:orphan: .. _`pytest helpers`: Pytest API and builtin fixtures ================================================ Most of the information of this page has been moved over to :ref:`api-reference`. For information on plugin hooks and objects, see :ref:`plugins`. For information on the ``pytest.mark`` mechanism, see :ref:`mark`. For information about fixtures, see :ref:`fixtures`. To see a complete list of available fixtures (add ``-v`` to also see fixtures with leading ``_``), type : .. code-block:: pytest $ pytest -q --fixtures cache Return a cache object that can persist state between testing sessions. cache.get(key, default) cache.set(key, value) Keys must be ``/`` separated strings, where the first part is usually the name of your plugin or application to avoid clashes with other cache users. Values can be any object handled by the json stdlib module. capsys Enable text capturing of writes to ``sys.stdout`` and ``sys.stderr``. The captured output is made available via ``capsys.readouterr()`` method calls, which return a ``(out, err)`` namedtuple. ``out`` and ``err`` will be ``text`` objects. capsysbinary Enable bytes capturing of writes to ``sys.stdout`` and ``sys.stderr``. The captured output is made available via ``capsysbinary.readouterr()`` method calls, which return a ``(out, err)`` namedtuple. ``out`` and ``err`` will be ``bytes`` objects. capfd Enable text capturing of writes to file descriptors ``1`` and ``2``. The captured output is made available via ``capfd.readouterr()`` method calls, which return a ``(out, err)`` namedtuple. ``out`` and ``err`` will be ``text`` objects. capfdbinary Enable bytes capturing of writes to file descriptors ``1`` and ``2``. The captured output is made available via ``capfd.readouterr()`` method calls, which return a ``(out, err)`` namedtuple. ``out`` and ``err`` will be ``byte`` objects. doctest_namespace [session scope] Fixture that returns a :py:class:`dict` that will be injected into the namespace of doctests. pytestconfig [session scope] Session-scoped fixture that returns the :class:`_pytest.config.Config` object. Example:: def test_foo(pytestconfig): if pytestconfig.getoption("verbose") > 0: ... record_property Add extra properties to the calling test. User properties become part of the test report and are available to the configured reporters, like JUnit XML. The fixture is callable with ``name, value``. The value is automatically XML-encoded. Example:: def test_function(record_property): record_property("example_key", 1) record_xml_attribute Add extra xml attributes to the tag for the calling test. The fixture is callable with ``name, value``. The value is automatically XML-encoded. record_testsuite_property [session scope] Record a new ```` tag as child of the root ````. This is suitable to writing global information regarding the entire test suite, and is compatible with ``xunit2`` JUnit family. This is a ``session``-scoped fixture which is called with ``(name, value)``. Example: .. code-block:: python def test_foo(record_testsuite_property): record_testsuite_property("ARCH", "PPC") record_testsuite_property("STORAGE_TYPE", "CEPH") ``name`` must be a string, ``value`` will be converted to a string and properly xml-escaped. .. warning:: Currently this fixture **does not work** with the `pytest-xdist `__ plugin. See issue `#7767 `__ for details. caplog Access and control log capturing. Captured logs are available through the following properties/methods:: * caplog.messages -> list of format-interpolated log messages * caplog.text -> string containing formatted log output * caplog.records -> list of logging.LogRecord instances * caplog.record_tuples -> list of (logger_name, level, message) tuples * caplog.clear() -> clear captured records and formatted log output string monkeypatch A convenient fixture for monkey-patching. The fixture provides these methods to modify objects, dictionaries or os.environ:: monkeypatch.setattr(obj, name, value, raising=True) monkeypatch.delattr(obj, name, raising=True) monkeypatch.setitem(mapping, name, value) monkeypatch.delitem(obj, name, raising=True) monkeypatch.setenv(name, value, prepend=False) monkeypatch.delenv(name, raising=True) monkeypatch.syspath_prepend(path) monkeypatch.chdir(path) All modifications will be undone after the requesting test function or fixture has finished. The ``raising`` parameter determines if a KeyError or AttributeError will be raised if the set/deletion operation has no target. recwarn Return a :class:`WarningsRecorder` instance that records all warnings emitted by test functions. See https://docs.python.org/library/warnings.html for information on warning categories. tmpdir_factory [session scope] Return a :class:`pytest.TempdirFactory` instance for the test session. tmp_path_factory [session scope] Return a :class:`pytest.TempPathFactory` instance for the test session. tmpdir Return a temporary directory path object which is unique to each test function invocation, created as a sub directory of the base temporary directory. By default, a new base temporary directory is created each test session, and old bases are removed after 3 sessions, to aid in debugging. If ``--basetemp`` is used then it is cleared each session. See :ref:`base temporary directory`. The returned object is a `py.path.local`_ path object. .. _`py.path.local`: https://py.readthedocs.io/en/latest/path.html tmp_path Return a temporary directory path object which is unique to each test function invocation, created as a sub directory of the base temporary directory. By default, a new base temporary directory is created each test session, and old bases are removed after 3 sessions, to aid in debugging. If ``--basetemp`` is used then it is cleared each session. See :ref:`base temporary directory`. The returned object is a :class:`pathlib.Path` object. no tests ran in 0.12s You can also interactively ask for help, e.g. by typing on the Python interactive prompt something like: .. code-block:: python import pytest help(pytest)