Metadata-Version: 2.1
Name: pytest-xdist
Version: 2.1.0
Summary: pytest xdist plugin for distributed testing and loop-on-failing modes
Home-page: https://github.com/pytest-dev/pytest-xdist
Author: holger krekel and contributors
Author-email: pytest-dev@python.org,holger@merlinux.eu
License: MIT
Description: 
        
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            :target: https://pypi.python.org/pypi/pytest-xdist
        
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        xdist: pytest distributed testing plugin
        ========================================
        
        The `pytest-xdist`_ plugin extends pytest with some unique
        test execution modes:
        
        * test run parallelization_: if you have multiple CPUs or hosts you can use
          those for a combined test run.  This allows to speed up
          development or to use special resources of `remote machines`_.
        
        
        * ``--looponfail``: run your tests repeatedly in a subprocess.  After each run
          pytest waits until a file in your project changes and then re-runs
          the previously failing tests.  This is repeated until all tests pass
          after which again a full run is performed.
        
        * `Multi-Platform`_ coverage: you can specify different Python interpreters
          or different platforms and run tests in parallel on all of them.
        
        Before running tests remotely, ``pytest`` efficiently "rsyncs" your
        program source code to the remote place.  All test results
        are reported back and displayed to your local terminal.
        You may specify different Python versions and interpreters.
        
        If you would like to know how pytest-xdist works under the covers, checkout
        `OVERVIEW <https://github.com/pytest-dev/pytest-xdist/blob/master/OVERVIEW.md>`_.
        
        
        Installation
        ------------
        
        Install the plugin with::
        
            pip install pytest-xdist
        
        
        To use ``psutil`` for detection of the number of CPUs available, install the ``psutil`` extra::
        
            pip install pytest-xdist[psutil]
        
        
        .. _parallelization:
        
        Speed up test runs by sending tests to multiple CPUs
        ----------------------------------------------------
        
        To send tests to multiple CPUs, use the ``-n`` (or ``--numprocesses``) option::
        
            pytest -n NUMCPUS
        
        Pass ``-n auto`` to use as many processes as your computer has CPU cores. This
        can lead to considerable speed ups, especially if your test suite takes a
        noticeable amount of time.
        
        If a test crashes a worker, pytest-xdist will automatically restart that worker
        and report the test’s failure. You can use the ``--max-worker-restart`` option
        to limit the number of worker restarts that are allowed, or disable restarting
        altogether using ``--max-worker-restart 0``.
        
        By default, using ``--numprocesses`` will send pending tests to any worker that
        is available, without any guaranteed order. You can change the test
        distribution algorithm this with the ``--dist`` option. It takes these values:
        
        * ``--dist no``: The default algorithm, distributing one test at a time.
        
        * ``--dist loadscope``: Tests are grouped by **module** for *test functions*
          and by **class** for *test methods*. Groups are distributed to available
          workers as whole units. This guarantees that all tests in a group run in the
          same process. This can be useful if you have expensive module-level or
          class-level fixtures. Grouping by class takes priority over grouping by
          module.
        
        * ``--dist loadfile``: Tests are grouped by their containing file. Groups are
          distributed to available workers as whole units. This guarantees that all
          tests in a file run in the same worker.
        
        Making session-scoped fixtures execute only once
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        
        ``pytest-xdist`` is designed so that each worker process will perform its own collection and execute
        a subset of all tests. This means that tests in different processes requesting a high-level
        scoped fixture (for example ``session``) will execute the fixture code more than once, which
        breaks expectations and might be undesired in certain situations.
        
        While ``pytest-xdist`` does not have a builtin support for ensuring a session-scoped fixture is
        executed exactly once, this can be achieved by using a lock file for inter-process communication.
        
        The example below needs to execute the fixture ``session_data`` only once (because it is
        resource intensive, or needs to execute only once to define configuration options, etc), so it makes
        use of a `FileLock <https://pypi.org/project/filelock/>`_ to produce the fixture data only once
        when the first process requests the fixture, while the other processes will then read
        the data from a file.
        
        Here is the code:
        
        .. code-block:: python
        
            import json
        
            import pytest
            from filelock import FileLock
        
        
            @pytest.fixture(scope="session")
            def session_data(tmp_path_factory, worker_id):
                if worker_id == "master":
                    # not executing in with multiple workers, just produce the data and let
                    # pytest's fixture caching do its job
                    return produce_expensive_data()
        
                # get the temp directory shared by all workers
                root_tmp_dir = tmp_path_factory.getbasetemp().parent
        
                fn = root_tmp_dir / "data.json"
                with FileLock(str(fn) + ".lock"):
                    if fn.is_file():
                        data = json.loads(fn.read_text())
                    else:
                        data = produce_expensive_data()
                        fn.write_text(json.dumps(data))
                return data
        
        
        The example above can also be use in cases a fixture needs to execute exactly once per test session, like
        initializing a database service and populating initial tables.
        
        This technique might not work for every case, but should be a starting point for many situations
        where executing a high-scope fixture exactly once is important.
        
        Running tests in a Python subprocess
        ------------------------------------
        
        To instantiate a python3.5 subprocess and send tests to it, you may type::
        
            pytest -d --tx popen//python=python3.5
        
        This will start a subprocess which is run with the ``python3.5``
        Python interpreter, found in your system binary lookup path.
        
        If you prefix the --tx option value like this::
        
            --tx 3*popen//python=python3.5
        
        then three subprocesses would be created and tests
        will be load-balanced across these three processes.
        
        .. _boxed:
        
        Running tests in a boxed subprocess
        -----------------------------------
        
        This functionality has been moved to the
        `pytest-forked <https://github.com/pytest-dev/pytest-forked>`_ plugin, but the ``--boxed`` option
        is still kept for backward compatibility.
        
        .. _`remote machines`:
        
        Sending tests to remote SSH accounts
        ------------------------------------
        
        Suppose you have a package ``mypkg`` which contains some
        tests that you can successfully run locally. And you
        have a ssh-reachable machine ``myhost``.  Then
        you can ad-hoc distribute your tests by typing::
        
            pytest -d --tx ssh=myhostpopen --rsyncdir mypkg mypkg
        
        This will synchronize your :code:`mypkg` package directory
        to a remote ssh account and then locally collect tests
        and send them to remote places for execution.
        
        You can specify multiple :code:`--rsyncdir` directories
        to be sent to the remote side.
        
        .. note::
        
          For pytest to collect and send tests correctly
          you not only need to make sure all code and tests
          directories are rsynced, but that any test (sub) directory
          also has an :code:`__init__.py` file because internally
          pytest references tests as a fully qualified python
          module path.  **You will otherwise get strange errors**
          during setup of the remote side.
        
        
        You can specify multiple :code:`--rsyncignore` glob patterns
        to be ignored when file are sent to the remote side.
        There are also internal ignores: :code:`.*, *.pyc, *.pyo, *~`
        Those you cannot override using rsyncignore command-line or
        ini-file option(s).
        
        
        Sending tests to remote Socket Servers
        --------------------------------------
        
        Download the single-module `socketserver.py`_ Python program
        and run it like this::
        
            python socketserver.py
        
        It will tell you that it starts listening on the default
        port.  You can now on your home machine specify this
        new socket host with something like this::
        
            pytest -d --tx socket=192.168.1.102:8888 --rsyncdir mypkg mypkg
        
        
        .. _`atonce`:
        .. _`Multi-Platform`:
        
        
        Running tests on many platforms at once
        ---------------------------------------
        
        The basic command to run tests on multiple platforms is::
        
            pytest --dist=each --tx=spec1 --tx=spec2
        
        If you specify a windows host, an OSX host and a Linux
        environment this command will send each tests to all
        platforms - and report back failures from all platforms
        at once. The specifications strings use the `xspec syntax`_.
        
        .. _`xspec syntax`: http://codespeak.net/execnet/basics.html#xspec
        
        .. _`socketserver.py`: http://bitbucket.org/hpk42/execnet/raw/2af991418160/execnet/script/socketserver.py
        
        .. _`execnet`: http://codespeak.net/execnet
        
        Identifying the worker process during a test
        --------------------------------------------
        
        *New in version 1.15.*
        
        If you need to determine the identity of a worker process in
        a test or fixture, you may use the ``worker_id`` fixture to do so:
        
        .. code-block:: python
        
            @pytest.fixture()
            def user_account(worker_id):
                """ use a different account in each xdist worker """
                return "account_%s" % worker_id
        
        When ``xdist`` is disabled (running with ``-n0`` for example), then
        ``worker_id`` will return ``"master"``.
        
        Worker processes also have the following environment variables
        defined:
        
        * ``PYTEST_XDIST_WORKER``: the name of the worker, e.g., ``"gw2"``.
        * ``PYTEST_XDIST_WORKER_COUNT``: the total number of workers in this session,
          e.g., ``"4"`` when ``-n 4`` is given in the command-line.
        
        The information about the worker_id in a test is stored in the ``TestReport`` as
        well, under the ``worker_id`` attribute.
        
        Since version 2.0, the following functions are also available in the ``xdist`` module:
        
        .. code-block:: python
        
            def is_xdist_worker(request_or_session) -> bool:
                """Return `True` if this is an xdist worker, `False` otherwise
        
                :param request_or_session: the `pytest` `request` or `session` object
                """
        
            def is_xdist_master(request_or_session) -> bool:
                """Return `True` if this is the xdist master, `False` otherwise
        
                Note: this method also returns `False` when distribution has not been
                activated at all.
        
                :param request_or_session: the `pytest` `request` or `session` object
                """
        
            def get_xdist_worker_id(request_or_session) -> str:
                """Return the id of the current worker ('gw0', 'gw1', etc) or 'master'
                if running on the 'master' node.
        
                If not distributing tests (for example passing `-n0` or not passing `-n` at all) also return 'master'.
        
                :param request_or_session: the `pytest` `request` or `session` object
                """
        
        
        Uniquely identifying the current test run
        -----------------------------------------
        
        *New in version 1.32.*
        
        If you need to globally distinguish one test run from others in your
        workers, you can use the ``testrun_uid`` fixture. For instance, let's say you
        wanted to create a separate database for each test run:
        
        .. code-block:: python
        
            import pytest
            from posix_ipc import Semaphore, O_CREAT
        
            @pytest.fixture(scope="session", autouse=True)
            def create_unique_database(testrun_uid):
                """ create a unique database for this particular test run """
                database_url = f"psql://myapp-{testrun_uid}"
        
                with Semaphore(f"/{testrun_uid}-lock", flags=O_CREAT, initial_value=1):
                    if not database_exists(database_url):
                        create_database(database_url)
        
            @pytest.fixture()
            def db(testrun_uid):
                """ retrieve unique database """
                database_url = f"psql://myapp-{testrun_uid}"
                return database_get_instance(database_url)
        
        
        Additionally, during a test run, the following environment variable is defined:
        
        * ``PYTEST_XDIST_TESTRUNUID``: the unique id of the test run.
        
        Accessing ``sys.argv`` from the master node in workers
        ------------------------------------------------------
        
        To access the ``sys.argv`` passed to the command-line of the master node, use
        ``request.config.workerinput["mainargv"]``.
        
        
        Specifying test exec environments in an ini file
        ------------------------------------------------
        
        You can use pytest's ini file configuration to avoid typing common options.
        You can for example make running with three subprocesses your default like this:
        
        .. code-block:: ini
        
            [pytest]
            addopts = -n3
        
        You can also add default environments like this:
        
        .. code-block:: ini
        
            [pytest]
            addopts = --tx ssh=myhost//python=python3.5 --tx ssh=myhost//python=python3.6
        
        and then just type::
        
            pytest --dist=each
        
        to run tests in each of the environments.
        
        
        Specifying "rsync" dirs in an ini-file
        --------------------------------------
        
        In a ``tox.ini`` or ``setup.cfg`` file in your root project directory
        you may specify directories to include or to exclude in synchronisation:
        
        .. code-block:: ini
        
            [pytest]
            rsyncdirs = . mypkg helperpkg
            rsyncignore = .hg
        
        These directory specifications are relative to the directory
        where the configuration file was found.
        
        .. _`pytest-xdist`: http://pypi.python.org/pypi/pytest-xdist
        .. _`pytest-xdist repository`: https://github.com/pytest-dev/pytest-xdist
        .. _`pytest`: http://pytest.org
        
Platform: linux
Platform: osx
Platform: win32
Classifier: Development Status :: 5 - Production/Stable
Classifier: Framework :: Pytest
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: POSIX
Classifier: Operating System :: Microsoft :: Windows
Classifier: Operating System :: MacOS :: MacOS X
Classifier: Topic :: Software Development :: Testing
Classifier: Topic :: Software Development :: Quality Assurance
Classifier: Topic :: Utilities
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Requires-Python: >=3.5
Provides-Extra: testing
Provides-Extra: psutil
