diff --git a/TESTING.rst b/TESTING.rst new file mode 100644 index 000000000..0d6814e8e --- /dev/null +++ b/TESTING.rst @@ -0,0 +1,180 @@ +Testing Neutron +============================================================= + +Overview +-------- + +The unit tests are meant to cover as much code as possible and should +be executed without the service running. They are designed to test +the various pieces of the neutron tree to make sure any new changes +don't break existing functionality. + +The functional tests are intended to validate actual system +interaction. Mocks should be used sparingly, if at all. Care +should be taken to ensure that existing system resources are not +modified and that resources created in tests are properly cleaned +up. + +Development process +------------------- + +It is expected that any new changes that are proposed for merge +come with tests for that feature or code area. Ideally any bugs +fixes that are submitted also have tests to prove that they stay +fixed! In addition, before proposing for merge, all of the +current tests should be passing. + +Virtual environments +~~~~~~~~~~~~~~~~~~~~ + +Testing OpenStack projects, including Neutron, is made easier with `DevStack `_. + +Create a machine (such as a VM or Vagrant box) running a distribution supported +by DevStack and install DevStack there. For example, there is a Vagrant script +for DevStack at https://github.com/bcwaldon/vagrant_devstack. + + .. note:: + + If you prefer not to use DevStack, you can still check out source code on your local + machine and develop from there. + + +Running unit tests +------------------ + +There are three mechanisms for running tests: run_tests.sh, tox, +and nose. Before submitting a patch for review you should always +ensure all test pass; a tox run is triggered by the jenkins gate +executed on gerrit for each patch pushed for review. + +With these mechanisms you can either run the tests in the standard +environment or create a virtual environment to run them in. + +By default after running all of the tests, any pep8 errors +found in the tree will be reported. + + +With `run_tests.sh` +~~~~~~~~~~~~~~~~~~~ + +You can use the `run_tests.sh` script in the root source directory to execute +tests in a virtualenv:: + + ./run_tests -V + + +With `nose` +~~~~~~~~~~~ + +You can use `nose`_ to run individual tests, as well as use for debugging +portions of your code:: + + source .venv/bin/activate + pip install nose + nosetests + +There are disadvantages to running Nose - the tests are run sequentially, so +race condition bugs will not be triggered, and the full test suite will +take significantly longer than tox & testr. The upside is that testr has +some rough edges when it comes to diagnosing errors and failures, and there is +no easy way to set a breakpoint in the Neutron code, and enter an +interactive debugging session while using testr. + +.. _nose: https://nose.readthedocs.org/en/latest/index.html + +With `tox` +~~~~~~~~~~ + +Neutron, like other OpenStack projects, uses `tox`_ for managing the virtual +environments for running test cases. It uses `Testr`_ for managing the running +of the test cases. + +Tox handles the creation of a series of `virtualenvs`_ that target specific +versions of Python (2.6, 2.7, 3.3, etc). + +Testr handles the parallel execution of series of test cases as well as +the tracking of long-running tests and other things. + +Running unit tests is as easy as executing this in the root directory of the +Neutron source code:: + + tox + +For more information on the standard Tox-based test infrastructure used by +OpenStack and how to do some common test/debugging procedures with Testr, +see this wiki page: + + https://wiki.openstack.org/wiki/Testr + +.. _Testr: https://wiki.openstack.org/wiki/Testr +.. _tox: http://tox.readthedocs.org/en/latest/ +.. _virtualenvs: https://pypi.python.org/pypi/virtualenv + + +Running individual tests +~~~~~~~~~~~~~~~~~~~~~~~~ + +For running individual test modules or cases, you just need to pass +the dot-separated path to the module you want as an argument to it. + +For executing a specific test case, specify the name of the test case +class separating it from the module path with a colon. + +For example, the following would run only the JSONV2TestCase tests from +neutron/tests/unit/test_api_v2.py:: + + $ ./run_tests.sh neutron.tests.unit.test_api_v2:JSONV2TestCase + +or:: + + $ ./tox neutron.tests.unit.test_api_v2:JSONV2TestCase + +Adding more tests +~~~~~~~~~~~~~~~~~ + +Neutron has a fast growing code base and there is plenty of areas that +need to be covered by unit and functional tests. + +To get a grasp of the areas where tests are needed, you can check +current coverage by running:: + + $ ./run_tests.sh -c + +Debugging +--------- + +By default, calls to pdb.set_trace() will be ignored when tests +are run. For pdb statements to work, invoke run_tests as follows:: + + $ ./run_tests.sh -d [test module path] + +It's possible to debug tests in a tox environment:: + + $ tox -e venv -- python -m testtools.run [test module path] + +Tox-created virtual environments (venv's) can also be activated +after a tox run and reused for debugging:: + + $ tox -e venv + $ . .tox/venv/bin/activate + $ python -m testtools.run [test module path] + +Tox packages and installs the neutron source tree in a given venv +on every invocation, but if modifications need to be made between +invocation (e.g. adding more pdb statements), it is recommended +that the source tree be installed in the venv in editable mode:: + + # run this only after activating the venv + $ pip install --editable . + +Editable mode ensures that changes made to the source tree are +automatically reflected in the venv, and that such changes are not +overwritten during the next tox run. + +Post-mortem debugging +~~~~~~~~~~~~~~~~~~~~~ + +Setting OS_POST_MORTEM_DEBUG=1 in the shell environment will ensure +that pdb.post_mortem() will be invoked on test failure:: + + $ OS_POST_MORTEM_DEBUG=1 ./run_tests.sh -d [test module path]