saltstack/salt

.. _salt-test-suite:

=================
Salt's Test Suite
=================

Salt comes with a powerful integration and unit test suite allowing for
the fully automated run of integration and/or unit tests from a single
interface.

To learn the basics of how Salt's test suite works, be sure to check
out the :ref:`Salt's Test Suite: An Introduction <tutorial-salt-testing>`
tutorial.


Test Directory Structure
========================

Salt's test suite is located in the ``tests`` directory in the root of
Salt's codebase. The test suite is divided into two main groups:

* :ref:`Integration Tests <integration-tests>`
* :ref:`Unit Tests <unit-tests>`

Within each of these groups, the directory structure roughly mirrors the
structure of Salt's own codebase. Notice that there are directories for
``states``, ``modules``, ``runners``, ``output``, and more in each testing
group.

The files that are housed in the ``modules`` directory of either the unit
or the integration testing factions contain respective integration or unit
test files for Salt execution modules.


.. note::
    Salt's test framework provides for the option to only run tests which
    correspond to a given file (or set of files), via the ``--from-filenames``
    argument to ``runtests.py``:

    .. code-block:: bash

        python /path/to/runtests.py --from-filenames=salt/modules/foo.py

    Therefore, where possible, test files should be named to match the source
    files they are testing. For example, when writing tests for
    ``salt/modules/foo.py``, unit tests should go into
    ``tests/unit/modules/test_foo.py``, and integration tests should go into
    ``tests/integration/modules/test_foo.py``.

    However, integration tests are organized differently from unit tests, and
    this may not always be plausible. In these cases, to ensure that the proper
    tests are run for these files, they must be mapped in
    `tests/filename_map.yml`__.

    The filename map is used to supplement the test framework's filename
    matching logic. This allows one to ensure that states correspnding to an
    execution module are also tested when ``--from-filenames`` includes that
    execution module. It can also be used for those cases where the path to a
    test file doesn't correspond directly to the file which is being tested
    (e.g. the ``shell``, ``spm``, and ``ssh`` integration tests, among others).
    Both glob expressions and regular expressions are permitted in the filename
    map.


    .. important::
        Test modules which don't map directly to the source file they are
        testing (using the naming convention described above), **must** be
        added to the ``ignore`` tuple in ``tests/unit/test_module_names.py``,
        in the ``test_module_name_source_match`` function. This unit test
        ensures that we maintain the naming convention for test files.

    .. __: https://github.com/saltstack/salt/blob/develop/tests/filename_map.yml


Integration Tests
-----------------

The Integration section of Salt's test suite start up a number of Salt
daemons to test functionality in a live environment. These daemons
include two Salt Masters, one Syndic, and two Minions. This allows the
Syndic interface to be tested and Master/Minion communication to be
verified. All of the integration tests are executed as live Salt commands
sent through the started daemons.

Integration tests are particularly good at testing modules, states, and
shell commands, among other segments of Salt's ecosystem. By utilizing
the integration test daemons, integration tests are easy to write. They
are also SaltStack's generally preferred method of adding new tests.

The discussion in the :ref:`Integration vs. Unit <integration-vs-unit>`
section of the :ref:`testing tutorial <tutorial-salt-testing>` is
beneficial in learning why you might want to write integration tests
vs. unit tests. Both testing arenas add value to Salt's test suite and
you should consider adding both types of tests if possible and appropriate
when contributing to Salt.

* :ref:`Integration Test Documentation <integration-tests>`


Unit Tests
----------

Unit tests do not spin up any Salt daemons, but instead find their value
in testing singular implementations of individual functions. Instead of
testing against specific interactions, unit tests should be used to test
a function's logic as well as any ``return`` or ``raises`` statements.
Unit tests also rely heavily on mocking external resources.

The discussion in the :ref:`Integration vs. Unit <integration-vs-unit>`
section of the :ref:`testing tutorial <tutorial-salt-testing>` is useful
in determining when you should consider writing unit tests instead of,
or in addition to, integration tests when contributing to Salt.

* :ref:`Unit Test Documentation <unit-tests>`


.. _running-the-tests:

Running The Tests
=================

There are requirements, in addition to Salt's requirements, which
need to be installed in order to run the test suite. Install one of
the lines below, depending on the relevant Python version:

.. code-block:: bash

    pip install -r requirements/dev_python27.txt
    pip install -r requirements/dev_python34.txt

To be able to run integration tests which utilizes ZeroMQ transport, you also
need to install additional requirements for it. Make sure you have installed
the C/C++ compiler and development libraries and header files needed for your
Python version.

This is an example for RedHat-based operating systems:

.. code-block:: bash

    yum install gcc gcc-c++ python-devel
    pip install -r requirements/zeromq.txt

On Debian, Ubuntu or their derivatives run the following commands:

.. code-block:: bash

    apt-get install build-essential python-dev
    pip install -r requirements/zeromq.txt

This will install the latest ``pycrypto`` and ``pyzmq`` (with bundled
``libzmq``) Python modules required for running integration tests suite.

Once all requirements are installed, use ``runtests.py`` script to run all of
the tests included in Salt's test suite:

.. code-block:: bash

    python tests/runtests.py

For more information about options you can pass the test runner, see the
``--help`` option:

.. code-block:: bash

    python tests/runtests.py --help

An alternative way of invoking the test suite is available in ``setup.py``:

.. code-block:: bash

    ./setup.py test


.. _running-test-subsections:

Running Test Subsections
------------------------

Instead of running the entire test suite all at once, which can take a long time,
there are several ways to run only specific groups of tests or individual tests:

* Run :ref:`unit tests only<running-unit-tests-no-daemons>`: ``python tests/runtests.py --unit-tests``
* Run unit and integration tests for states: ``python tests/runtests.py --state``
* Run integration tests for an individual module: ``python tests/runtests.py -n integration.modules.virt``
* Run unit tests for an individual module: ``python tests/runtests.py -n unit.modules.virt_test``
* Run an individual test by using the class and test name (this example is for the
  ``test_default_kvm_profile`` test in the ``integration.module.virt``):
  ``python tests/runtests.py -n integration.module.virt.VirtTest.test_default_kvm_profile``

For more specific examples of how to run various test subsections or individual
tests, please see the :ref:`Test Selection Options <test-selection-options>`
documentation or the :ref:`Running Specific Tests <running-specific-tests>`
section of the :ref:`Salt's Test Suite: An Introduction <tutorial-salt-testing>`
tutorial.


.. _running-unit-tests-no-daemons:

Running Unit Tests Without Integration Test Daemons
---------------------------------------------------

Since the unit tests do not require a master or minion to execute, it is often useful to be able to
run unit tests individually, or as a whole group, without having to start up the integration testing
daemons. Starting up the master, minion, and syndic daemons takes a lot of time before the tests can
even start running and is unnecessary to run unit tests. To run unit tests without invoking the
integration test daemons, simply run the ``runtests.py`` script with ``--unit`` argument:

.. code-block:: bash

    python tests/runtests.py --unit

All of the other options to run individual tests, entire classes of tests, or
entire test modules still apply.


Running Destructive Integration Tests
-------------------------------------

Salt is used to change the settings and behavior of systems. In order to
effectively test Salt's functionality, some integration tests are written to
make actual changes to the underlying system. These tests are referred to as
"destructive tests". Some examples of destructive tests are changes may be
testing the addition of a user or installing packages. By default,
destructive tests are disabled and will be skipped.

Generally, destructive tests should clean up after themselves by attempting to
restore the system to its original state. For instance, if a new user is created
during a test, the user should be deleted after the related test(s) have
completed. However, no guarantees are made that test clean-up will complete
successfully. Therefore, running destructive tests should be done with caution.

.. note::

    Running destructive tests will change the underlying system.
    Use caution when running destructive tests.

To run tests marked as destructive, set the ``--run-destructive`` flag:

.. code-block:: bash

    python tests/runtests.py --run-destructive


Running Cloud Provider Tests
----------------------------

Salt's testing suite also includes integration tests to assess the successful
creation and deletion of cloud instances using :ref:`Salt-Cloud<salt-cloud>` for
providers supported by Salt-Cloud.

The cloud provider tests are off by default and run on sample configuration files
provided in ``tests/integration/files/conf/cloud.providers.d/``. In order to run
the cloud provider tests, valid credentials, which differ per provider, must be
supplied. Each credential item that must be supplied is indicated by an empty
string value and should be edited by the user before running the tests. For
example, DigitalOcean requires a client key and an api key to operate. Therefore,
the default cloud provider configuration file for DigitalOcean looks like this:

.. code-block:: yaml

    digitalocean-config:
      driver: digitalocean
      client_key: ''
      api_key: ''
      location: New York 1

As indicated by the empty string values, the ``client_key`` and the ``api_key``
must be provided:

.. code-block:: yaml

    digitalocean-config:
      driver: digitalocean
      client_key: wFGEwgregeqw3435gDger
      api_key: GDE43t43REGTrkilg43934t34qT43t4dgegerGEgg
      location: New York 1

.. note::

    When providing credential information in cloud provider configuration files,
    do not include the single quotes.

Once all of the valid credentials for the cloud provider have been supplied, the
cloud provider tests can be run by setting the ``--cloud-provider-tests`` flag:

.. code-block:: bash

    ./tests/runtests.py --cloud-provider-tests


Running The Tests In A Docker Container
---------------------------------------

The test suite can be executed under a `docker`_ container using the
``--docked`` option flag. The `docker`_ container must be properly configured
on the system invoking the tests and the container must have access to the
internet.

Here's a simple usage example:

.. code-block:: bash

    python tests/runtests.py --docked=ubuntu-12.04 -v

The full `docker`_ container repository can also be provided:

.. code-block:: bash

    python tests/runtests.py --docked=salttest/ubuntu-12.04 -v


The SaltStack team is creating some containers which will have the necessary
dependencies pre-installed. Running the test suite on a container allows
destructive tests to run without making changes to the main system. It also
enables the test suite to run under a different distribution than the one
the main system is currently using.

The current list of test suite images is on Salt's `docker repository`_.

Custom `docker`_ containers can be provided by submitting a pull request
against Salt's `docker Salt test containers`_ repository.

.. _`docker`: https://www.docker.io/
.. _`docker repository`: https://index.docker.io/u/salttest/
.. _`docker Salt test containers`: https://github.com/saltstack/docker-containers


Automated Test Runs
===================

SaltStack maintains a Jenkins server to allow for the execution of tests
across supported platforms. The tests executed from Salt's Jenkins server
create fresh virtual machines for each test run, then execute destructive
tests on the new, clean virtual machine.

SaltStack's Jenkins server continuously runs the entire test suite,
including destructive tests, on an array of various supported operating
systems throughout the day. Each actively supported branch of Salt's
repository runs the tests located in the respective branch's code. Each set
of branch tests also includes a pylint run. These branch tests help ensure
the viability of Salt code at any given point in time as pull requests
are merged into branches throughout the day.

In addition to branch tests, SaltStack's Jenkins server also runs tests
on pull requests. These pull request tests include a smaller set of
virtual machines that run on the branch tests. The pull request tests,
like the branch tests, include a pylint test as well.

When a pull request is submitted to Salt's repository on GitHub, the suite
of pull request tests are started by Jenkins. These tests are used to
gauge the pull request's viability to merge into Salt's codebase. If these
initial tests pass, the pull request can then merged into the Salt branch
by one of Salt's core developers, pending their discretion. If the initial
tests fail, core developers may request changes to the pull request. If the
failure is unrelated to the changes in question, core developers may merge
the pull request despite the initial failure.

As soon as the pull request is merged, the changes will be added to the
next branch test run on Jenkins.

For a full list of currently running test environments, go to
http://jenkins.saltstack.com.


Using Salt-Cloud on Jenkins
---------------------------

For testing Salt on Jenkins, SaltStack uses :ref:`Salt-Cloud<salt-cloud>` to
spin up virtual machines. The script using Salt-Cloud to accomplish this is
open source and can be found here: :blob:`tests/jenkins.py`


Writing Tests
=============

The salt testing infrastructure is divided into two classes of tests,
integration tests and unit tests. These terms may be defined differently in
other contexts, but for Salt they are defined this way:

- Unit Test: Tests which validate isolated code blocks and do not require
  external interfaces such as ``salt-call`` or any of the salt daemons.

- Integration Test: Tests which validate externally accessible features.

Salt testing uses unittest2 from the python standard library and MagicMock.

* :ref:`Writing integration tests <integration-tests>`
* :ref:`Writing unit tests <unit-tests>`


Naming Conventions
------------------

Any function in either integration test files or unit test files that is doing
the actual testing, such as functions containing assertions, must start with
``test_``:

.. code-block:: python

    def test_user_present(self):

When functions in test files are not prepended with ``test_``, the function
acts as a normal, helper function and is not run as a test by the test suite.


Submitting New Tests
--------------------

Which branch of the Salt codebase should new tests be written against? The location
of where new tests should be submitted depends largely on the reason you're writing
the tests.


Tests for New Features
~~~~~~~~~~~~~~~~~~~~~~

If you are adding new functionality to Salt, please write the tests for this new
feature in the same pull request as the new feature. New features should always be
submitted to the ``develop`` branch.

If you have already submitted the new feature, but did not write tests in the original
pull request that has already been merged, please feel free to submit a new pull
request containing tests. If the feature was recently added to Salt's ``develop``
branch, then the tests should be added there as well. However, if the feature was
added to ``develop`` some time ago and is already present in one or more release
branches, please refer to the `Tests for Entire Files or Functions`_ section below
for more details about where to submit tests for functions or files that do not
already have tests.


Tests to Accompany a Bugfix
~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you are writing tests for code that fixes a bug in Salt, please write the test
in the same pull request as the bugfix. If you're unsure of where to submit your
bugfix and accompanying test, please review the
:ref:`Which Salt Branch? <which-salt-branch>` documentation in Salt's
:ref:`Contributing <contributing>` guide.


Tests for Entire Files or Functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Sometimes entire files in Salt are completely untested. If you are writing tests for
a file that doesn't have any tests written for it, write your test against the
earliest supported release branch that contains the file or function you're testing.

Once your tests are submitted in a pull request and is merged into the branch in
question, the tests you wrote will be merged-forward by SaltStack core engineers and
the new tests will propagate to the newer release branches. That way the tests you
wrote will apply to all current and relevant release branches, and not just the ``develop``
branch, for example. This methodology will help protect against regressions on older
files in Salt's codebase.

There may be times when the tests you write against an older branch fail in the
merge-forward process because functionality has changed in newer release branches.
In these cases, a Salt core developer may reach out to you for advice on the tests in
question if the path forward is unclear.

.. note::

    If tests are written against a file in an older release branch and then merged forward,
    there may be new functionality in the file that is present in the new release branch
    that is untested.It would be wise to see if new functionality could use additional
    testing once the test file has propagated to newer release branches.


Test Helpers
------------

Several Salt-specific helpers are available. A full list is available by inspecting
functions exported in `tests.support.helpers`.

`@expensiveTest` -- Designates a test which typically requires a relatively costly
external resource, like a cloud virtual machine. This decorator is not normally
used by developers outside of the Salt core team.

`@destructiveTest` -- Marks a test as potentially destructive. It will not be run
by the test runner unless the ``-run-destructive`` test is expressly passed.

`@requires_network` -- Requires a network connection for the test to operate
successfully. If a network connection is not detected, the test will not run.

`@requires_salt_modules` -- Requires all the modules in a list of modules in
order for the test to be executed. Otherwise, the test is skipped.

`@requires_system_grains` -- Loads and passes the grains on the system as an
keyword argument to the test function with the name `grains`.

`@skip_if_binaries_missing(['list', 'of', 'binaries'])` -- If called from inside a test,
the test will be skipped if the binaries are not all present on the system.

`@skip_if_not_root` -- If the test is not executed as root, it will be skipped.

`@with_system_user` -- Creates and optionally destroys a system user within a test case.
See implementation details in `tests.support.helpers` for details.

`@with_system_group` -- Creates and optionally destroys a system group within a test case.
See implementation details in `tests.support.helpers` for details.

`@with_system_user_and_group` -- Creates and optionally destroys a system user and group
within a test case.  See implementation details in `tests.support.helpers` for details.