.. _writing_tests: Writing Avocado Tests with Python ================================= We are going to write an Avocado test in Python and we are going to inherit from :class:`avocado.Test`. This makes this test a so-called instrumented test. Basic example ------------- Let's re-create an old time favorite, ``sleeptest`` [#f1]_. It is so simple, it does nothing besides sleeping for a while:: import time from avocado import Test class SleepTest(Test): def test(self): sleep_length = self.params.get('sleep_length', default=1) self.log.debug("Sleeping for %.2f seconds", sleep_length) time.sleep(sleep_length) This is about the simplest test you can write for Avocado, while still leveraging its API power. As can be seen in the example above, an Avocado test is a method that starts with ``test`` in a class that inherits from :mod:`avocado.Test`. .. note:: Avocado also supports coroutines as tests. Simply declare your test method using the ``async def`` syntax, and Avocado will run it inside an asyncio loop. Multiple tests and naming conventions ------------------------------------- You can have multiple tests in a single class. To do so, just give the methods names that start with ``test``, say ``test_foo``, ``test_bar`` and so on. We recommend you follow this naming style, as defined in the `PEP8 Function Names`_ section. For the class name, you can pick any name you like, but we also recommend that it follows the CamelCase convention, also known as CapWords, defined in the PEP 8 document under `Class Names`_. Convenience Attributes ---------------------- Note that the test class provides you with a number of convenience attributes: * A ready to use log mechanism for your test, that can be accessed by means of ``self.log``. It lets you log debug, info, error and warning messages. * A parameter passing system (and fetching system) that can be accessed by means of ``self.params``. This is hooked to the Varianter, about which you can find that more information at :ref:`test-parameter`. * And many more (see :mod:`avocado.core.test.Test`) To minimize the accidental clashes we define the public ones as properties so if you see something like ``AttributeError: can't set attribute`` double check you are not overriding these. .. _Test statuses: Test statuses ------------- Avocado supports the most common exit statuses: * ``PASS`` - test passed, there were no untreated exceptions * ``WARN`` - a variant of ``PASS`` that keeps track of noteworthy events that ultimately do not affect the test outcome. An example could be ``soft lockup`` present in the ``dmesg`` output. It's not related to the test results and unless there are failures in the test it means the feature probably works as expected, but there were certain condition which might be nice to review. (some result plugins does not support this and report ``PASS`` instead) * ``SKIP`` - the test's pre-requisites were not satisfied and the test's body was not executed (nor its ``setUp()`` and ``tearDown``). * ``CANCEL`` - the test was canceled somewhere during the ``setUp()``, the test method or the ``tearDown()``. The ``setUp()`` and ``tearDown`` methods are executed. * ``FAIL`` - test did not result in the expected outcome. A failure points at a (possible) bug in the tested subject, and not in the test itself. When the test (and its) execution breaks, an ``ERROR`` and not a ``FAIL`` is reported." * ``ERROR`` - this points (probably) at a bug in the test itself, and not in the subject being tested.It is usually caused by uncaught exception and such failures needs to be thoroughly explored and should lead to test modification to avoid this failure or to use ``self.fail`` along with description how the subject under testing failed to perform it's task. * ``INTERRUPTED`` - this result can't be set by the test writer, it is only possible when the timeout is reached or when the user hits ``CTRL+C`` while executing this test. * other - there are some other internal test statuses, but you should not ever face them. As you can see the ``FAIL`` is a neat status, if tests are developed correctly. When writing tests always think about what its ``setUp`` should be, what the ``test body`` and is expected to go wrong in the test. To support you Avocado supports several methods: Test methods ------------ The simplest way to set the status is to use ``self.fail``, ``self.error`` or ``self.cancel`` directly from test. To remember a warning, one simply writes to ``self.log.warning`` logger. This won't interrupt the test execution, but it will remember the condition and, if there are no failures, will report the test as ``WARN``. Turning errors into failures ---------------------------- Errors on Python code are commonly signaled in the form of exceptions being thrown. When Avocado runs a test, any unhandled exception will be seen as a test ``ERROR``, and not as a ``FAIL``. Still, it's common to rely on libraries, which usually raise custom (or builtin) exceptions. Those exceptions would normally result in ``ERROR`` but if you are certain this is an odd behavior of the object under testing, you should catch the exception and explain the failure in ``self.fail`` method:: try: process.run("stress_my_feature") except process.CmdError as details: self.fail("The stress command failed: %s" % details) If your test compounds of many executions and you can't get this exception in other case then expected failure, you can simplify the code by using ``fail_on`` decorator:: @avocado.fail_on(process.CmdError) def test(self): process.run("first cmd") process.run("second cmd") process.run("third cmd") Once again, keeping your tests up-to-date and distinguishing between ``FAIL`` and ``ERROR`` will save you a lot of time while reviewing the test results. .. _turning_errors_into_cancels: Turning errors into cancels --------------------------- It is also possible to assume unhandled exception to be as a test ``CANCEL`` instead of a test ``ERROR`` simply by using ``cancel_on`` decorator:: def test(self): @avocado.cancel_on(TypeError) def foo(): raise TypeError foo() .. _saving-test-generated-custom-data: Saving test generated (custom) data ----------------------------------- Each test instance provides a so called ``whiteboard``. It can be accessed through ``self.whiteboard``. This whiteboard is simply a string that will be automatically saved to test results after the test finishes (it's not synced during the execution so when the machine or Python crashes badly it might not be present and one should use direct io to the ``outputdir`` for critical data). If you choose to save binary data to the whiteboard, it's your responsibility to encode it first (base64 is the obvious choice). Building on the previously demonstrated ``sleeptest``, suppose that you want to save the sleep length to be used by some other script or data analysis tool:: def test(self): sleep_length = self.params.get('sleep_length', default=1) self.log.debug("Sleeping for %.2f seconds", sleep_length) time.sleep(sleep_length) self.whiteboard = "%.2f" % sleep_length The whiteboard can and should be exposed by files generated by the available test result plugins. The ``results.json`` file already includes the whiteboard for each test. Additionally, we'll save a raw copy of the whiteboard contents on a file ``$RESULTS/test-results/$TEST_ID/whiteboard``, for your convenience (maybe you want to use the result of a benchmark directly with your custom made scripts to analyze that particular benchmark result). If you need to attach several output files, you can also use ``self.outputdir``, which points to the ``$RESULTS/test-results/$TEST_ID/data`` location and is reserved for arbitrary test result data. .. _accessing-test-data-files: Accessing test data files ------------------------- Some tests can depend on data files, external to the test file itself. Avocado provides a test API that makes it really easy to access such files: :meth:`get_data() `. For Avocado tests (that is, ``avocado-instrumented`` tests) :meth:`get_data() ` allows test data files to be accessed from up to three sources: * **file** level data directory: a directory named after the test file, but ending with ``.data``. For a test file ``/home/user/test.py``, the file level data directory is ``/home/user/test.py.data/``. * **test** level data directory: a directory named after the test file and the specific test name. These are useful when different tests part of the same file need different data files (with the same name or not). Considering the previous example of ``/home/user/test.py``, and supposing it contains two tests, ``MyTest.test_foo`` and ``MyTest.test_bar``, the test level data directories will be, ``/home/user/test.py.data/MyTest.test_foo/`` and ``home/user/test.py.data/MyTest.test_bar/`` respectively. * **variant** level data directory: if variants are being used during the test execution, a directory named after the variant will also be considered when looking for test data files. For test file ``/home/user/test.py``, and test ``MyTest.test_foo``, with variant ``debug-ffff``, the data directory path will be ``/home/user/test.py.data/MyTest.test_foo/debug-ffff/``. .. note:: Unlike avocado-instrumented tests, exec-tests only define ``file`` and ``variant`` data_dirs, therefore the most-specific data-dir might look like ``/bin/echo.data/debug-ffff/``. Avocado looks for data files in the order defined at :attr:`DATA_SOURCES `, which are from most specific one, to most generic one. That means that, if a variant is being used, the **variant** directory is used first. Then the **test** level directory is attempted, and finally the **file** level directory. Additionally you can use ``get_data(filename, must_exist=False)`` to get expected location of a possibly non-existing file, which is useful when you intend to create it. .. tip:: When running tests you can use the ``--log-test-data-directories`` command line option log the test data directories that will be used for that specific test and execution conditions (such as with or without variants). Look for "Test data directories" in the test logs. .. note:: The previously existing API ``avocado.core.test.Test.datadir``, used to allow access to the data directory based on the test file location only. This API has been removed. If, for whatever reason you still need to access the data directory based on the test file location only, you can use ``get_data(filename='', source='file', must_exist=False)`` instead. .. _accessing-test-parameter: Accessing test parameters ------------------------- Each test has a set of parameters that can be accessed through ``self.params.get($name, $path=None, $default=None)`` where: * name - name of the parameter (key) * path - where to look for this parameter (when not specified uses mux-path) * default - what to return when param not found The path is a bit tricky. Avocado uses tree to represent parameters. In simple scenarios you don't need to worry and you'll find all your values in default path, but eventually you might want to check-out :ref:`test-parameter` to understand the details. Let's say your test receives following params (you'll learn how to execute them in the following section):: $ avocado variants -m examples/tests/sleeptenmin.py.data/sleeptenmin.yaml --variants 2 ... Variant 1: /run/sleeptenmin/builtin, /run/variants/one_cycle /run/sleeptenmin/builtin:sleep_method => builtin /run/variants/one_cycle:sleep_cycles => 1 /run/variants/one_cycle:sleep_length => 600 ... In test you can access those params by: .. code-block:: python self.params.get("sleep_method") # returns "builtin" self.params.get("sleep_cycles", '*', 10) # returns 1 self.params.get("sleep_length", "/*/variants/*" # returns 600 .. note:: The path is important in complex scenarios where clashes might occur, because when there are multiple values with the same key matching the query Avocado raises an exception. As mentioned you can avoid those by using specific paths or by defining custom mux-path which allows specifying resolving hierarchy. More details can be found in :ref:`test-parameter`. Running multiple variants of tests ---------------------------------- In the previous section we described how parameters are handled. Now, let's have a look at how to produce them and execute your tests with different parameters. The variants subsystem is what allows the creation of multiple variations of parameters, and the execution of tests with those parameter variations. This subsystem is pluggable, so you might use custom plugins to produce variants. To keep things simple, let's use Avocado's primary implementation, called "yaml_to_mux". The "yaml_to_mux" plugin accepts YAML files. Those will create a tree-like structure, store the variables as parameters and use custom tags to mark locations as "multiplex" domains. Let's use ``examples/tests/sleeptenmin.py.data/sleeptenmin.yaml`` file as an example: .. code-block:: yaml sleeptenmin: !mux builtin: sleep_method: builtin shell: sleep_method: shell variants: !mux one_cycle: sleep_cycles: 1 sleep_length: 600 six_cycles: sleep_cycles: 6 sleep_length: 100 one_hundred_cycles: sleep_cycles: 100 sleep_length: 6 six_hundred_cycles: sleep_cycles: 600 sleep_length: 1 Which produces following structure and parameters:: $ avocado variants -m examples/tests/sleeptenmin.py.data/sleeptenmin.yaml --summary 2 --variants 2 Multiplex tree representation: ┗━━ run ┣━━ sleeptenmin ┃ ╠══ builtin ┃ ║ → sleep_method: builtin ┃ ╚══ shell ┃ → sleep_method: shell ┗━━ variants ╠══ one_cycle ║ → sleep_length: 600 ║ → sleep_cycles: 1 ╠══ six_cycles ║ → sleep_length: 100 ║ → sleep_cycles: 6 ╠══ one_hundred_cycles ║ → sleep_length: 6 ║ → sleep_cycles: 100 ╚══ six_hundred_cycles → sleep_length: 1 → sleep_cycles: 600 Multiplex variants (8): Variant builtin-one_cycle-f659: /run/sleeptenmin/builtin, /run/variants/one_cycle /run/sleeptenmin/builtin:sleep_method => builtin /run/variants/one_cycle:sleep_cycles => 1 /run/variants/one_cycle:sleep_length => 600 Variant builtin-six_cycles-723b: /run/sleeptenmin/builtin, /run/variants/six_cycles /run/sleeptenmin/builtin:sleep_method => builtin /run/variants/six_cycles:sleep_cycles => 6 /run/variants/six_cycles:sleep_length => 100 Variant builtin-one_hundred_cycles-633a: /run/sleeptenmin/builtin, /run/variants/one_hundred_cycles /run/sleeptenmin/builtin:sleep_method => builtin /run/variants/one_hundred_cycles:sleep_cycles => 100 /run/variants/one_hundred_cycles:sleep_length => 6 Variant builtin-six_hundred_cycles-a570: /run/sleeptenmin/builtin, /run/variants/six_hundred_cycles /run/sleeptenmin/builtin:sleep_method => builtin /run/variants/six_hundred_cycles:sleep_cycles => 600 /run/variants/six_hundred_cycles:sleep_length => 1 Variant shell-one_cycle-55f5: /run/sleeptenmin/shell, /run/variants/one_cycle /run/sleeptenmin/shell:sleep_method => shell /run/variants/one_cycle:sleep_cycles => 1 /run/variants/one_cycle:sleep_length => 600 Variant shell-six_cycles-9e23: /run/sleeptenmin/shell, /run/variants/six_cycles /run/sleeptenmin/shell:sleep_method => shell /run/variants/six_cycles:sleep_cycles => 6 /run/variants/six_cycles:sleep_length => 100 Variant shell-one_hundred_cycles-586f: /run/sleeptenmin/shell, /run/variants/one_hundred_cycles /run/sleeptenmin/shell:sleep_method => shell /run/variants/one_hundred_cycles:sleep_cycles => 100 /run/variants/one_hundred_cycles:sleep_length => 6 Variant shell-six_hundred_cycles-1e84: /run/sleeptenmin/shell, /run/variants/six_hundred_cycles /run/sleeptenmin/shell:sleep_method => shell /run/variants/six_hundred_cycles:sleep_cycles => 600 /run/variants/six_hundred_cycles:sleep_length => 1 You can see that it creates all possible variants of each ``multiplex domain``, which are defined by ``!mux`` tag in the YAML file and displayed as single lines in tree view (compare to double lines which are individual nodes with values). In total it'll produce 8 variants of each test:: $ avocado run --mux-yaml examples/tests/sleeptenmin.py.data/sleeptenmin.yaml -- examples/tests/passtest.py JOB ID : cc7ef22654c683b73174af6f97bc385da5a0f02f JOB LOG : $HOME/avocado/job-results/job-2017-01-22T11.26-cc7ef22/job.log (1/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-one_cycle-0aae: STARTED (1/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-one_cycle-0aae: PASS (0.01 s) (2/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-six_cycles-ca95: STARTED (2/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-six_cycles-ca95: PASS (0.01 s) (3/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-one_hundred_cycles-e897: STARTED (3/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-one_hundred_cycles-e897: PASS (0.01 s) (4/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-six_hundred_cycles-b0b0: STARTED (4/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-builtin-variants-six_hundred_cycles-b0b0: PASS (0.01 s) (5/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-one_cycle-f35d: STARTED (5/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-one_cycle-f35d: PASS (0.01 s) (6/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-six_cycles-56b6: STARTED (6/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-six_cycles-56b6: PASS (0.01 s) (7/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-one_hundred_cycles-ec04: STARTED (7/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-one_hundred_cycles-ec04: PASS (0.01 s) (8/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-six_hundred_cycles-8fff: STARTED (8/8) examples/tests/passtest.py:PassTest.test;run-sleeptenmin-shell-variants-six_hundred_cycles-8fff: PASS (0.01 s) RESULTS : PASS 8 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 JOB TIME : 0.16 s There are other options to influence the params so please check out ``avocado run -h`` and for details use :ref:`test-parameter`. :class:`unittest.TestCase` heritage ----------------------------------- Since an Avocado test inherits from :class:`unittest.TestCase`, you can use all the assertion methods that its parent. The code example below uses :meth:`assertEqual `, :meth:`assertTrue ` and :meth:`assertIsInstace `:: from avocado import Test class RandomExamples(Test): def test(self): self.log.debug("Verifying some random math...") four = 2 * 2 four_ = 2 + 2 self.assertEqual(four, four_, "something is very wrong here!") self.log.debug("Verifying if a variable is set to True...") variable = True self.assertTrue(variable) self.log.debug("Verifying if this test is an instance of test.Test") self.assertIsInstance(self, Test) Running tests under other :mod:`unittest` runners ------------------------------------------------- `nose `__ is another Python testing framework that is also compatible with :mod:`unittest`. Because of that, you can run Avocado tests with the ``nosetests`` application:: $ nosetests examples/tests/sleeptest.py . ---------------------------------------------------------------------- Ran 1 test in 1.004s OK Conversely, you can also use the standard :func:`unittest.main` entry point to run an Avocado test. Check out the following code, to be saved as ``dummy.py``:: from avocado import Test from unittest import main class Dummy(Test): def test(self): self.assertTrue(True) if __name__ == '__main__': main() It can be run by:: $ python dummy.py . ---------------------------------------------------------------------- Ran 1 test in 0.000s OK But we'd still recommend using ``avocado.main`` instead which is our main entry point. .. _Setup and cleanup methods: Setup and cleanup methods ------------------------- To perform setup actions before/after your test, you may use ``setUp`` and ``tearDown`` methods. The ``tearDown`` method is always executed even on ``setUp`` failure so don't forget to initialize your variables early in the ``setUp``. Example of usage is in the next section `Running third party test suites`_. Running third party test suites ------------------------------- It is very common in test automation workloads to use test suites developed by third parties. By wrapping the execution code inside an Avocado test module, you gain access to the facilities and API provided by the framework. Let's say you want to pick up a test suite written in C that it is in a tarball, uncompress it, compile the suite code, and then executing the test. Here's an example that does that:: #!/usr/bin/env python3 import os from avocado import Test from avocado.utils import archive, build, process class SyncTest(Test): """ Execute the synctest test suite. :param sync_tarball: path to the tarball relative to a data directory :param default_symbols: whether to build with debug symbols (bool) :param sync_length: how many data should by used in sync test :param sync_loop: how many writes should be executed in sync test """ def setUp(self): """ Build the synctest suite. """ self.cwd = os.getcwd() sync_tarball = self.params.get('sync_tarball', '*', 'synctest.tar.bz2') tarball_path = self.get_data(sync_tarball) if tarball_path is None: self.cancel('Test is missing data file %s' % tarball_path) archive.extract(tarball_path, self.workdir) srcdir = os.path.join(self.workdir, 'synctest') os.chdir(srcdir) if self.params.get('debug_symbols', default=True): build.make(srcdir, env={'CFLAGS': '-g -O0'}, extra_args='synctest') else: build.make(srcdir) def test(self): """ Execute synctest with the appropriate params. """ path = os.path.join(os.getcwd(), 'synctest') cmd = ('%s %s %s' % (path, self.params.get('sync_length', default=100), self.params.get('sync_loop', default=10))) process.system(cmd) os.chdir(self.cwd) Here we have an example of the ``setUp`` method in action: Here we get the location of the test suite code (tarball) through :func:`avocado.Test.get_data`, then uncompress the tarball through :func:`avocado.utils.archive.extract`, an API that will decompress the suite tarball, followed by :func:`avocado.utils.build.make`, that will build the suite. In this example, the ``test`` method just gets into the base directory of the compiled suite and executes the ``./synctest`` command, with appropriate parameters, using :func:`avocado.utils.process.system`. .. _Fetching asset files: Fetching asset files -------------------- To run third party test suites as mentioned above, or for any other purpose, we offer an asset fetcher as a method of Avocado Test class. The asset fetch method looks for a list of directories in the ``cache_dirs`` key, inside the ``[datadir.paths]`` section from the configuration files. Read-only directories are also supported. When the asset file is not present in any of the provided directories, Avocado will try to download the file from the provided locations, copying it to the first writable cache directory. Example:: cache_dirs = ['/usr/local/src/', '~/avocado/data/cache'] In the example above, ``/usr/local/src/`` is a read-only directory. In that case, when Avocado needs to fetch the asset from the locations, the asset will be copied to the ``~/avocado/data/cache`` directory. If the tester does not provide a ``cache_dirs`` for the test execution, Avocado creates a ``cache`` directory inside the Avocado ``data_dir`` location to put the fetched files in. * Use case 1: no ``cache_dirs`` key in config files, only the asset name provided in the full URL format:: ... def setUp(self): stress = 'https://fossies.org/linux/privat/stress-1.0.4.tar.gz' tarball = self.fetch_asset(stress) archive.extract(tarball, self.workdir) ... In this case, ``fetch_asset()`` will download the file from the URL provided, copying it to the ``$data_dir/cache`` directory. The ``fetch_asset()`` method returns the target location of the fetched asset. In this example, the ``tarball`` variable holds ``/home/user/avocado/data/cache/stress-1.0.4.tar.gz``. * Use case 2: Read-only cache directory provided. ``cache_dirs = ['/mnt/files']``:: ... def setUp(self): stress = 'https://fossies.org/linux/privat/stress-1.0.4.tar.gz' tarball = self.fetch_asset(stress) archive.extract(tarball, self.workdir) ... In this case, Avocado tries to find ``stress-1.0.4.tar.gz`` file in ``/mnt/files`` directory. If it's not found, since ``/mnt/files`` cache is read-only, Avocado tries to download the asset file to the ``$data_dir/cache`` directory. * Use case 3: Writable cache directory provided, along with a list of locations. Use of the default cache directory, ``cache_dirs = ['~/avocado/data/cache']``:: ... def setUp(self): st_name = 'stress-1.0.4.tar.gz' st_hash = 'e1533bc704928ba6e26a362452e6db8fd58b1f0b' st_loc = ['https://fossies.org/linux/privat/stress-1.0.4.tar.gz', 'ftp://foo.bar/stress-1.0.4.tar.gz'] tarball = self.fetch_asset(st_name, asset_hash=st_hash, locations=st_loc) archive.extract(tarball, self.workdir) ... In this case, Avocado tries to download ``stress-1.0.4.tar.gz`` from the provided locations list (if it's not already in the default cache, ``~/avocado/data/cache``). As the hash was also provided, Avocado verifies the hash. To do so, Avocado first looks for a hash file named ``stress-1.0.4.tar.gz.CHECKSUM`` in the same directory. If the hash file is not available, Avocado computes the hash and creates the hash file for later use. The resulting ``tarball`` variable content will be ``~/avocado/cache/stress-1.0.4.tar.gz``. An exception is raised if Avocado fails to download or to verify the file. * Use case 4: Low bandwidth available for download of a large file which takes a lot of time to download and causes a CI, like Travis, for example, to timeout the test execution. Do not cancel the test if the file is not available:: ... def setUp(self): st_name = 'stress-1.0.4.tar.gz' st_hash = 'e1533bc704928ba6e26a362452e6db8fd58b1f0b' st_loc = ['https://fossies.org/linux/privat/stress-1.0.4.tar.gz', 'ftp://foo.bar/stress-1.0.4.tar.gz'] tarball = self.fetch_asset(st_name, asset_hash=st_hash, locations=st_loc, find_only=True) archive.extract(tarball, self.workdir) ... Setting the ``find_only`` parameter to ``True`` will make Avocado look for the asset in the cache, but will not attempt to download it if the asset is not available. The asset download can be done prior to the test execution using the command-line ``avocado assets fetch avocado-instrumented``. In this example, if the asset is not available in the cache, the test will continue to run and when the test tries to use the asset, it will fail. A solution for that is presented in the next use case. * Use case 5: Low bandwidth available for download or a large file which takes a lot of time to download and causes a CI, like Travis, for example, to timeout the test execution. Cancel the test if the file is not available:: ... def setUp(self): st_name = 'stress-1.0.4.tar.gz' st_hash = 'e1533bc704928ba6e26a362452e6db8fd58b1f0b' st_loc = ['https://fossies.org/linux/privat/stress-1.0.4.tar.gz', 'ftp://foo.bar/stress-1.0.4.tar.gz'] tarball = self.fetch_asset(st_name, asset_hash=st_hash, locations=st_loc, find_only=True, cancel_on_missing=True) archive.extract(tarball, self.workdir) ... With ``cancel_on_missing`` set to ``True`` and ``find_only`` set to ``True``, if the file is not available in the cache, the test is canceled. Detailing the ``fetch_asset()`` parameters: * ``name:`` The destination name used to the fetched file. It can also contains a full URI. The URI will be used as the location (after searching into the cache directories). * ``asset_hash:`` (optional) The expected hash for the file. If missing, Avocado skips the hash check. If provided, before computing the hash, Avocado looks for a hash file to verify the asset. If the hash file is not available, Avocado computes the hash and creates the hash file in the same cache directory for later use. * ``algorithm:`` (optional) Provided hash algorithm format. Defaults to sha1. * ``locations:`` (optional) List of locations used to try to fetch the file. The supported schemes are ``http://``, ``https://``, ``ftp://`` and ``file://``. The tester should inform the full url to the file, including the file name. The first fetch success skips the next locations. Notice that for ``file://`` Avocado creates a symbolic link in the cache directory, pointing to the original location of the file. * ``expire:`` (optional) period while a cached file is considered valid. After that period, the file will be downloaded again. The value can be an integer or a string containing the time and the unit. Example: '10d' (ten days). Valid units are ``s`` (second), ``m`` (minute), ``h`` (hour) and ``d`` (day). * ``find_only:`` (optional) tries to find the asset in the cache. If the asset file is not available in the cache, Avocado will not attempt to download it. * ``cancel_on_missing`` (optional) if set to ``True``, cancel the current running test if there is a problem while downloading the asset or if ``find_only=True`` and the asset is not available in the cache. The expected ``return`` of the method is the asset file path or an exception. Test log, stdout and stderr in native Avocado modules ----------------------------------------------------- If needed, you can write directly to the expected stdout and stderr files from the native test scope. It is important to make the distinction between the following entities: * The test logs * The test expected stdout * The test expected stderr The first one is used for debugging and informational purposes. Additionally writing to `self.log.warning` causes test to be marked as dirty and when everything else goes well the test ends with WARN. This means that the test passed but there were non-related unexpected situations described in warning log. You may log something into the test logs using the methods in :mod:`avocado.Test.log` class attributes. Consider the example:: class OutputTest(Test): def test(self): self.log.info("This goes to the log and it is only informational") self.log.warn("Oh, something unexpected, non-critical happened, " "but we can continue.") self.log.error("Describe the error here and don't forget to raise " "an exception yourself. Writing to self.log.error " "won't do that for you.") self.log.debug("Everybody look, I had a good lunch today...") If you need to write directly to the test stdout and stderr streams, Avocado makes two preconfigured loggers available for that purpose, named ``avocado.test.stdout`` and ``avocado.test.stderr``. You can use Python's standard logging API to write to them. Example:: import logging from avocado import Test class OutputTest(Test): def test(self): stdout = logging.getLogger('avocado.test.stdout') stdout.info('Informational line that will go to stdout') ... stderr = logging.getLogger('avocado.test.stderr') stderr.info('Informational line that will go to stderr') Avocado will automatically save anything a test generates on STDOUT into a ``stdout`` file, to be found at the test results directory. The same applies to anything a test generates on STDERR, that is, it will be saved into a ``stderr`` file at the same location. Setting a Test Timeout ---------------------- Sometimes your test suite/test might get stuck forever, and this might impact your test grid. You can account for that possibility and set up a ``timeout`` parameter for your test. The test timeout can be set through the test parameters, as shown below. :: sleep_length: 5 timeout: 3 :: $ avocado run examples/tests/sleeptest.py --mux-yaml /tmp/sleeptest-example.yaml JOB ID : c78464bde9072a0b5601157989a99f0ba32a288e JOB LOG : $HOME/avocado/job-results/job-2016-11-02T11.13-c78464b/job.log (1/1) examples/tests/sleeptest.py:SleepTest.test;run-0fc1: STARTED (1/1) examples/tests/sleeptest.py:SleepTest.test;run-0fc1: INTERRUPTED: timeout (3.01 s) RESULTS : PASS 0 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 1 JOB TIME : 3.14 s JOB HTML : $HOME/avocado/job-results/job-2016-11-02T11.13-c78464b/html/results.html :: $ cat $HOME/avocado/job-results/job-2016-11-02T11.13-c78464b/job.log 2021-10-01 15:44:53,622 job L0319 INFO | Multiplex tree representation: 2021-10-01 15:44:53,622 job L0319 INFO | \-- run 2021-10-01 15:44:53,622 job L0319 INFO | 2021-10-01 15:44:53,622 job L0319 INFO | Multiplex variants (1): 2021-10-01 15:44:53,622 job L0319 INFO | Variant run-0fc1: /run 2021-10-01 15:44:53,622 job L0312 INFO | Temporary dir: /tmp/avocado_tmp_hp4cswyn/avocado_job_pmn___6i 2021-10-01 15:44:53,622 job L0313 INFO | 2021-10-01 15:44:53,622 job L0306 INFO | Job ID: 927fdc4143e9e093a485319820825faacc0f36a3 2021-10-01 15:44:53,622 job L0309 INFO | 2021-10-01 15:44:54,165 selector_events L0059 DEBUG| Using selector: EpollSelector 2021-10-01 15:44:54,622 testlogs L0094 INFO | examples/tests/sleeptest.py:SleepTest.test;run-0fc1: STARTED 2021-10-01 15:44:57,653 testlogs L0101 INFO | examples/tests/sleeptest.py:SleepTest.test;run-0fc1: INTERRUPTED 2021-10-01 15:44:57,654 testlogs L0103 INFO | More information in /home/jarichte/avocado/job-results/job-2021-10-01T15.44-927fdc4/test-results/1-examples_tests_sleeptest.py_SleepTest.test_run-0fc1 2021-10-01 15:44:57,762 job L0643 INFO | Test results available in /home/jarichte/avocado/job-results/job-2021-10-01T15.44-927fdc4 The YAML file defines a test parameter ``timeout`` which overrides the default test timeout. When the timeout is reached, the spawner will terminate the test runner task, making it raise a :class:`avocado.core.exceptions.TestInterruptedError`. The termination process is specific to spawner implementation, for more information see :class:`avocado.core.plugin_interfaces.Spawner.terminate_task`. Skipping Tests -------------- To skip tests is in Avocado, you must use one of the Avocado skip decorators: - :func:`avocado.skip`: Skips a test. - :func:`avocado.skipIf`: Skips a test if the condition is ``True``. - :func:`avocado.skipUnless`: Skips a test if the condition is ``False`` Those decorators can be used with classes and both ``setUp()`` method and/or and in the ``test*()`` methods. The test below:: import avocado class MyTest(avocado.Test): @avocado.skipIf(1 == 1, 'Skipping on True condition.') def test1(self): pass @avocado.skip("Don't want this test now.") def test2(self): pass @avocado.skipUnless(1 == 1, 'Skipping on False condition.') def test3(self): pass Will produce the following result:: $ avocado run test_skip_decorators.py JOB ID : 59c815f6a42269daeaf1e5b93e52269fb8a78119 JOB LOG : $HOME/avocado/job-results/job-2017-02-03T17.41-59c815f/job.log (1/3) /tmp/test_skip_decorators.py:MyTest.test1: STARTED (1/3) /tmp/test_skip_decorators.py:MyTest.test1: SKIP: Skipping on True condition. (2/3) /tmp/test_skip_decorators.py:MyTest.test2: STARTED (2/3) /tmp/test_skip_decorators.py:MyTest.test2: SKIP: Don't want this test now. (3/3) /tmp/test_skip_decorators.py:MyTest.test3: STARTED (3/3) /tmp/test_skip_decorators.py:MyTest.test3: PASS (0.01 s) RESULTS : PASS 1 | ERROR 0 | FAIL 0 | SKIP 2 | WARN 0 | INTERRUPT 0 JOB TIME : 0.13 s JOB HTML : $HOME/avocado/job-results/job-2017-02-03T17.41-59c815f/html/results.html Notice the ``test3`` was not skipped because the provided condition was not ``False``. Using the skip decorators, nothing is actually executed. We will skip the ``setUp()`` method, the test method and the ``tearDown()`` method. .. note:: It's an erroneous condition, reported with test status ``ERROR``, to use any of the skip decorators on the ``tearDown()`` method. .. _skip-advanced-conditionals: Advanced Conditionals ~~~~~~~~~~~~~~~~~~~~~ More advanced use cases may require to evaluate the condition for skipping tests later, and may also need to introspect into the class that contains the test method in question. It's possible to achieve both by supplying a callable to the condition parameters instead. The following example does just that: .. literalinclude:: ../../../../../examples/tests/skip_conditional.py Even though the conditions for skipping tests are defined in the ``BaseTest`` class, the conditions will be evaluated when the tests are actually checked for execution, in the ``BareMetal`` and ``NonBareMetal`` classes. The result of running that test is:: JOB ID : 77d636c93ed3b5e6fef9c7b6c8d9fe0c84af1518 JOB LOG : $HOME/avocado/job-results/job-2021-03-17T20.10-77d636c/job.log (01/10) examples/tests/skip_conditional.py:BareMetal.test_specific: STARTED (01/10) examples/tests/skip_conditional.py:BareMetal.test_specific: PASS (0.01 s) (02/10) examples/tests/skip_conditional.py:BareMetal.test_bare_metal: STARTED (02/10) examples/tests/skip_conditional.py:BareMetal.test_bare_metal: PASS (0.01 s) (03/10) examples/tests/skip_conditional.py:BareMetal.test_large_memory: STARTED (03/10) examples/tests/skip_conditional.py:BareMetal.test_large_memory: SKIP: Not enough memory for test (04/10) examples/tests/skip_conditional.py:BareMetal.test_nested_virtualization: STARTED (04/10) examples/tests/skip_conditional.py:BareMetal.test_nested_virtualization: SKIP: Virtual Machine environment is required (05/10) examples/tests/skip_conditional.py:BareMetal.test_container: STARTED (05/10) examples/tests/skip_conditional.py:BareMetal.test_container: SKIP: Container environment is required (06/10) examples/tests/skip_conditional.py:NonBareMetal.test_specific: STARTED (06/10) examples/tests/skip_conditional.py:NonBareMetal.test_specific: PASS (0.01 s) (07/10) examples/tests/skip_conditional.py:NonBareMetal.test_bare_metal: STARTED (07/10) examples/tests/skip_conditional.py:NonBareMetal.test_bare_metal: SKIP: Bare metal environment is required (08/10) examples/tests/skip_conditional.py:NonBareMetal.test_large_memory: STARTED (08/10) examples/tests/skip_conditional.py:NonBareMetal.test_large_memory: SKIP: Not enough memory for test (09/10) examples/tests/skip_conditional.py:NonBareMetal.test_nested_virtualization: STARTED (09/10) examples/tests/skip_conditional.py:NonBareMetal.test_nested_virtualization: PASS (0.01 s) (10/10) examples/tests/skip_conditional.py:NonBareMetal.test_container: STARTED (10/10) examples/tests/skip_conditional.py:NonBareMetal.test_container: PASS (0.01 s) RESULTS : PASS 5 | ERROR 0 | FAIL 0 | SKIP 5 | WARN 0 | INTERRUPT 0 | CANCEL 0 JOB HTML : $HOME/avocado/job-results/job-2021-03-17T20.10-77d636c/results.html JOB TIME : 0.82 s Canceling Tests ---------------- You can cancel a test calling `self.cancel()` at any phase of the test (`setUp()`, test method or `tearDown()`). Test will finish with `CANCEL` status and will not make the Job to exit with a non-0 status. Example: .. literalinclude:: ../../../../../examples/tests/cancel_test.py In a system missing the `iperf` package but with `gcc` installed in the correct version, the result will be:: $ avocado run examples/tests/cancel_test.py JOB ID : 39c1f120830b9769b42f5f70b6b7bad0b1b1f09f JOB LOG : $HOME/avocado/job-results/job-2017-03-10T16.22-39c1f12/job.log (1/2) /tmp/cancel_test.py:CancelTest.test_iperf: STARTED (1/2) /tmp/cancel_test.py:CancelTest.test_iperf: CANCEL: iperf is not installed or wrong version (2.76 s) (2/2) /tmp/cancel_test.py:CancelTest.test_gcc: STARTED (2/2) /tmp/cancel_test.py:CancelTest.test_gcc: PASS (1.59 s) RESULTS : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 1 JOB TIME : 2.38 s JOB HTML : $HOME/avocado/job-results/job-2017-03-10T16.22-39c1f12/html/results.html Notice that using the ``self.cancel()`` will cancel the rest of the test from that point on, but the ``tearDown()`` will still be executed. Depending on the result format you're referring to, the ``CANCEL`` status is mapped to a corresponding valid status in that format. See the table below: +--------+----------------------+ | Format | Corresponding Status | +========+======================+ | json | cancel | +--------+----------------------+ | xunit | skipped | +--------+----------------------+ | tap | ok | +--------+----------------------+ | html | CANCEL (warning) | +--------+----------------------+ Docstring Directives -------------------- Some Avocado features, usually only available to instrumented tests, depend on setting directives on the test's class docstring. A docstring directive is composed of a marker (a literal ``:avocado:`` string), followed by the custom content itself, such as ``:avocado: directive``. This is similar to docstring directives such as ``:param my_param: description`` and shouldn't be a surprise to most Python developers. The reason Avocado uses those docstring directives (instead of real Python code) is that the inspection done while looking for tests does not involve any execution of code. For a detailed explanation about what makes a docstring format valid or not, please refer to our section on :ref:`docstring-directive-rules`. Now let's follow with some docstring directives examples. .. _docstring-directive-enable-disable: Declaring test as not being avocado-instrumented ------------------------------------------------ In order to say `this class is not an Avocado instrumented` test, one can use ``:avocado: disable`` directive. The result is that this class itself is not discovered as an instrumented test, but children classes might inherit it's ``test*`` methods (useful for base-classes):: from avocado import Test class BaseClass(Test): """ :avocado: disable """ def test_shared(self): pass class SpecificTests(BaseClass): def test_specific(self): pass Results in:: $ avocado list test.py avocado-instrumented test.py:SpecificTests.test_specific avocado-instrumented test.py:SpecificTests.test_shared The ``test.py:BaseBase.test`` is not discovered due the tag while the ``test.py:SpecificTests.test_shared`` is inherited from the base-class. Declaring test as being avocado-instrumented -------------------------------------------- The ``:avocado: enable`` tag might be useful when you want to override that this is an `avocado-instrumented` test, even though it is not inherited from ``avocado.Test`` class and/or when you want to only limit the ``test*`` methods discovery to the current class:: from avocado import Test class NotInheritedFromTest: """ :avocado: enable """ def test(self): pass class BaseClass(Test): """ :avocado: disable """ def test_shared(self): pass class SpecificTests(BaseClass): """ :avocado: enable """ def test_specific(self): pass Results in:: $ avocado list test.py avocado-instrumented test.py:NotInheritedFromTest.test avocado-instrumented test.py:SpecificTests.test_specific The ``test.py:NotInheritedFromTest.test`` will not really work as it lacks several required methods, but still is discovered as an `avocado-instrumented` test due to ``enable`` tag and the ``SpecificTests`` only looks at it's ``test*`` methods, ignoring the inheritance, therefore the ``test.py:SpecificTests.test_shared`` will not be discovered. (Deprecated) enabling recursive discovery ----------------------------------------- The ``:avocado: recursive`` tag was used to enable recursive discovery, but nowadays this is the default. By using this tag one explicitly sets the class as `avocado-instrumented`, therefore inheritance from `avocado.Test` is not required. .. _categorizing-tests: Categorizing tests ------------------ Avocado allows tests to be given tags, which can be used to create test categories. With tags set, users can select a subset of the tests found by the test resolver. To make this feature easier to grasp, let's work with an example: a single Python source code file, named ``perf.py``, that contains both disk and network performance tests:: from avocado import Test class Disk(Test): """ Disk performance tests :avocado: tags=disk,slow,superuser,unsafe """ def test_device(self): device = self.params.get('device', default='/dev/vdb') self.whiteboard = measure_write_to_disk(device) class Network(Test): """ Network performance tests :avocado: tags=net,fast,safe """ def test_latency(self): self.whiteboard = measure_latency() def test_throughput(self): self.whiteboard = measure_throughput() class Idle(Test): """ Idle tests """ def test_idle(self): self.whiteboard = "test achieved nothing" .. warning:: All docstring directives in Avocado require a strict format, that is, ``:avocado:`` followed by one or more spaces, and then followed by a single value **with no white spaces in between**. This means that an attempt to write a docstring directive like ``:avocado: tags=foo, bar`` will be interpreted as ``:avocado: tags=foo,``. .. _categorizing-tests-tags-on-methods: Test tags can be applied to test classes and to test methods. Tags are evaluated per method, meaning that the class tags will be inherited by all methods, being merged with method local tags. Example:: from avocado import Test class MyClass(Test): """ :avocado: tags=furious """ def test1(self): """ :avocado: tags=fast """ pass def test2(self): """ :avocado: tags=slow """ pass If you use the tag ``furious``, all tests will be included:: $ avocado list furious_tests.py --filter-by-tags=furious avocado-instrumented test_tags.py:MyClass.test1 avocado-instrumented test_tags.py:MyClass.test2 But using ``fast`` and ``furious`` will include only ``test1``:: $ avocado list furious_tests.py --filter-by-tags=fast,furious avocado-instrumented test_tags.py:MyClass.test1 .. _tags_keyval: Python :mod:`unittest` Compatibility Limitations And Caveats ------------------------------------------------------------ When executing tests, Avocado uses different techniques than most other Python unittest runners. This brings some compatibility limitations that Avocado users should be aware. Execution Model ~~~~~~~~~~~~~~~ One of the main differences is a consequence of the Avocado design decision that tests should be self contained and isolated from other tests. Additionally, the Avocado test runner runs each test in a separate process. If you have a unittest class with many test methods and run them using most test runners, you'll find that all test methods run under the same process. To check that behavior you could add to your :meth:`setUp ` method:: def setUp(self): print("PID: %s", os.getpid()) If you run the same test under Avocado, you'll find that each test is run on a separate process. Class Level :meth:`setUp ` and :meth:`tearDown ` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Because of Avocado's test execution model (each test is run on a separate process), it doesn't make sense to support unittest's :meth:`unittest.TestCase.setUpClass` and :meth:`unittest.TestCase.tearDownClass`. Test classes are freshly instantiated for each test, so it's pointless to run code in those methods, since they're supposed to keep class state between tests. The ``setUp`` method is the only place in Avocado where you are allowed to call the ``skip`` method, given that, if a test started to be executed, by definition it can't be skipped anymore. Avocado will do its best to enforce this boundary, so that if you use ``skip`` outside ``setUp``, the test upon execution will be marked with the ``ERROR`` status, and the error message will instruct you to fix your test's code. If you require a common setup to a number of tests, the current recommended approach is to to write regular :meth:`setUp ` and :meth:`tearDown ` code that checks if a given state was already set. One example for such a test that requires a binary installed by a package:: from avocado import Test from avocado.utils.software_manager import distro_packages from avocado.utils import path as utils_path from avocado.utils import process class BinSleep(Test): """ Sleeps using the /bin/sleep binary """ def setUp(self): self.sleep = None try: self.sleep = utils_path.find_command('sleep') except utils_path.CmdNotFoundError: distro_packages.install_distro_packages({'fedora': ['coreutils']}) self.sleep = utils_path.find_command('sleep') def test(self): process.run("%s 1" % self.sleep) If your test setup is some kind of action that will last across processes, like the installation of a software package given in the previous example, you're pretty much covered here. If you need to keep other type of data a class across test executions, you'll have to resort to saving and restoring the data from an outside source (say a "pickle" file). Finding and using a reliable and safe location for saving such data is currently not in the Avocado supported use cases. .. _environment-variables-for-tests: Environment Variables for Tests ------------------------------- Avocado exports some information, including test parameters, as environment variables to the running test. The availability of the variable depends on the test type. A greater set of variables are available to avocado-instrumented tests, while a reduced number of variables are available to EXEC tests. Although the availability of the variable, they are usually more interesting to EXEC tests. The reason is that EXEC tests can not make direct use of Avocado API. avocado-instrumented tests will usually have more powerful ways to access the same information. Here is a list of the variables that Avocado currently exports to avocado-instrumented tests: +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | Environment Variable | Meaning | Example | +=============================+=======================================+=====================================================================================================+ | AVOCADO_VERSION | Version of Avocado test runner | 92.0 | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_BASEDIR | Base directory of Avocado tests | $HOME/src/avocado/avocado.dev/examples/tests | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_WORKDIR | Work directory for the test | /var/tmp/.avocado-taskcx8of8di/test-results/tmp_dirfgqrnbu/1-Env.test | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TESTS_COMMON_TMPDIR | Temporary directory created by the | /var/tmp/avocado_cp07qzd9 | | | :ref:`plugin_teststmpdir` plugin. The| | | | directory is persistent throughout the| | | | tests in the same Job | | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_LOGDIR | Log directory for the test | /var/tmp/.avocado-task_5t_srpn/test-results/1-Env.test | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_LOGFILE | Log file for the test | /var/tmp/.avocado-taskcx8of8di/test-results/1-Env.test/debug.log | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_OUTPUTDIR | Output directory for the test | /var/tmp/.avocado-taskcx8of8di/test-results/1-Env.test/data | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | `***` | All variables from --mux-yaml | TIMEOUT=60; IO_WORKERS=10; VM_BYTES=512M; ... | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ Here is a list of the variables that Avocado currently exports to exec-test tests: +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | Environment Variable | Meaning | Example | +=============================+=======================================+=====================================================================================================+ | AVOCADO_VERSION | Version of Avocado test runner | 92.0 | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_BASEDIR | Base directory of Avocado tests | $HOME/src/avocado/avocado.dev/examples/tests | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_WORKDIR | Work directory for the test | /var/tmp/.avocado-taskcx8of8di/test-results/tmp_dirfgqrnbu/1-Env.test | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TESTS_COMMON_TMPDIR | Temporary directory created by the | /var/tmp/avocado_XhEdo/ | | | :ref:`plugin_teststmpdir` plugin. The| | | | directory is persistent throughout the| | | | tests in the same Job | | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_LOGDIR | Log directory for the test | /var/tmp/.avocado-task_5t_srpn/test-results/1-Env.test | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_LOGFILE | Log file for the test | /var/tmp/.avocado-taskcx8of8di/test-results/1-Env.test/debug.log | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | AVOCADO_TEST_OUTPUTDIR | Output directory for the test | /var/tmp/.avocado-taskcx8of8di/test-results/1-Env.test/data | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ | `***` | All variables from --mux-yaml | TIMEOUT=60; IO_WORKERS=10; VM_BYTES=512M; ... | +-----------------------------+---------------------------------------+-----------------------------------------------------------------------------------------------------+ SIMPLE Tests BASH extensions ---------------------------- SIMPLE tests written in shell can use a few Avocado utilities. In your shell code, check if the libraries are available with something like:: AVOCADO_SHELL_EXTENSIONS_DIR=$(avocado exec-path 2>/dev/null) And if available, injects that directory containing those utilities into the PATH used by the shell, making those utilities readily accessible:: if [ $? == 0 ]; then PATH=$AVOCADO_SHELL_EXTENSIONS_DIR:$PATH fi For a full list of utilities, take a look into at the directory return by ``avocado exec-path`` (if any). Also, the example test ``examples/tests/simplewarning.sh`` can serve as further inspiration. .. tip:: These extensions may be available as a separate package. For RPM packages, look for the ``bash`` sub-package. .. _docstring-directive-rules: Docstring Directives Rules -------------------------- Avocado avocado-instrumented tests, those written in Python and using the :class:`avocado.Test` API, can make use of special directives specified as docstrings. To be considered valid, the docstring must match this pattern: :data:`avocado.core.safeloader.docstring.DOCSTRING_DIRECTIVE_RE_RAW`. An Avocado docstring directive has two parts: 1) The marker, which is the literal string ``:avocado:``. 2) The content, a string that follows the marker, separated by at least one white space or tab. The following is a list of rules that makes a docstring directive be a valid one: * It should start with ``:avocado:``, which is the docstring directive "marker" * At least one whitespace or tab must follow the marker and precede the docstring directive "content" * The "content", which follows the marker and the space, must begin with an alphanumeric character, that is, characters within "a-z", "A-Z" or "0-9". * After at least one alphanumeric character, the content may contain the following special symbols too: ``_``, ``,``, ``=`` and ``:``. * An end of string (or end of line) must immediately follow the content. Signal Handlers --------------- Avocado normal operation is related to run code written by users/test-writers. It means the test code can carry its own handlers for different signals or even ignore then. Still, as the code is being executed by Avocado, we have to make sure we will finish all the subprocesses we create before ending our execution. Signals sent to the Avocado main process will be handled as follows: - SIGINT/Ctrl+C: This signal will be forwarded to the test process and Avocado will wait until it's finished. If the test process does not finish after receiving a SIGINT, user can send a second SIGINT (after the 2 seconds ignore period). The second SIGINT will make Avocado to send a SIGKILL to the whole subprocess tree and then complete the main process execution. - SIGTERM: This signal will make Avocado to terminate immediately. A SIGKILL will be sent to the whole subprocess tree and the main process will exit without completing the execution. Notice that it's a best-effort attempt, meaning that in case of fork-bomb, newly created processes might still be left behind. Wrap Up ------- We recommend you take a look at the example tests present in the ``examples/tests`` directory, that contains a few samples to take some inspiration from. That directory, besides containing examples, is also used by the Avocado self test suite to do functional testing of Avocado itself. Although one can inspire in ``__ where people are allowed to share their basic system tests. It is also recommended that you take a look at the :ref:`tests-api-reference`. for more possibilities. .. [#f1] sleeptest is a functional test for Avocado. It's "old" because we also have had such a test for `Autotest`_ for a long time. .. _Autotest: http://autotest.github.io .. _Class Names: https://www.python.org/dev/peps/pep-0008/ .. _PEP8 Function Names: https://www.python.org/dev/peps/pep-0008/#function-names