Horizon’s tests and you

How to run the tests

Because Horizon is composed of both the horizon app and the openstack_dashboard reference project, there are in fact two sets of unit tests. While they can be run individually without problem, there is an easier way:

Included at the root of the repository is the tox.ini config which invokes both sets of tests, and optionally generates analyses on both components in the process. tox is what Jenkins uses to verify the stability of the project, so you should make sure you run it and it passes before you submit any pull requests/patches.

To run all tests:

$ tox

It’s also possible to run a subset of the tests. Open tox.ini in the Horizon root directory to see a list of test environments. You can read more about tox in general at https://tox.readthedocs.io/en/latest/.

By default running the Selenium tests will open your Firefox browser (you have to install it first, else an error is raised), and you will be able to see the tests actions:

$ tox -e selenium

If you want to run the suite headless, without being able to see them (as they are ran on Jenkins), you can run the tests:

$ tox -e selenium-headless

Selenium will use a virtual display in this case, instead of your own. In order to run the tests this way you have to install the dependency xvfb, like this:

$ sudo apt-get install xvfb

for a Debian OS flavour, or for Fedora/Red Hat flavours:

$ sudo yum install xorg-x11-server-Xvfb

If you can’t run a virtual display, or would prefer not to, you can use the PhantomJS web driver instead:

$ tox -e selenium-phantomjs

If you need to install PhantomJS, you may do so with npm like this:

$ npm -g install phantomjs

Alternatively, many distributions have system packages for PhantomJS, or it can be downloaded from http://phantomjs.org/download.html.

tox Test Environments

This is a list of test environments available to be executed by tox -e <name>.


Runs pep8, which is a tool that checks Python code style. You can read more about pep8 at https://www.python.org/dev/peps/pep-0008/


Runs the Python unit tests against the current default version of Django with Python 2.7 environment. Check requirements.txt in horizon repository to know which version of Django is actually used.

All other dependencies are as defined by the upper-constraints file at https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt

You can run a subset of the tests by passing the test path as an argument to tox:

$ tox -e py27 -- openstack_dashboard.dashboards.identity.users.tests

The following is more example to run a specific test class and a specific test:

$ tox -e py27 -- openstack_dashboard.dashboards.identity.users.tests:UsersViewTests
$ tox -e py27 -- openstack_dashboard.dashboards.identity.users.tests:UsersViewTests.test_index

You can also pass other arguments. For example, to drop into a live debugger when a test fails you can use:

$ tox -e py27 -- --pdb

py27dj18, py27dj19, py27dj110

Runs the Python unit tests against Django 1.8, Django 1.9 and Django 1.10 respectively


Runs the Python unit tests with a Python 3.5 environment.


Outputs Horizons release notes as HTML to releasenotes/build/html.

Also takes an alternative builder as an optional argument, such as tox -e docs -- <builder>, which will output to releasenotes/build/<builder>. Available builders are listed at http://www.sphinx-doc.org/en/latest/builders.html


Installs the npm dependencies listed in package.json and runs the JavaScript tests. Can also take optional arguments, which will be executed as an npm script following the dependency install, instead of test.


$ tox -e npm -- lintq


Outputs Horizons documentation as HTML to doc/build/html.

Also takes an alternative builder as an optional argument, such as tox -e docs -- <builder>, which will output to doc/build/<builder>. Available builders are listed at http://www.sphinx-doc.org/en/latest/builders.html


$ tox -e docs -- latexpdf

Writing tests

Horizon uses Django’s unit test machinery (which extends Python’s unittest2 library) as the core of its test suite. As such, all tests for the Python code should be written as unit tests. No doctests please.

In general new code without unit tests will not be accepted, and every bugfix must include a regression test.

For a much more in-depth discussion of testing, see the testing topic guide.