Changes between 2.3.5 and 2.4

known incompatibilities:

• if calling –genscript from python2.7 or above, you only get a standalone script which works on python2.7 or above. Use Python2.6 to also get a python2.5 compatible version.
• all xunit-style teardown methods (nose-style, pytest-style, unittest-style) will not be called if the corresponding setup method failed, see issue322 below.
• the pytest_plugin_unregister hook wasn’t ever properly called and there is no known implementation of the hook – so it got removed.
• pytest.fixture-decorated functions cannot be generators (i.e. use yield) anymore. This change might be reversed in 2.4.1 if it causes unforeseen real-life issues. However, you can always write and return an inner function/generator and change the fixture consumer to iterate over the returned generator. This change was done in lieu of the new pytest.yield_fixture decorator, see below.

new features:

• experimentally introduce a new pytest.yield_fixture decorator which accepts exactly the same parameters as pytest.fixture but mandates a yield statement instead of a return statement from fixture functions. This allows direct integration with “with-style” context managers in fixture functions and generally avoids registering of finalization callbacks in favour of treating the “after-yield” as teardown code. Thanks Andreas Pelme, Vladimir Keleshev, Floris Bruynooghe, Ronny Pfannschmidt and many others for discussions.

• allow boolean expression directly with skipif/xfail if a “reason” is also specified. Rework skipping documentation to recommend “condition as booleans” because it prevents surprises when importing markers between modules. Specifying conditions as strings will remain fully supported.

• reporting: color the last line red or green depending if failures/errors occured or everything passed. thanks Christian Theunert.

• make “import pdb ; pdb.set_trace()” work natively wrt capturing (no “-s” needed anymore), making pytest.set_trace() a mere shortcut.

• fix issue181: –pdb now also works on collect errors (and on internal errors) . This was implemented by a slight internal refactoring and the introduction of a new hook pytest_exception_interact hook (see next item).

• fix issue341: introduce new experimental hook for IDEs/terminals to intercept debugging: pytest_exception_interact(node, call, report).

• new monkeypatch.setattr() variant to provide a shorter invocation for patching out classes/functions from modules:

  monkeypatch.setattr(“requests.get”, myfunc)

  will replace the “get” function of the “requests” module with myfunc.

• fix issue322: tearDownClass is not run if setUpClass failed. Thanks Mathieu Agopian for the initial fix. Also make all of pytest/nose finalizer mimick the same generic behaviour: if a setupX exists and fails, don’t run teardownX. This internally introduces a new method “node.addfinalizer()” helper which can only be called during the setup phase of a node.

• simplify pytest.mark.parametrize() signature: allow to pass a CSV-separated string to specify argnames. For example: pytest.mark.parametrize("input,expected",  [(1,2), (2,3)]) works as well as the previous: pytest.mark.parametrize(("input", "expected"), ...).

• add support for setUpModule/tearDownModule detection, thanks Brian Okken.

• integrate tab-completion on options through use of “argcomplete”. Thanks Anthon van der Neut for the PR.

• change option names to be hyphen-separated long options but keep the old spelling backward compatible. py.test -h will only show the hyphenated version, for example “–collect-only” but “–collectonly” will remain valid as well (for backward-compat reasons). Many thanks to Anthon van der Neut for the implementation and to Hynek Schlawack for pushing us.

• fix issue 308 – allow to mark/xfail/skip individual parameter sets when parametrizing. Thanks Brianna Laugher.

• call new experimental pytest_load_initial_conftests hook to allow 3rd party plugins to do something before a conftest is loaded.

Bug fixes:

• fix issue358 – capturing options are now parsed more properly by using a new parser.parse_known_args method.
• pytest now uses argparse instead of optparse (thanks Anthon) which means that “argparse” is added as a dependency if installing into python2.6 environments or below.
• fix issue333: fix a case of bad unittest/pytest hook interaction.
• PR27: correctly handle nose.SkipTest during collection. Thanks Antonio Cuni, Ronny Pfannschmidt.
• fix issue355: junitxml puts name=”pytest” attribute to testsuite tag.
• fix issue336: autouse fixture in plugins should work again.
• fix issue279: improve object comparisons on assertion failure for standard datatypes and recognise collections.abc. Thanks to Brianna Laugher and Mathieu Agopian.
• fix issue317: assertion rewriter support for the is_package method
• fix issue335: document py.code.ExceptionInfo() object returned from pytest.raises(), thanks Mathieu Agopian.
• remove implicit distribute_setup support from setup.py.
• fix issue305: ignore any problems when writing pyc files.
• SO-17664702: call fixture finalizers even if the fixture function partially failed (finalizers would not always be called before)
• fix issue320 – fix class scope for fixtures when mixed with module-level functions. Thanks Anatloy Bubenkoff.
• you can specify “-q” or “-qq” to get different levels of “quieter” reporting (thanks Katarzyna Jachim)
• fix issue300 – Fix order of conftest loading when starting py.test in a subdirectory.
• fix issue323 – sorting of many module-scoped arg parametrizations
• make sessionfinish hooks execute with the same cwd-context as at session start (helps fix plugin behaviour which write output files with relative path such as pytest-cov)
• fix issue316 – properly reference collection hooks in docs
• fix issue 306 – cleanup of -k/-m options to only match markers/test names/keywords respectively. Thanks Wouter van Ackooy.
• improved doctest counting for doctests in python modules — files without any doctest items will not show up anymore and doctest examples are counted as separate test items. thanks Danilo Bellini.
• fix issue245 by depending on the released py-1.4.14 which fixes py.io.dupfile to work with files with no mode. Thanks Jason R. Coombs.
• fix junitxml generation when test output contains control characters, addressing issue267, thanks Jaap Broekhuizen
• fix issue338: honor –tb style for setup/teardown errors as well. Thanks Maho.
• fix issue307 – use yaml.safe_load in example, thanks Mark Eichin.
• better parametrize error messages, thanks Brianna Laugher
• pytest_terminal_summary(terminalreporter) hooks can now use “.section(title)” and “.line(msg)” methods to print extra information at the end of a test run.