with the first half of the test suite. If a failure occurs, the first half of the test suite is split in two groups and each group is then run with the specified test. If there is no failure with the first half of the test suite, the second half of the test suite is run with the specified test and split appropriately as described earlier. The process repeats until the set of failing tests is minimized. The ``--pair`` option runs the given test alongside every other test from the suite, letting you check if another test has side-effects that cause the failure. So:: $ ./runtests.py --pair basic.tests.ModelTest.test_eq will pair ``test_eq`` with every test label. With both ``--bisect`` and ``--pair``, if you already suspect which cases might be responsible for the failure, you may limit tests to be cross-analyzed by :ref:`specifying further test labels ` after the first one:: $ ./runtests.py --pair basic.tests.ModelTest.test_eq queries transactions You can also try running any set of tests in reverse using the ``--reverse`` option in order to verify that executing tests in a different order does not cause any trouble:: $ ./runtests.py basic --reverse Seeing the SQL queries run during a test ---------------------------------------- If you wish to examine the SQL being run in failing tests, you can turn on :ref:`SQL logging ` using the ``--debug-sql`` option. If you combine this with ``--verbosity=2``, all SQL queries will be output:: $ ./runtests.py basic --debug-sql .. versionadded:: 1.8 The ``--reverse`` and ``--debug-sql`` options were added. Seeing the full traceback of a test failure ------------------------------------------- By default tests are run in parallel with one process per core. When the tests are run in parallel, however, you'll only see a truncated traceback for any test failures. You can adjust this behavior with the ``--parallel`` option:: $ ./runtests.py basic --parallel=1 You can also use the ``DJANGO_TEST_PROCESSES`` environment variable for this purpose. .. versionadded:: 1.9 Support for running tests in parallel and the ``--parallel`` option were added.