mirror of https://github.com/python/cpython
2286 lines
91 KiB
ReStructuredText
2286 lines
91 KiB
ReStructuredText
:mod:`unittest` --- Unit testing framework
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==========================================
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.. module:: unittest
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:synopsis: Unit testing framework for Python.
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.. moduleauthor:: Steve Purcell <stephen_purcell@yahoo.com>
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.. sectionauthor:: Steve Purcell <stephen_purcell@yahoo.com>
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.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
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.. sectionauthor:: Raymond Hettinger <python@rcn.com>
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**Source code:** :source:`Lib/unittest/__init__.py`
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--------------
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(If you are already familiar with the basic concepts of testing, you might want
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to skip to :ref:`the list of assert methods <assert-methods>`.)
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The :mod:`unittest` unit testing framework was originally inspired by JUnit
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and has a similar flavor as major unit testing frameworks in other
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languages. It supports test automation, sharing of setup and shutdown code
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for tests, aggregation of tests into collections, and independence of the
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tests from the reporting framework.
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To achieve this, :mod:`unittest` supports some important concepts in an
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object-oriented way:
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test fixture
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A :dfn:`test fixture` represents the preparation needed to perform one or more
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tests, and any associate cleanup actions. This may involve, for example,
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creating temporary or proxy databases, directories, or starting a server
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process.
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test case
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A :dfn:`test case` is the individual unit of testing. It checks for a specific
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response to a particular set of inputs. :mod:`unittest` provides a base class,
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:class:`TestCase`, which may be used to create new test cases.
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test suite
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A :dfn:`test suite` is a collection of test cases, test suites, or both. It is
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used to aggregate tests that should be executed together.
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test runner
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A :dfn:`test runner` is a component which orchestrates the execution of tests
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and provides the outcome to the user. The runner may use a graphical interface,
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a textual interface, or return a special value to indicate the results of
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executing the tests.
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.. seealso::
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Module :mod:`doctest`
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Another test-support module with a very different flavor.
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`Simple Smalltalk Testing: With Patterns <https://web.archive.org/web/20150315073817/http://www.xprogramming.com/testfram.htm>`_
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Kent Beck's original paper on testing frameworks using the pattern shared
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by :mod:`unittest`.
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`Nose <https://nose.readthedocs.org/en/latest/>`_ and `py.test <http://pytest.org>`_
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Third-party unittest frameworks with a lighter-weight syntax for writing
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tests. For example, ``assert func(10) == 42``.
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`The Python Testing Tools Taxonomy <https://wiki.python.org/moin/PythonTestingToolsTaxonomy>`_
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An extensive list of Python testing tools including functional testing
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frameworks and mock object libraries.
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`Testing in Python Mailing List <http://lists.idyll.org/listinfo/testing-in-python>`_
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A special-interest-group for discussion of testing, and testing tools,
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in Python.
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The script :file:`Tools/unittestgui/unittestgui.py` in the Python source distribution is
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a GUI tool for test discovery and execution. This is intended largely for ease of use
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for those new to unit testing. For production environments it is
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recommended that tests be driven by a continuous integration system such as
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`Buildbot <https://buildbot.net/>`_, `Jenkins <https://jenkins.io/>`_
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or `Hudson <http://hudson-ci.org/>`_.
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.. _unittest-minimal-example:
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Basic example
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-------------
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The :mod:`unittest` module provides a rich set of tools for constructing and
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running tests. This section demonstrates that a small subset of the tools
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suffice to meet the needs of most users.
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Here is a short script to test three string methods::
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import unittest
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class TestStringMethods(unittest.TestCase):
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def test_upper(self):
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self.assertEqual('foo'.upper(), 'FOO')
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def test_isupper(self):
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self.assertTrue('FOO'.isupper())
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self.assertFalse('Foo'.isupper())
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def test_split(self):
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s = 'hello world'
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self.assertEqual(s.split(), ['hello', 'world'])
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# check that s.split fails when the separator is not a string
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with self.assertRaises(TypeError):
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s.split(2)
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if __name__ == '__main__':
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unittest.main()
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A testcase is created by subclassing :class:`unittest.TestCase`. The three
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individual tests are defined with methods whose names start with the letters
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``test``. This naming convention informs the test runner about which methods
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represent tests.
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The crux of each test is a call to :meth:`~TestCase.assertEqual` to check for an
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expected result; :meth:`~TestCase.assertTrue` or :meth:`~TestCase.assertFalse`
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to verify a condition; or :meth:`~TestCase.assertRaises` to verify that a
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specific exception gets raised. These methods are used instead of the
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:keyword:`assert` statement so the test runner can accumulate all test results
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and produce a report.
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The :meth:`~TestCase.setUp` and :meth:`~TestCase.tearDown` methods allow you
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to define instructions that will be executed before and after each test method.
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They are covered in more detail in the section :ref:`organizing-tests`.
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The final block shows a simple way to run the tests. :func:`unittest.main`
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provides a command-line interface to the test script. When run from the command
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line, the above script produces an output that looks like this::
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...
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----------------------------------------------------------------------
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Ran 3 tests in 0.000s
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OK
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Passing the ``-v`` option to your test script will instruct :func:`unittest.main`
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to enable a higher level of verbosity, and produce the following output::
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test_isupper (__main__.TestStringMethods) ... ok
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test_split (__main__.TestStringMethods) ... ok
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test_upper (__main__.TestStringMethods) ... ok
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----------------------------------------------------------------------
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Ran 3 tests in 0.001s
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OK
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The above examples show the most commonly used :mod:`unittest` features which
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are sufficient to meet many everyday testing needs. The remainder of the
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documentation explores the full feature set from first principles.
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.. _unittest-command-line-interface:
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Command-Line Interface
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----------------------
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The unittest module can be used from the command line to run tests from
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modules, classes or even individual test methods::
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python -m unittest test_module1 test_module2
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python -m unittest test_module.TestClass
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python -m unittest test_module.TestClass.test_method
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You can pass in a list with any combination of module names, and fully
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qualified class or method names.
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Test modules can be specified by file path as well::
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python -m unittest tests/test_something.py
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This allows you to use the shell filename completion to specify the test module.
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The file specified must still be importable as a module. The path is converted
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to a module name by removing the '.py' and converting path separators into '.'.
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If you want to execute a test file that isn't importable as a module you should
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execute the file directly instead.
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You can run tests with more detail (higher verbosity) by passing in the -v flag::
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python -m unittest -v test_module
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When executed without arguments :ref:`unittest-test-discovery` is started::
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python -m unittest
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For a list of all the command-line options::
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python -m unittest -h
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.. versionchanged:: 3.2
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In earlier versions it was only possible to run individual test methods and
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not modules or classes.
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Command-line options
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~~~~~~~~~~~~~~~~~~~~
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:program:`unittest` supports these command-line options:
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.. program:: unittest
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.. cmdoption:: -b, --buffer
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The standard output and standard error streams are buffered during the test
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run. Output during a passing test is discarded. Output is echoed normally
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on test fail or error and is added to the failure messages.
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.. cmdoption:: -c, --catch
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:kbd:`Control-C` during the test run waits for the current test to end and then
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reports all the results so far. A second :kbd:`Control-C` raises the normal
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:exc:`KeyboardInterrupt` exception.
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See `Signal Handling`_ for the functions that provide this functionality.
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.. cmdoption:: -f, --failfast
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Stop the test run on the first error or failure.
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.. cmdoption:: --locals
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Show local variables in tracebacks.
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.. versionadded:: 3.2
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The command-line options ``-b``, ``-c`` and ``-f`` were added.
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.. versionadded:: 3.5
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The command-line option ``--locals``.
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The command line can also be used for test discovery, for running all of the
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tests in a project or just a subset.
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.. _unittest-test-discovery:
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Test Discovery
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--------------
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.. versionadded:: 3.2
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Unittest supports simple test discovery. In order to be compatible with test
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discovery, all of the test files must be :ref:`modules <tut-modules>` or
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:ref:`packages <tut-packages>` (including :term:`namespace packages
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<namespace package>`) importable from the top-level directory of
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the project (this means that their filenames must be valid :ref:`identifiers
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<identifiers>`).
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Test discovery is implemented in :meth:`TestLoader.discover`, but can also be
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used from the command line. The basic command-line usage is::
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cd project_directory
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python -m unittest discover
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.. note::
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As a shortcut, ``python -m unittest`` is the equivalent of
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``python -m unittest discover``. If you want to pass arguments to test
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discovery the ``discover`` sub-command must be used explicitly.
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The ``discover`` sub-command has the following options:
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.. program:: unittest discover
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.. cmdoption:: -v, --verbose
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Verbose output
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.. cmdoption:: -s, --start-directory directory
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Directory to start discovery (``.`` default)
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.. cmdoption:: -p, --pattern pattern
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Pattern to match test files (``test*.py`` default)
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.. cmdoption:: -t, --top-level-directory directory
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Top level directory of project (defaults to start directory)
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The :option:`-s`, :option:`-p`, and :option:`-t` options can be passed in
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as positional arguments in that order. The following two command lines
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are equivalent::
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python -m unittest discover -s project_directory -p "*_test.py"
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python -m unittest discover project_directory "*_test.py"
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As well as being a path it is possible to pass a package name, for example
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``myproject.subpackage.test``, as the start directory. The package name you
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supply will then be imported and its location on the filesystem will be used
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as the start directory.
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.. caution::
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Test discovery loads tests by importing them. Once test discovery has found
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all the test files from the start directory you specify it turns the paths
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into package names to import. For example :file:`foo/bar/baz.py` will be
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imported as ``foo.bar.baz``.
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If you have a package installed globally and attempt test discovery on
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a different copy of the package then the import *could* happen from the
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wrong place. If this happens test discovery will warn you and exit.
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If you supply the start directory as a package name rather than a
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path to a directory then discover assumes that whichever location it
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imports from is the location you intended, so you will not get the
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warning.
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Test modules and packages can customize test loading and discovery by through
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the `load_tests protocol`_.
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.. versionchanged:: 3.4
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Test discovery supports :term:`namespace packages <namespace package>`.
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.. _organizing-tests:
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Organizing test code
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--------------------
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The basic building blocks of unit testing are :dfn:`test cases` --- single
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scenarios that must be set up and checked for correctness. In :mod:`unittest`,
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test cases are represented by :class:`unittest.TestCase` instances.
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To make your own test cases you must write subclasses of
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:class:`TestCase` or use :class:`FunctionTestCase`.
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The testing code of a :class:`TestCase` instance should be entirely self
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contained, such that it can be run either in isolation or in arbitrary
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combination with any number of other test cases.
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The simplest :class:`TestCase` subclass will simply implement a test method
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(i.e. a method whose name starts with ``test``) in order to perform specific
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testing code::
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import unittest
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class DefaultWidgetSizeTestCase(unittest.TestCase):
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def test_default_widget_size(self):
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widget = Widget('The widget')
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self.assertEqual(widget.size(), (50, 50))
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Note that in order to test something, we use one of the :meth:`assert\*`
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methods provided by the :class:`TestCase` base class. If the test fails, an
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exception will be raised, and :mod:`unittest` will identify the test case as a
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:dfn:`failure`. Any other exceptions will be treated as :dfn:`errors`.
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Tests can be numerous, and their set-up can be repetitive. Luckily, we
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can factor out set-up code by implementing a method called
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:meth:`~TestCase.setUp`, which the testing framework will automatically
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call for every single test we run::
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import unittest
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class WidgetTestCase(unittest.TestCase):
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def setUp(self):
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self.widget = Widget('The widget')
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def test_default_widget_size(self):
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self.assertEqual(self.widget.size(), (50,50),
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'incorrect default size')
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def test_widget_resize(self):
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self.widget.resize(100,150)
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self.assertEqual(self.widget.size(), (100,150),
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'wrong size after resize')
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.. note::
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The order in which the various tests will be run is determined
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by sorting the test method names with respect to the built-in
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ordering for strings.
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If the :meth:`~TestCase.setUp` method raises an exception while the test is
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running, the framework will consider the test to have suffered an error, and
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the test method will not be executed.
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Similarly, we can provide a :meth:`~TestCase.tearDown` method that tidies up
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after the test method has been run::
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import unittest
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class WidgetTestCase(unittest.TestCase):
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def setUp(self):
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self.widget = Widget('The widget')
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def tearDown(self):
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self.widget.dispose()
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If :meth:`~TestCase.setUp` succeeded, :meth:`~TestCase.tearDown` will be
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run whether the test method succeeded or not.
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Such a working environment for the testing code is called a :dfn:`fixture`.
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Test case instances are grouped together according to the features they test.
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:mod:`unittest` provides a mechanism for this: the :dfn:`test suite`,
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represented by :mod:`unittest`'s :class:`TestSuite` class. In most cases,
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calling :func:`unittest.main` will do the right thing and collect all the
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module's test cases for you, and then execute them.
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However, should you want to customize the building of your test suite,
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you can do it yourself::
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def suite():
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suite = unittest.TestSuite()
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suite.addTest(WidgetTestCase('test_default_size'))
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suite.addTest(WidgetTestCase('test_resize'))
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return suite
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You can place the definitions of test cases and test suites in the same modules
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as the code they are to test (such as :file:`widget.py`), but there are several
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advantages to placing the test code in a separate module, such as
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:file:`test_widget.py`:
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* The test module can be run standalone from the command line.
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* The test code can more easily be separated from shipped code.
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* There is less temptation to change test code to fit the code it tests without
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a good reason.
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* Test code should be modified much less frequently than the code it tests.
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* Tested code can be refactored more easily.
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* Tests for modules written in C must be in separate modules anyway, so why not
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be consistent?
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* If the testing strategy changes, there is no need to change the source code.
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.. _legacy-unit-tests:
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Re-using old test code
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----------------------
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Some users will find that they have existing test code that they would like to
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run from :mod:`unittest`, without converting every old test function to a
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:class:`TestCase` subclass.
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For this reason, :mod:`unittest` provides a :class:`FunctionTestCase` class.
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This subclass of :class:`TestCase` can be used to wrap an existing test
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function. Set-up and tear-down functions can also be provided.
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Given the following test function::
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def testSomething():
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something = makeSomething()
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assert something.name is not None
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# ...
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one can create an equivalent test case instance as follows, with optional
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set-up and tear-down methods::
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testcase = unittest.FunctionTestCase(testSomething,
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setUp=makeSomethingDB,
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tearDown=deleteSomethingDB)
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.. note::
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Even though :class:`FunctionTestCase` can be used to quickly convert an
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existing test base over to a :mod:`unittest`\ -based system, this approach is
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not recommended. Taking the time to set up proper :class:`TestCase`
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subclasses will make future test refactorings infinitely easier.
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In some cases, the existing tests may have been written using the :mod:`doctest`
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module. If so, :mod:`doctest` provides a :class:`DocTestSuite` class that can
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automatically build :class:`unittest.TestSuite` instances from the existing
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:mod:`doctest`\ -based tests.
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.. _unittest-skipping:
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Skipping tests and expected failures
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------------------------------------
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.. versionadded:: 3.1
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Unittest supports skipping individual test methods and even whole classes of
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tests. In addition, it supports marking a test as an "expected failure," a test
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that is broken and will fail, but shouldn't be counted as a failure on a
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:class:`TestResult`.
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Skipping a test is simply a matter of using the :func:`skip` :term:`decorator`
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or one of its conditional variants.
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Basic skipping looks like this::
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class MyTestCase(unittest.TestCase):
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@unittest.skip("demonstrating skipping")
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def test_nothing(self):
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self.fail("shouldn't happen")
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@unittest.skipIf(mylib.__version__ < (1, 3),
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"not supported in this library version")
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def test_format(self):
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# Tests that work for only a certain version of the library.
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pass
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@unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
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def test_windows_support(self):
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# windows specific testing code
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pass
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This is the output of running the example above in verbose mode::
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test_format (__main__.MyTestCase) ... skipped 'not supported in this library version'
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test_nothing (__main__.MyTestCase) ... skipped 'demonstrating skipping'
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test_windows_support (__main__.MyTestCase) ... skipped 'requires Windows'
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----------------------------------------------------------------------
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Ran 3 tests in 0.005s
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OK (skipped=3)
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Classes can be skipped just like methods::
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@unittest.skip("showing class skipping")
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class MySkippedTestCase(unittest.TestCase):
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def test_not_run(self):
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pass
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:meth:`TestCase.setUp` can also skip the test. This is useful when a resource
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that needs to be set up is not available.
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Expected failures use the :func:`expectedFailure` decorator. ::
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class ExpectedFailureTestCase(unittest.TestCase):
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@unittest.expectedFailure
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def test_fail(self):
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self.assertEqual(1, 0, "broken")
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|
|
It's easy to roll your own skipping decorators by making a decorator that calls
|
|
:func:`skip` on the test when it wants it to be skipped. This decorator skips
|
|
the test unless the passed object has a certain attribute::
|
|
|
|
def skipUnlessHasattr(obj, attr):
|
|
if hasattr(obj, attr):
|
|
return lambda func: func
|
|
return unittest.skip("{!r} doesn't have {!r}".format(obj, attr))
|
|
|
|
The following decorators implement test skipping and expected failures:
|
|
|
|
.. decorator:: skip(reason)
|
|
|
|
Unconditionally skip the decorated test. *reason* should describe why the
|
|
test is being skipped.
|
|
|
|
.. decorator:: skipIf(condition, reason)
|
|
|
|
Skip the decorated test if *condition* is true.
|
|
|
|
.. decorator:: skipUnless(condition, reason)
|
|
|
|
Skip the decorated test unless *condition* is true.
|
|
|
|
.. decorator:: expectedFailure
|
|
|
|
Mark the test as an expected failure. If the test fails when run, the test
|
|
is not counted as a failure.
|
|
|
|
.. exception:: SkipTest(reason)
|
|
|
|
This exception is raised to skip a test.
|
|
|
|
Usually you can use :meth:`TestCase.skipTest` or one of the skipping
|
|
decorators instead of raising this directly.
|
|
|
|
Skipped tests will not have :meth:`~TestCase.setUp` or :meth:`~TestCase.tearDown` run around them.
|
|
Skipped classes will not have :meth:`~TestCase.setUpClass` or :meth:`~TestCase.tearDownClass` run.
|
|
Skipped modules will not have :func:`setUpModule` or :func:`tearDownModule` run.
|
|
|
|
|
|
.. _subtests:
|
|
|
|
Distinguishing test iterations using subtests
|
|
---------------------------------------------
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
When some of your tests differ only by a some very small differences, for
|
|
instance some parameters, unittest allows you to distinguish them inside
|
|
the body of a test method using the :meth:`~TestCase.subTest` context manager.
|
|
|
|
For example, the following test::
|
|
|
|
class NumbersTest(unittest.TestCase):
|
|
|
|
def test_even(self):
|
|
"""
|
|
Test that numbers between 0 and 5 are all even.
|
|
"""
|
|
for i in range(0, 6):
|
|
with self.subTest(i=i):
|
|
self.assertEqual(i % 2, 0)
|
|
|
|
will produce the following output::
|
|
|
|
======================================================================
|
|
FAIL: test_even (__main__.NumbersTest) (i=1)
|
|
----------------------------------------------------------------------
|
|
Traceback (most recent call last):
|
|
File "subtests.py", line 32, in test_even
|
|
self.assertEqual(i % 2, 0)
|
|
AssertionError: 1 != 0
|
|
|
|
======================================================================
|
|
FAIL: test_even (__main__.NumbersTest) (i=3)
|
|
----------------------------------------------------------------------
|
|
Traceback (most recent call last):
|
|
File "subtests.py", line 32, in test_even
|
|
self.assertEqual(i % 2, 0)
|
|
AssertionError: 1 != 0
|
|
|
|
======================================================================
|
|
FAIL: test_even (__main__.NumbersTest) (i=5)
|
|
----------------------------------------------------------------------
|
|
Traceback (most recent call last):
|
|
File "subtests.py", line 32, in test_even
|
|
self.assertEqual(i % 2, 0)
|
|
AssertionError: 1 != 0
|
|
|
|
Without using a subtest, execution would stop after the first failure,
|
|
and the error would be less easy to diagnose because the value of ``i``
|
|
wouldn't be displayed::
|
|
|
|
======================================================================
|
|
FAIL: test_even (__main__.NumbersTest)
|
|
----------------------------------------------------------------------
|
|
Traceback (most recent call last):
|
|
File "subtests.py", line 32, in test_even
|
|
self.assertEqual(i % 2, 0)
|
|
AssertionError: 1 != 0
|
|
|
|
|
|
.. _unittest-contents:
|
|
|
|
Classes and functions
|
|
---------------------
|
|
|
|
This section describes in depth the API of :mod:`unittest`.
|
|
|
|
|
|
.. _testcase-objects:
|
|
|
|
Test cases
|
|
~~~~~~~~~~
|
|
|
|
.. class:: TestCase(methodName='runTest')
|
|
|
|
Instances of the :class:`TestCase` class represent the logical test units
|
|
in the :mod:`unittest` universe. This class is intended to be used as a base
|
|
class, with specific tests being implemented by concrete subclasses. This class
|
|
implements the interface needed by the test runner to allow it to drive the
|
|
tests, and methods that the test code can use to check for and report various
|
|
kinds of failure.
|
|
|
|
Each instance of :class:`TestCase` will run a single base method: the method
|
|
named *methodName*.
|
|
In most uses of :class:`TestCase`, you will neither change
|
|
the *methodName* nor reimplement the default ``runTest()`` method.
|
|
|
|
.. versionchanged:: 3.2
|
|
:class:`TestCase` can be instantiated successfully without providing a
|
|
*methodName*. This makes it easier to experiment with :class:`TestCase`
|
|
from the interactive interpreter.
|
|
|
|
:class:`TestCase` instances provide three groups of methods: one group used
|
|
to run the test, another used by the test implementation to check conditions
|
|
and report failures, and some inquiry methods allowing information about the
|
|
test itself to be gathered.
|
|
|
|
Methods in the first group (running the test) are:
|
|
|
|
.. method:: setUp()
|
|
|
|
Method called to prepare the test fixture. This is called immediately
|
|
before calling the test method; other than :exc:`AssertionError` or :exc:`SkipTest`,
|
|
any exception raised by this method will be considered an error rather than
|
|
a test failure. The default implementation does nothing.
|
|
|
|
|
|
.. method:: tearDown()
|
|
|
|
Method called immediately after the test method has been called and the
|
|
result recorded. This is called even if the test method raised an
|
|
exception, so the implementation in subclasses may need to be particularly
|
|
careful about checking internal state. Any exception, other than
|
|
:exc:`AssertionError` or :exc:`SkipTest`, raised by this method will be
|
|
considered an additional error rather than a test failure (thus increasing
|
|
the total number of reported errors). This method will only be called if
|
|
the :meth:`setUp` succeeds, regardless of the outcome of the test method.
|
|
The default implementation does nothing.
|
|
|
|
|
|
.. method:: setUpClass()
|
|
|
|
A class method called before tests in an individual class run.
|
|
``setUpClass`` is called with the class as the only argument
|
|
and must be decorated as a :func:`classmethod`::
|
|
|
|
@classmethod
|
|
def setUpClass(cls):
|
|
...
|
|
|
|
See `Class and Module Fixtures`_ for more details.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
|
|
.. method:: tearDownClass()
|
|
|
|
A class method called after tests in an individual class have run.
|
|
``tearDownClass`` is called with the class as the only argument
|
|
and must be decorated as a :meth:`classmethod`::
|
|
|
|
@classmethod
|
|
def tearDownClass(cls):
|
|
...
|
|
|
|
See `Class and Module Fixtures`_ for more details.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
|
|
.. method:: run(result=None)
|
|
|
|
Run the test, collecting the result into the :class:`TestResult` object
|
|
passed as *result*. If *result* is omitted or ``None``, a temporary
|
|
result object is created (by calling the :meth:`defaultTestResult`
|
|
method) and used. The result object is returned to :meth:`run`'s
|
|
caller.
|
|
|
|
The same effect may be had by simply calling the :class:`TestCase`
|
|
instance.
|
|
|
|
.. versionchanged:: 3.3
|
|
Previous versions of ``run`` did not return the result. Neither did
|
|
calling an instance.
|
|
|
|
.. method:: skipTest(reason)
|
|
|
|
Calling this during a test method or :meth:`setUp` skips the current
|
|
test. See :ref:`unittest-skipping` for more information.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: subTest(msg=None, **params)
|
|
|
|
Return a context manager which executes the enclosed code block as a
|
|
subtest. *msg* and *params* are optional, arbitrary values which are
|
|
displayed whenever a subtest fails, allowing you to identify them
|
|
clearly.
|
|
|
|
A test case can contain any number of subtest declarations, and
|
|
they can be arbitrarily nested.
|
|
|
|
See :ref:`subtests` for more information.
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
|
|
.. method:: debug()
|
|
|
|
Run the test without collecting the result. This allows exceptions raised
|
|
by the test to be propagated to the caller, and can be used to support
|
|
running tests under a debugger.
|
|
|
|
.. _assert-methods:
|
|
|
|
The :class:`TestCase` class provides several assert methods to check for and
|
|
report failures. The following table lists the most commonly used methods
|
|
(see the tables below for more assert methods):
|
|
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| Method | Checks that | New in |
|
|
+=========================================+=============================+===============+
|
|
| :meth:`assertEqual(a, b) | ``a == b`` | |
|
|
| <TestCase.assertEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertNotEqual(a, b) | ``a != b`` | |
|
|
| <TestCase.assertNotEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertTrue(x) | ``bool(x) is True`` | |
|
|
| <TestCase.assertTrue>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertFalse(x) | ``bool(x) is False`` | |
|
|
| <TestCase.assertFalse>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIs(a, b) | ``a is b`` | 3.1 |
|
|
| <TestCase.assertIs>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIsNot(a, b) | ``a is not b`` | 3.1 |
|
|
| <TestCase.assertIsNot>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIsNone(x) | ``x is None`` | 3.1 |
|
|
| <TestCase.assertIsNone>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIsNotNone(x) | ``x is not None`` | 3.1 |
|
|
| <TestCase.assertIsNotNone>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIn(a, b) | ``a in b`` | 3.1 |
|
|
| <TestCase.assertIn>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertNotIn(a, b) | ``a not in b`` | 3.1 |
|
|
| <TestCase.assertNotIn>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertIsInstance(a, b) | ``isinstance(a, b)`` | 3.2 |
|
|
| <TestCase.assertIsInstance>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
| :meth:`assertNotIsInstance(a, b) | ``not isinstance(a, b)`` | 3.2 |
|
|
| <TestCase.assertNotIsInstance>` | | |
|
|
+-----------------------------------------+-----------------------------+---------------+
|
|
|
|
All the assert methods accept a *msg* argument that, if specified, is used
|
|
as the error message on failure (see also :data:`longMessage`).
|
|
Note that the *msg* keyword argument can be passed to :meth:`assertRaises`,
|
|
:meth:`assertRaisesRegex`, :meth:`assertWarns`, :meth:`assertWarnsRegex`
|
|
only when they are used as a context manager.
|
|
|
|
.. method:: assertEqual(first, second, msg=None)
|
|
|
|
Test that *first* and *second* are equal. If the values do not
|
|
compare equal, the test will fail.
|
|
|
|
In addition, if *first* and *second* are the exact same type and one of
|
|
list, tuple, dict, set, frozenset or str or any type that a subclass
|
|
registers with :meth:`addTypeEqualityFunc` the type-specific equality
|
|
function will be called in order to generate a more useful default
|
|
error message (see also the :ref:`list of type-specific methods
|
|
<type-specific-methods>`).
|
|
|
|
.. versionchanged:: 3.1
|
|
Added the automatic calling of type-specific equality function.
|
|
|
|
.. versionchanged:: 3.2
|
|
:meth:`assertMultiLineEqual` added as the default type equality
|
|
function for comparing strings.
|
|
|
|
|
|
.. method:: assertNotEqual(first, second, msg=None)
|
|
|
|
Test that *first* and *second* are not equal. If the values do
|
|
compare equal, the test will fail.
|
|
|
|
.. method:: assertTrue(expr, msg=None)
|
|
assertFalse(expr, msg=None)
|
|
|
|
Test that *expr* is true (or false).
|
|
|
|
Note that this is equivalent to ``bool(expr) is True`` and not to ``expr
|
|
is True`` (use ``assertIs(expr, True)`` for the latter). This method
|
|
should also be avoided when more specific methods are available (e.g.
|
|
``assertEqual(a, b)`` instead of ``assertTrue(a == b)``), because they
|
|
provide a better error message in case of failure.
|
|
|
|
|
|
.. method:: assertIs(first, second, msg=None)
|
|
assertIsNot(first, second, msg=None)
|
|
|
|
Test that *first* and *second* evaluate (or don't evaluate) to the
|
|
same object.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertIsNone(expr, msg=None)
|
|
assertIsNotNone(expr, msg=None)
|
|
|
|
Test that *expr* is (or is not) ``None``.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertIn(first, second, msg=None)
|
|
assertNotIn(first, second, msg=None)
|
|
|
|
Test that *first* is (or is not) in *second*.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertIsInstance(obj, cls, msg=None)
|
|
assertNotIsInstance(obj, cls, msg=None)
|
|
|
|
Test that *obj* is (or is not) an instance of *cls* (which can be a
|
|
class or a tuple of classes, as supported by :func:`isinstance`).
|
|
To check for the exact type, use :func:`assertIs(type(obj), cls) <assertIs>`.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
|
|
|
|
It is also possible to check the production of exceptions, warnings, and
|
|
log messages using the following methods:
|
|
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
| Method | Checks that | New in |
|
|
+=========================================================+======================================+============+
|
|
| :meth:`assertRaises(exc, fun, *args, **kwds) | ``fun(*args, **kwds)`` raises *exc* | |
|
|
| <TestCase.assertRaises>` | | |
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
| :meth:`assertRaisesRegex(exc, r, fun, *args, **kwds) | ``fun(*args, **kwds)`` raises *exc* | 3.1 |
|
|
| <TestCase.assertRaisesRegex>` | and the message matches regex *r* | |
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
| :meth:`assertWarns(warn, fun, *args, **kwds) | ``fun(*args, **kwds)`` raises *warn* | 3.2 |
|
|
| <TestCase.assertWarns>` | | |
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
| :meth:`assertWarnsRegex(warn, r, fun, *args, **kwds) | ``fun(*args, **kwds)`` raises *warn* | 3.2 |
|
|
| <TestCase.assertWarnsRegex>` | and the message matches regex *r* | |
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
| :meth:`assertLogs(logger, level) | The ``with`` block logs on *logger* | 3.4 |
|
|
| <TestCase.assertLogs>` | with minimum *level* | |
|
|
+---------------------------------------------------------+--------------------------------------+------------+
|
|
|
|
.. method:: assertRaises(exception, callable, *args, **kwds)
|
|
assertRaises(exception, msg=None)
|
|
|
|
Test that an exception is raised when *callable* is called with any
|
|
positional or keyword arguments that are also passed to
|
|
:meth:`assertRaises`. The test passes if *exception* is raised, is an
|
|
error if another exception is raised, or fails if no exception is raised.
|
|
To catch any of a group of exceptions, a tuple containing the exception
|
|
classes may be passed as *exception*.
|
|
|
|
If only the *exception* and possibly the *msg* arguments are given,
|
|
return a context manager so that the code under test can be written
|
|
inline rather than as a function::
|
|
|
|
with self.assertRaises(SomeException):
|
|
do_something()
|
|
|
|
When used as a context manager, :meth:`assertRaises` accepts the
|
|
additional keyword argument *msg*.
|
|
|
|
The context manager will store the caught exception object in its
|
|
:attr:`exception` attribute. This can be useful if the intention
|
|
is to perform additional checks on the exception raised::
|
|
|
|
with self.assertRaises(SomeException) as cm:
|
|
do_something()
|
|
|
|
the_exception = cm.exception
|
|
self.assertEqual(the_exception.error_code, 3)
|
|
|
|
.. versionchanged:: 3.1
|
|
Added the ability to use :meth:`assertRaises` as a context manager.
|
|
|
|
.. versionchanged:: 3.2
|
|
Added the :attr:`exception` attribute.
|
|
|
|
.. versionchanged:: 3.3
|
|
Added the *msg* keyword argument when used as a context manager.
|
|
|
|
|
|
.. method:: assertRaisesRegex(exception, regex, callable, *args, **kwds)
|
|
assertRaisesRegex(exception, regex, msg=None)
|
|
|
|
Like :meth:`assertRaises` but also tests that *regex* matches
|
|
on the string representation of the raised exception. *regex* may be
|
|
a regular expression object or a string containing a regular expression
|
|
suitable for use by :func:`re.search`. Examples::
|
|
|
|
self.assertRaisesRegex(ValueError, "invalid literal for.*XYZ'$",
|
|
int, 'XYZ')
|
|
|
|
or::
|
|
|
|
with self.assertRaisesRegex(ValueError, 'literal'):
|
|
int('XYZ')
|
|
|
|
.. versionadded:: 3.1
|
|
under the name ``assertRaisesRegexp``.
|
|
|
|
.. versionchanged:: 3.2
|
|
Renamed to :meth:`assertRaisesRegex`.
|
|
|
|
.. versionchanged:: 3.3
|
|
Added the *msg* keyword argument when used as a context manager.
|
|
|
|
|
|
.. method:: assertWarns(warning, callable, *args, **kwds)
|
|
assertWarns(warning, msg=None)
|
|
|
|
Test that a warning is triggered when *callable* is called with any
|
|
positional or keyword arguments that are also passed to
|
|
:meth:`assertWarns`. The test passes if *warning* is triggered and
|
|
fails if it isn't. Any exception is an error.
|
|
To catch any of a group of warnings, a tuple containing the warning
|
|
classes may be passed as *warnings*.
|
|
|
|
If only the *warning* and possibly the *msg* arguments are given,
|
|
return a context manager so that the code under test can be written
|
|
inline rather than as a function::
|
|
|
|
with self.assertWarns(SomeWarning):
|
|
do_something()
|
|
|
|
When used as a context manager, :meth:`assertWarns` accepts the
|
|
additional keyword argument *msg*.
|
|
|
|
The context manager will store the caught warning object in its
|
|
:attr:`warning` attribute, and the source line which triggered the
|
|
warnings in the :attr:`filename` and :attr:`lineno` attributes.
|
|
This can be useful if the intention is to perform additional checks
|
|
on the warning caught::
|
|
|
|
with self.assertWarns(SomeWarning) as cm:
|
|
do_something()
|
|
|
|
self.assertIn('myfile.py', cm.filename)
|
|
self.assertEqual(320, cm.lineno)
|
|
|
|
This method works regardless of the warning filters in place when it
|
|
is called.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. versionchanged:: 3.3
|
|
Added the *msg* keyword argument when used as a context manager.
|
|
|
|
|
|
.. method:: assertWarnsRegex(warning, regex, callable, *args, **kwds)
|
|
assertWarnsRegex(warning, regex, msg=None)
|
|
|
|
Like :meth:`assertWarns` but also tests that *regex* matches on the
|
|
message of the triggered warning. *regex* may be a regular expression
|
|
object or a string containing a regular expression suitable for use
|
|
by :func:`re.search`. Example::
|
|
|
|
self.assertWarnsRegex(DeprecationWarning,
|
|
r'legacy_function\(\) is deprecated',
|
|
legacy_function, 'XYZ')
|
|
|
|
or::
|
|
|
|
with self.assertWarnsRegex(RuntimeWarning, 'unsafe frobnicating'):
|
|
frobnicate('/etc/passwd')
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. versionchanged:: 3.3
|
|
Added the *msg* keyword argument when used as a context manager.
|
|
|
|
.. method:: assertLogs(logger=None, level=None)
|
|
|
|
A context manager to test that at least one message is logged on
|
|
the *logger* or one of its children, with at least the given
|
|
*level*.
|
|
|
|
If given, *logger* should be a :class:`logging.Logger` object or a
|
|
:class:`str` giving the name of a logger. The default is the root
|
|
logger, which will catch all messages.
|
|
|
|
If given, *level* should be either a numeric logging level or
|
|
its string equivalent (for example either ``"ERROR"`` or
|
|
:attr:`logging.ERROR`). The default is :attr:`logging.INFO`.
|
|
|
|
The test passes if at least one message emitted inside the ``with``
|
|
block matches the *logger* and *level* conditions, otherwise it fails.
|
|
|
|
The object returned by the context manager is a recording helper
|
|
which keeps tracks of the matching log messages. It has two
|
|
attributes:
|
|
|
|
.. attribute:: records
|
|
|
|
A list of :class:`logging.LogRecord` objects of the matching
|
|
log messages.
|
|
|
|
.. attribute:: output
|
|
|
|
A list of :class:`str` objects with the formatted output of
|
|
matching messages.
|
|
|
|
Example::
|
|
|
|
with self.assertLogs('foo', level='INFO') as cm:
|
|
logging.getLogger('foo').info('first message')
|
|
logging.getLogger('foo.bar').error('second message')
|
|
self.assertEqual(cm.output, ['INFO:foo:first message',
|
|
'ERROR:foo.bar:second message'])
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
|
|
There are also other methods used to perform more specific checks, such as:
|
|
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| Method | Checks that | New in |
|
|
+=======================================+================================+==============+
|
|
| :meth:`assertAlmostEqual(a, b) | ``round(a-b, 7) == 0`` | |
|
|
| <TestCase.assertAlmostEqual>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertNotAlmostEqual(a, b) | ``round(a-b, 7) != 0`` | |
|
|
| <TestCase.assertNotAlmostEqual>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertGreater(a, b) | ``a > b`` | 3.1 |
|
|
| <TestCase.assertGreater>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertGreaterEqual(a, b) | ``a >= b`` | 3.1 |
|
|
| <TestCase.assertGreaterEqual>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertLess(a, b) | ``a < b`` | 3.1 |
|
|
| <TestCase.assertLess>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertLessEqual(a, b) | ``a <= b`` | 3.1 |
|
|
| <TestCase.assertLessEqual>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertRegex(s, r) | ``r.search(s)`` | 3.1 |
|
|
| <TestCase.assertRegex>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertNotRegex(s, r) | ``not r.search(s)`` | 3.2 |
|
|
| <TestCase.assertNotRegex>` | | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
| :meth:`assertCountEqual(a, b) | *a* and *b* have the same | 3.2 |
|
|
| <TestCase.assertCountEqual>` | elements in the same number, | |
|
|
| | regardless of their order | |
|
|
+---------------------------------------+--------------------------------+--------------+
|
|
|
|
|
|
.. method:: assertAlmostEqual(first, second, places=7, msg=None, delta=None)
|
|
assertNotAlmostEqual(first, second, places=7, msg=None, delta=None)
|
|
|
|
Test that *first* and *second* are approximately (or not approximately)
|
|
equal by computing the difference, rounding to the given number of
|
|
decimal *places* (default 7), and comparing to zero. Note that these
|
|
methods round the values to the given number of *decimal places* (i.e.
|
|
like the :func:`round` function) and not *significant digits*.
|
|
|
|
If *delta* is supplied instead of *places* then the difference
|
|
between *first* and *second* must be less or equal to (or greater than) *delta*.
|
|
|
|
Supplying both *delta* and *places* raises a ``TypeError``.
|
|
|
|
.. versionchanged:: 3.2
|
|
:meth:`assertAlmostEqual` automatically considers almost equal objects
|
|
that compare equal. :meth:`assertNotAlmostEqual` automatically fails
|
|
if the objects compare equal. Added the *delta* keyword argument.
|
|
|
|
|
|
.. method:: assertGreater(first, second, msg=None)
|
|
assertGreaterEqual(first, second, msg=None)
|
|
assertLess(first, second, msg=None)
|
|
assertLessEqual(first, second, msg=None)
|
|
|
|
Test that *first* is respectively >, >=, < or <= than *second* depending
|
|
on the method name. If not, the test will fail::
|
|
|
|
>>> self.assertGreaterEqual(3, 4)
|
|
AssertionError: "3" unexpectedly not greater than or equal to "4"
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertRegex(text, regex, msg=None)
|
|
assertNotRegex(text, regex, msg=None)
|
|
|
|
Test that a *regex* search matches (or does not match) *text*. In case
|
|
of failure, the error message will include the pattern and the *text* (or
|
|
the pattern and the part of *text* that unexpectedly matched). *regex*
|
|
may be a regular expression object or a string containing a regular
|
|
expression suitable for use by :func:`re.search`.
|
|
|
|
.. versionadded:: 3.1
|
|
under the name ``assertRegexpMatches``.
|
|
.. versionchanged:: 3.2
|
|
The method ``assertRegexpMatches()`` has been renamed to
|
|
:meth:`.assertRegex`.
|
|
.. versionadded:: 3.2
|
|
:meth:`.assertNotRegex`.
|
|
.. versionadded:: 3.5
|
|
The name ``assertNotRegexpMatches`` is a deprecated alias
|
|
for :meth:`.assertNotRegex`.
|
|
|
|
|
|
.. method:: assertCountEqual(first, second, msg=None)
|
|
|
|
Test that sequence *first* contains the same elements as *second*,
|
|
regardless of their order. When they don't, an error message listing the
|
|
differences between the sequences will be generated.
|
|
|
|
Duplicate elements are *not* ignored when comparing *first* and
|
|
*second*. It verifies whether each element has the same count in both
|
|
sequences. Equivalent to:
|
|
``assertEqual(Counter(list(first)), Counter(list(second)))``
|
|
but works with sequences of unhashable objects as well.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
|
|
.. _type-specific-methods:
|
|
|
|
The :meth:`assertEqual` method dispatches the equality check for objects of
|
|
the same type to different type-specific methods. These methods are already
|
|
implemented for most of the built-in types, but it's also possible to
|
|
register new methods using :meth:`addTypeEqualityFunc`:
|
|
|
|
.. method:: addTypeEqualityFunc(typeobj, function)
|
|
|
|
Registers a type-specific method called by :meth:`assertEqual` to check
|
|
if two objects of exactly the same *typeobj* (not subclasses) compare
|
|
equal. *function* must take two positional arguments and a third msg=None
|
|
keyword argument just as :meth:`assertEqual` does. It must raise
|
|
:data:`self.failureException(msg) <failureException>` when inequality
|
|
between the first two parameters is detected -- possibly providing useful
|
|
information and explaining the inequalities in details in the error
|
|
message.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
The list of type-specific methods automatically used by
|
|
:meth:`~TestCase.assertEqual` are summarized in the following table. Note
|
|
that it's usually not necessary to invoke these methods directly.
|
|
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| Method | Used to compare | New in |
|
|
+=========================================+=============================+==============+
|
|
| :meth:`assertMultiLineEqual(a, b) | strings | 3.1 |
|
|
| <TestCase.assertMultiLineEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| :meth:`assertSequenceEqual(a, b) | sequences | 3.1 |
|
|
| <TestCase.assertSequenceEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| :meth:`assertListEqual(a, b) | lists | 3.1 |
|
|
| <TestCase.assertListEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| :meth:`assertTupleEqual(a, b) | tuples | 3.1 |
|
|
| <TestCase.assertTupleEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| :meth:`assertSetEqual(a, b) | sets or frozensets | 3.1 |
|
|
| <TestCase.assertSetEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
| :meth:`assertDictEqual(a, b) | dicts | 3.1 |
|
|
| <TestCase.assertDictEqual>` | | |
|
|
+-----------------------------------------+-----------------------------+--------------+
|
|
|
|
|
|
|
|
.. method:: assertMultiLineEqual(first, second, msg=None)
|
|
|
|
Test that the multiline string *first* is equal to the string *second*.
|
|
When not equal a diff of the two strings highlighting the differences
|
|
will be included in the error message. This method is used by default
|
|
when comparing strings with :meth:`assertEqual`.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertSequenceEqual(first, second, msg=None, seq_type=None)
|
|
|
|
Tests that two sequences are equal. If a *seq_type* is supplied, both
|
|
*first* and *second* must be instances of *seq_type* or a failure will
|
|
be raised. If the sequences are different an error message is
|
|
constructed that shows the difference between the two.
|
|
|
|
This method is not called directly by :meth:`assertEqual`, but
|
|
it's used to implement :meth:`assertListEqual` and
|
|
:meth:`assertTupleEqual`.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertListEqual(first, second, msg=None)
|
|
assertTupleEqual(first, second, msg=None)
|
|
|
|
Tests that two lists or tuples are equal. If not, an error message is
|
|
constructed that shows only the differences between the two. An error
|
|
is also raised if either of the parameters are of the wrong type.
|
|
These methods are used by default when comparing lists or tuples with
|
|
:meth:`assertEqual`.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertSetEqual(first, second, msg=None)
|
|
|
|
Tests that two sets are equal. If not, an error message is constructed
|
|
that lists the differences between the sets. This method is used by
|
|
default when comparing sets or frozensets with :meth:`assertEqual`.
|
|
|
|
Fails if either of *first* or *second* does not have a :meth:`set.difference`
|
|
method.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: assertDictEqual(first, second, msg=None)
|
|
|
|
Test that two dictionaries are equal. If not, an error message is
|
|
constructed that shows the differences in the dictionaries. This
|
|
method will be used by default to compare dictionaries in
|
|
calls to :meth:`assertEqual`.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
|
|
.. _other-methods-and-attrs:
|
|
|
|
Finally the :class:`TestCase` provides the following methods and attributes:
|
|
|
|
|
|
.. method:: fail(msg=None)
|
|
|
|
Signals a test failure unconditionally, with *msg* or ``None`` for
|
|
the error message.
|
|
|
|
|
|
.. attribute:: failureException
|
|
|
|
This class attribute gives the exception raised by the test method. If a
|
|
test framework needs to use a specialized exception, possibly to carry
|
|
additional information, it must subclass this exception in order to "play
|
|
fair" with the framework. The initial value of this attribute is
|
|
:exc:`AssertionError`.
|
|
|
|
|
|
.. attribute:: longMessage
|
|
|
|
This class attribute determines what happens when a custom failure message
|
|
is passed as the msg argument to an assertXYY call that fails.
|
|
``True`` is the default value. In this case, the custom message is appended
|
|
to the end of the standard failure message.
|
|
When set to ``False``, the custom message replaces the standard message.
|
|
|
|
The class setting can be overridden in individual test methods by assigning
|
|
an instance attribute, self.longMessage, to ``True`` or ``False`` before
|
|
calling the assert methods.
|
|
|
|
The class setting gets reset before each test call.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. attribute:: maxDiff
|
|
|
|
This attribute controls the maximum length of diffs output by assert
|
|
methods that report diffs on failure. It defaults to 80*8 characters.
|
|
Assert methods affected by this attribute are
|
|
:meth:`assertSequenceEqual` (including all the sequence comparison
|
|
methods that delegate to it), :meth:`assertDictEqual` and
|
|
:meth:`assertMultiLineEqual`.
|
|
|
|
Setting ``maxDiff`` to ``None`` means that there is no maximum length of
|
|
diffs.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
|
|
Testing frameworks can use the following methods to collect information on
|
|
the test:
|
|
|
|
|
|
.. method:: countTestCases()
|
|
|
|
Return the number of tests represented by this test object. For
|
|
:class:`TestCase` instances, this will always be ``1``.
|
|
|
|
|
|
.. method:: defaultTestResult()
|
|
|
|
Return an instance of the test result class that should be used for this
|
|
test case class (if no other result instance is provided to the
|
|
:meth:`run` method).
|
|
|
|
For :class:`TestCase` instances, this will always be an instance of
|
|
:class:`TestResult`; subclasses of :class:`TestCase` should override this
|
|
as necessary.
|
|
|
|
|
|
.. method:: id()
|
|
|
|
Return a string identifying the specific test case. This is usually the
|
|
full name of the test method, including the module and class name.
|
|
|
|
|
|
.. method:: shortDescription()
|
|
|
|
Returns a description of the test, or ``None`` if no description
|
|
has been provided. The default implementation of this method
|
|
returns the first line of the test method's docstring, if available,
|
|
or ``None``.
|
|
|
|
.. versionchanged:: 3.1
|
|
In 3.1 this was changed to add the test name to the short description
|
|
even in the presence of a docstring. This caused compatibility issues
|
|
with unittest extensions and adding the test name was moved to the
|
|
:class:`TextTestResult` in Python 3.2.
|
|
|
|
|
|
.. method:: addCleanup(function, *args, **kwargs)
|
|
|
|
Add a function to be called after :meth:`tearDown` to cleanup resources
|
|
used during the test. Functions will be called in reverse order to the
|
|
order they are added (:abbr:`LIFO (last-in, first-out)`). They
|
|
are called with any arguments and keyword arguments passed into
|
|
:meth:`addCleanup` when they are added.
|
|
|
|
If :meth:`setUp` fails, meaning that :meth:`tearDown` is not called,
|
|
then any cleanup functions added will still be called.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: doCleanups()
|
|
|
|
This method is called unconditionally after :meth:`tearDown`, or
|
|
after :meth:`setUp` if :meth:`setUp` raises an exception.
|
|
|
|
It is responsible for calling all the cleanup functions added by
|
|
:meth:`addCleanup`. If you need cleanup functions to be called
|
|
*prior* to :meth:`tearDown` then you can call :meth:`doCleanups`
|
|
yourself.
|
|
|
|
:meth:`doCleanups` pops methods off the stack of cleanup
|
|
functions one at a time, so it can be called at any time.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. class:: FunctionTestCase(testFunc, setUp=None, tearDown=None, description=None)
|
|
|
|
This class implements the portion of the :class:`TestCase` interface which
|
|
allows the test runner to drive the test, but does not provide the methods
|
|
which test code can use to check and report errors. This is used to create
|
|
test cases using legacy test code, allowing it to be integrated into a
|
|
:mod:`unittest`-based test framework.
|
|
|
|
|
|
.. _deprecated-aliases:
|
|
|
|
Deprecated aliases
|
|
##################
|
|
|
|
For historical reasons, some of the :class:`TestCase` methods had one or more
|
|
aliases that are now deprecated. The following table lists the correct names
|
|
along with their deprecated aliases:
|
|
|
|
============================== ====================== =======================
|
|
Method Name Deprecated alias Deprecated alias
|
|
============================== ====================== =======================
|
|
:meth:`.assertEqual` failUnlessEqual assertEquals
|
|
:meth:`.assertNotEqual` failIfEqual assertNotEquals
|
|
:meth:`.assertTrue` failUnless assert\_
|
|
:meth:`.assertFalse` failIf
|
|
:meth:`.assertRaises` failUnlessRaises
|
|
:meth:`.assertAlmostEqual` failUnlessAlmostEqual assertAlmostEquals
|
|
:meth:`.assertNotAlmostEqual` failIfAlmostEqual assertNotAlmostEquals
|
|
:meth:`.assertRegex` assertRegexpMatches
|
|
:meth:`.assertNotRegex` assertNotRegexpMatches
|
|
:meth:`.assertRaisesRegex` assertRaisesRegexp
|
|
============================== ====================== =======================
|
|
|
|
.. deprecated:: 3.1
|
|
the fail* aliases listed in the second column.
|
|
.. deprecated:: 3.2
|
|
the assert* aliases listed in the third column.
|
|
.. deprecated:: 3.2
|
|
``assertRegexpMatches`` and ``assertRaisesRegexp`` have been renamed to
|
|
:meth:`.assertRegex` and :meth:`.assertRaisesRegex`.
|
|
.. deprecated:: 3.5
|
|
the ``assertNotRegexpMatches`` name in favor of :meth:`.assertNotRegex`.
|
|
|
|
.. _testsuite-objects:
|
|
|
|
Grouping tests
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. class:: TestSuite(tests=())
|
|
|
|
This class represents an aggregation of individual test cases and test suites.
|
|
The class presents the interface needed by the test runner to allow it to be run
|
|
as any other test case. Running a :class:`TestSuite` instance is the same as
|
|
iterating over the suite, running each test individually.
|
|
|
|
If *tests* is given, it must be an iterable of individual test cases or other
|
|
test suites that will be used to build the suite initially. Additional methods
|
|
are provided to add test cases and suites to the collection later on.
|
|
|
|
:class:`TestSuite` objects behave much like :class:`TestCase` objects, except
|
|
they do not actually implement a test. Instead, they are used to aggregate
|
|
tests into groups of tests that should be run together. Some additional
|
|
methods are available to add tests to :class:`TestSuite` instances:
|
|
|
|
|
|
.. method:: TestSuite.addTest(test)
|
|
|
|
Add a :class:`TestCase` or :class:`TestSuite` to the suite.
|
|
|
|
|
|
.. method:: TestSuite.addTests(tests)
|
|
|
|
Add all the tests from an iterable of :class:`TestCase` and :class:`TestSuite`
|
|
instances to this test suite.
|
|
|
|
This is equivalent to iterating over *tests*, calling :meth:`addTest` for
|
|
each element.
|
|
|
|
:class:`TestSuite` shares the following methods with :class:`TestCase`:
|
|
|
|
|
|
.. method:: run(result)
|
|
|
|
Run the tests associated with this suite, collecting the result into the
|
|
test result object passed as *result*. Note that unlike
|
|
:meth:`TestCase.run`, :meth:`TestSuite.run` requires the result object to
|
|
be passed in.
|
|
|
|
|
|
.. method:: debug()
|
|
|
|
Run the tests associated with this suite without collecting the
|
|
result. This allows exceptions raised by the test to be propagated to the
|
|
caller and can be used to support running tests under a debugger.
|
|
|
|
|
|
.. method:: countTestCases()
|
|
|
|
Return the number of tests represented by this test object, including all
|
|
individual tests and sub-suites.
|
|
|
|
|
|
.. method:: __iter__()
|
|
|
|
Tests grouped by a :class:`TestSuite` are always accessed by iteration.
|
|
Subclasses can lazily provide tests by overriding :meth:`__iter__`. Note
|
|
that this method may be called several times on a single suite (for
|
|
example when counting tests or comparing for equality) so the tests
|
|
returned by repeated iterations before :meth:`TestSuite.run` must be the
|
|
same for each call iteration. After :meth:`TestSuite.run`, callers should
|
|
not rely on the tests returned by this method unless the caller uses a
|
|
subclass that overrides :meth:`TestSuite._removeTestAtIndex` to preserve
|
|
test references.
|
|
|
|
.. versionchanged:: 3.2
|
|
In earlier versions the :class:`TestSuite` accessed tests directly rather
|
|
than through iteration, so overriding :meth:`__iter__` wasn't sufficient
|
|
for providing tests.
|
|
|
|
.. versionchanged:: 3.4
|
|
In earlier versions the :class:`TestSuite` held references to each
|
|
:class:`TestCase` after :meth:`TestSuite.run`. Subclasses can restore
|
|
that behavior by overriding :meth:`TestSuite._removeTestAtIndex`.
|
|
|
|
In the typical usage of a :class:`TestSuite` object, the :meth:`run` method
|
|
is invoked by a :class:`TestRunner` rather than by the end-user test harness.
|
|
|
|
|
|
Loading and running tests
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: TestLoader()
|
|
|
|
The :class:`TestLoader` class is used to create test suites from classes and
|
|
modules. Normally, there is no need to create an instance of this class; the
|
|
:mod:`unittest` module provides an instance that can be shared as
|
|
:data:`unittest.defaultTestLoader`. Using a subclass or instance, however,
|
|
allows customization of some configurable properties.
|
|
|
|
:class:`TestLoader` objects have the following attributes:
|
|
|
|
|
|
.. attribute:: errors
|
|
|
|
A list of the non-fatal errors encountered while loading tests. Not reset
|
|
by the loader at any point. Fatal errors are signalled by the relevant
|
|
a method raising an exception to the caller. Non-fatal errors are also
|
|
indicated by a synthetic test that will raise the original error when
|
|
run.
|
|
|
|
.. versionadded:: 3.5
|
|
|
|
|
|
:class:`TestLoader` objects have the following methods:
|
|
|
|
|
|
.. method:: loadTestsFromTestCase(testCaseClass)
|
|
|
|
Return a suite of all test cases contained in the :class:`TestCase`\ -derived
|
|
:class:`testCaseClass`.
|
|
|
|
A test case instance is created for each method named by
|
|
:meth:`getTestCaseNames`. By default these are the method names
|
|
beginning with ``test``. If :meth:`getTestCaseNames` returns no
|
|
methods, but the :meth:`runTest` method is implemented, a single test
|
|
case is created for that method instead.
|
|
|
|
|
|
.. method:: loadTestsFromModule(module, pattern=None)
|
|
|
|
Return a suite of all test cases contained in the given module. This
|
|
method searches *module* for classes derived from :class:`TestCase` and
|
|
creates an instance of the class for each test method defined for the
|
|
class.
|
|
|
|
.. note::
|
|
|
|
While using a hierarchy of :class:`TestCase`\ -derived classes can be
|
|
convenient in sharing fixtures and helper functions, defining test
|
|
methods on base classes that are not intended to be instantiated
|
|
directly does not play well with this method. Doing so, however, can
|
|
be useful when the fixtures are different and defined in subclasses.
|
|
|
|
If a module provides a ``load_tests`` function it will be called to
|
|
load the tests. This allows modules to customize test loading.
|
|
This is the `load_tests protocol`_. The *pattern* argument is passed as
|
|
the third argument to ``load_tests``.
|
|
|
|
.. versionchanged:: 3.2
|
|
Support for ``load_tests`` added.
|
|
|
|
.. versionchanged:: 3.5
|
|
The undocumented and unofficial *use_load_tests* default argument is
|
|
deprecated and ignored, although it is still accepted for backward
|
|
compatibility. The method also now accepts a keyword-only argument
|
|
*pattern* which is passed to ``load_tests`` as the third argument.
|
|
|
|
|
|
.. method:: loadTestsFromName(name, module=None)
|
|
|
|
Return a suite of all test cases given a string specifier.
|
|
|
|
The specifier *name* is a "dotted name" that may resolve either to a
|
|
module, a test case class, a test method within a test case class, a
|
|
:class:`TestSuite` instance, or a callable object which returns a
|
|
:class:`TestCase` or :class:`TestSuite` instance. These checks are
|
|
applied in the order listed here; that is, a method on a possible test
|
|
case class will be picked up as "a test method within a test case class",
|
|
rather than "a callable object".
|
|
|
|
For example, if you have a module :mod:`SampleTests` containing a
|
|
:class:`TestCase`\ -derived class :class:`SampleTestCase` with three test
|
|
methods (:meth:`test_one`, :meth:`test_two`, and :meth:`test_three`), the
|
|
specifier ``'SampleTests.SampleTestCase'`` would cause this method to
|
|
return a suite which will run all three test methods. Using the specifier
|
|
``'SampleTests.SampleTestCase.test_two'`` would cause it to return a test
|
|
suite which will run only the :meth:`test_two` test method. The specifier
|
|
can refer to modules and packages which have not been imported; they will
|
|
be imported as a side-effect.
|
|
|
|
The method optionally resolves *name* relative to the given *module*.
|
|
|
|
.. versionchanged:: 3.5
|
|
If an :exc:`ImportError` or :exc:`AttributeError` occurs while traversing
|
|
*name* then a synthetic test that raises that error when run will be
|
|
returned. These errors are included in the errors accumulated by
|
|
self.errors.
|
|
|
|
|
|
.. method:: loadTestsFromNames(names, module=None)
|
|
|
|
Similar to :meth:`loadTestsFromName`, but takes a sequence of names rather
|
|
than a single name. The return value is a test suite which supports all
|
|
the tests defined for each name.
|
|
|
|
|
|
.. method:: getTestCaseNames(testCaseClass)
|
|
|
|
Return a sorted sequence of method names found within *testCaseClass*;
|
|
this should be a subclass of :class:`TestCase`.
|
|
|
|
|
|
.. method:: discover(start_dir, pattern='test*.py', top_level_dir=None)
|
|
|
|
Find all the test modules by recursing into subdirectories from the
|
|
specified start directory, and return a TestSuite object containing them.
|
|
Only test files that match *pattern* will be loaded. (Using shell style
|
|
pattern matching.) Only module names that are importable (i.e. are valid
|
|
Python identifiers) will be loaded.
|
|
|
|
All test modules must be importable from the top level of the project. If
|
|
the start directory is not the top level directory then the top level
|
|
directory must be specified separately.
|
|
|
|
If importing a module fails, for example due to a syntax error, then
|
|
this will be recorded as a single error and discovery will continue. If
|
|
the import failure is due to :exc:`SkipTest` being raised, it will be
|
|
recorded as a skip instead of an error.
|
|
|
|
If a package (a directory containing a file named :file:`__init__.py`) is
|
|
found, the package will be checked for a ``load_tests`` function. If this
|
|
exists then it will be called
|
|
``package.load_tests(loader, tests, pattern)``. Test discovery takes care
|
|
to ensure that a package is only checked for tests once during an
|
|
invocation, even if the load_tests function itself calls
|
|
``loader.discover``.
|
|
|
|
If ``load_tests`` exists then discovery does *not* recurse into the
|
|
package, ``load_tests`` is responsible for loading all tests in the
|
|
package.
|
|
|
|
The pattern is deliberately not stored as a loader attribute so that
|
|
packages can continue discovery themselves. *top_level_dir* is stored so
|
|
``load_tests`` does not need to pass this argument in to
|
|
``loader.discover()``.
|
|
|
|
*start_dir* can be a dotted module name as well as a directory.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. versionchanged:: 3.4
|
|
Modules that raise :exc:`SkipTest` on import are recorded as skips,
|
|
not errors.
|
|
Discovery works for :term:`namespace packages <namespace package>`.
|
|
Paths are sorted before being imported so that execution order is
|
|
the same even if the underlying file system's ordering is not
|
|
dependent on file name.
|
|
|
|
.. versionchanged:: 3.5
|
|
Found packages are now checked for ``load_tests`` regardless of
|
|
whether their path matches *pattern*, because it is impossible for
|
|
a package name to match the default pattern.
|
|
|
|
|
|
The following attributes of a :class:`TestLoader` can be configured either by
|
|
subclassing or assignment on an instance:
|
|
|
|
|
|
.. attribute:: testMethodPrefix
|
|
|
|
String giving the prefix of method names which will be interpreted as test
|
|
methods. The default value is ``'test'``.
|
|
|
|
This affects :meth:`getTestCaseNames` and all the :meth:`loadTestsFrom\*`
|
|
methods.
|
|
|
|
|
|
.. attribute:: sortTestMethodsUsing
|
|
|
|
Function to be used to compare method names when sorting them in
|
|
:meth:`getTestCaseNames` and all the :meth:`loadTestsFrom\*` methods.
|
|
|
|
|
|
.. attribute:: suiteClass
|
|
|
|
Callable object that constructs a test suite from a list of tests. No
|
|
methods on the resulting object are needed. The default value is the
|
|
:class:`TestSuite` class.
|
|
|
|
This affects all the :meth:`loadTestsFrom\*` methods.
|
|
|
|
|
|
.. class:: TestResult
|
|
|
|
This class is used to compile information about which tests have succeeded
|
|
and which have failed.
|
|
|
|
A :class:`TestResult` object stores the results of a set of tests. The
|
|
:class:`TestCase` and :class:`TestSuite` classes ensure that results are
|
|
properly recorded; test authors do not need to worry about recording the
|
|
outcome of tests.
|
|
|
|
Testing frameworks built on top of :mod:`unittest` may want access to the
|
|
:class:`TestResult` object generated by running a set of tests for reporting
|
|
purposes; a :class:`TestResult` instance is returned by the
|
|
:meth:`TestRunner.run` method for this purpose.
|
|
|
|
:class:`TestResult` instances have the following attributes that will be of
|
|
interest when inspecting the results of running a set of tests:
|
|
|
|
|
|
.. attribute:: errors
|
|
|
|
A list containing 2-tuples of :class:`TestCase` instances and strings
|
|
holding formatted tracebacks. Each tuple represents a test which raised an
|
|
unexpected exception.
|
|
|
|
.. attribute:: failures
|
|
|
|
A list containing 2-tuples of :class:`TestCase` instances and strings
|
|
holding formatted tracebacks. Each tuple represents a test where a failure
|
|
was explicitly signalled using the :meth:`TestCase.assert\*` methods.
|
|
|
|
.. attribute:: skipped
|
|
|
|
A list containing 2-tuples of :class:`TestCase` instances and strings
|
|
holding the reason for skipping the test.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
.. attribute:: expectedFailures
|
|
|
|
A list containing 2-tuples of :class:`TestCase` instances and strings
|
|
holding formatted tracebacks. Each tuple represents an expected failure
|
|
of the test case.
|
|
|
|
.. attribute:: unexpectedSuccesses
|
|
|
|
A list containing :class:`TestCase` instances that were marked as expected
|
|
failures, but succeeded.
|
|
|
|
.. attribute:: shouldStop
|
|
|
|
Set to ``True`` when the execution of tests should stop by :meth:`stop`.
|
|
|
|
.. attribute:: testsRun
|
|
|
|
The total number of tests run so far.
|
|
|
|
.. attribute:: buffer
|
|
|
|
If set to true, ``sys.stdout`` and ``sys.stderr`` will be buffered in between
|
|
:meth:`startTest` and :meth:`stopTest` being called. Collected output will
|
|
only be echoed onto the real ``sys.stdout`` and ``sys.stderr`` if the test
|
|
fails or errors. Any output is also attached to the failure / error message.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. attribute:: failfast
|
|
|
|
If set to true :meth:`stop` will be called on the first failure or error,
|
|
halting the test run.
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
.. attribute:: tb_locals
|
|
|
|
If set to true then local variables will be shown in tracebacks.
|
|
|
|
.. versionadded:: 3.5
|
|
|
|
.. method:: wasSuccessful()
|
|
|
|
Return ``True`` if all tests run so far have passed, otherwise returns
|
|
``False``.
|
|
|
|
.. versionchanged:: 3.4
|
|
Returns ``False`` if there were any :attr:`unexpectedSuccesses`
|
|
from tests marked with the :func:`expectedFailure` decorator.
|
|
|
|
.. method:: stop()
|
|
|
|
This method can be called to signal that the set of tests being run should
|
|
be aborted by setting the :attr:`shouldStop` attribute to ``True``.
|
|
:class:`TestRunner` objects should respect this flag and return without
|
|
running any additional tests.
|
|
|
|
For example, this feature is used by the :class:`TextTestRunner` class to
|
|
stop the test framework when the user signals an interrupt from the
|
|
keyboard. Interactive tools which provide :class:`TestRunner`
|
|
implementations can use this in a similar manner.
|
|
|
|
The following methods of the :class:`TestResult` class are used to maintain
|
|
the internal data structures, and may be extended in subclasses to support
|
|
additional reporting requirements. This is particularly useful in building
|
|
tools which support interactive reporting while tests are being run.
|
|
|
|
|
|
.. method:: startTest(test)
|
|
|
|
Called when the test case *test* is about to be run.
|
|
|
|
.. method:: stopTest(test)
|
|
|
|
Called after the test case *test* has been executed, regardless of the
|
|
outcome.
|
|
|
|
.. method:: startTestRun()
|
|
|
|
Called once before any tests are executed.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: stopTestRun()
|
|
|
|
Called once after all tests are executed.
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
|
|
.. method:: addError(test, err)
|
|
|
|
Called when the test case *test* raises an unexpected exception. *err* is a
|
|
tuple of the form returned by :func:`sys.exc_info`: ``(type, value,
|
|
traceback)``.
|
|
|
|
The default implementation appends a tuple ``(test, formatted_err)`` to
|
|
the instance's :attr:`errors` attribute, where *formatted_err* is a
|
|
formatted traceback derived from *err*.
|
|
|
|
|
|
.. method:: addFailure(test, err)
|
|
|
|
Called when the test case *test* signals a failure. *err* is a tuple of
|
|
the form returned by :func:`sys.exc_info`: ``(type, value, traceback)``.
|
|
|
|
The default implementation appends a tuple ``(test, formatted_err)`` to
|
|
the instance's :attr:`failures` attribute, where *formatted_err* is a
|
|
formatted traceback derived from *err*.
|
|
|
|
|
|
.. method:: addSuccess(test)
|
|
|
|
Called when the test case *test* succeeds.
|
|
|
|
The default implementation does nothing.
|
|
|
|
|
|
.. method:: addSkip(test, reason)
|
|
|
|
Called when the test case *test* is skipped. *reason* is the reason the
|
|
test gave for skipping.
|
|
|
|
The default implementation appends a tuple ``(test, reason)`` to the
|
|
instance's :attr:`skipped` attribute.
|
|
|
|
|
|
.. method:: addExpectedFailure(test, err)
|
|
|
|
Called when the test case *test* fails, but was marked with the
|
|
:func:`expectedFailure` decorator.
|
|
|
|
The default implementation appends a tuple ``(test, formatted_err)`` to
|
|
the instance's :attr:`expectedFailures` attribute, where *formatted_err*
|
|
is a formatted traceback derived from *err*.
|
|
|
|
|
|
.. method:: addUnexpectedSuccess(test)
|
|
|
|
Called when the test case *test* was marked with the
|
|
:func:`expectedFailure` decorator, but succeeded.
|
|
|
|
The default implementation appends the test to the instance's
|
|
:attr:`unexpectedSuccesses` attribute.
|
|
|
|
|
|
.. method:: addSubTest(test, subtest, outcome)
|
|
|
|
Called when a subtest finishes. *test* is the test case
|
|
corresponding to the test method. *subtest* is a custom
|
|
:class:`TestCase` instance describing the subtest.
|
|
|
|
If *outcome* is :const:`None`, the subtest succeeded. Otherwise,
|
|
it failed with an exception where *outcome* is a tuple of the form
|
|
returned by :func:`sys.exc_info`: ``(type, value, traceback)``.
|
|
|
|
The default implementation does nothing when the outcome is a
|
|
success, and records subtest failures as normal failures.
|
|
|
|
.. versionadded:: 3.4
|
|
|
|
|
|
.. class:: TextTestResult(stream, descriptions, verbosity)
|
|
|
|
A concrete implementation of :class:`TestResult` used by the
|
|
:class:`TextTestRunner`.
|
|
|
|
.. versionadded:: 3.2
|
|
This class was previously named ``_TextTestResult``. The old name still
|
|
exists as an alias but is deprecated.
|
|
|
|
|
|
.. data:: defaultTestLoader
|
|
|
|
Instance of the :class:`TestLoader` class intended to be shared. If no
|
|
customization of the :class:`TestLoader` is needed, this instance can be used
|
|
instead of repeatedly creating new instances.
|
|
|
|
|
|
.. class:: TextTestRunner(stream=None, descriptions=True, verbosity=1, failfast=False, \
|
|
buffer=False, resultclass=None, warnings=None, *, tb_locals=False)
|
|
|
|
A basic test runner implementation that outputs results to a stream. If *stream*
|
|
is ``None``, the default, :data:`sys.stderr` is used as the output stream. This class
|
|
has a few configurable parameters, but is essentially very simple. Graphical
|
|
applications which run test suites should provide alternate implementations. Such
|
|
implementations should accept ``**kwargs`` as the interface to construct runners
|
|
changes when features are added to unittest.
|
|
|
|
By default this runner shows :exc:`DeprecationWarning`,
|
|
:exc:`PendingDeprecationWarning`, :exc:`ResourceWarning` and
|
|
:exc:`ImportWarning` even if they are :ref:`ignored by default
|
|
<warning-ignored>`. Deprecation warnings caused by :ref:`deprecated unittest
|
|
methods <deprecated-aliases>` are also special-cased and, when the warning
|
|
filters are ``'default'`` or ``'always'``, they will appear only once
|
|
per-module, in order to avoid too many warning messages. This behavior can
|
|
be overridden using Python's :option:`!-Wd` or :option:`!-Wa` options
|
|
(see :ref:`Warning control <using-on-warnings>`) and leaving
|
|
*warnings* to ``None``.
|
|
|
|
.. versionchanged:: 3.2
|
|
Added the ``warnings`` argument.
|
|
|
|
.. versionchanged:: 3.2
|
|
The default stream is set to :data:`sys.stderr` at instantiation time rather
|
|
than import time.
|
|
|
|
.. versionchanged:: 3.5
|
|
Added the tb_locals parameter.
|
|
|
|
.. method:: _makeResult()
|
|
|
|
This method returns the instance of ``TestResult`` used by :meth:`run`.
|
|
It is not intended to be called directly, but can be overridden in
|
|
subclasses to provide a custom ``TestResult``.
|
|
|
|
``_makeResult()`` instantiates the class or callable passed in the
|
|
``TextTestRunner`` constructor as the ``resultclass`` argument. It
|
|
defaults to :class:`TextTestResult` if no ``resultclass`` is provided.
|
|
The result class is instantiated with the following arguments::
|
|
|
|
stream, descriptions, verbosity
|
|
|
|
.. method:: run(test)
|
|
|
|
This method is the main public interface to the `TextTestRunner`. This
|
|
method takes a :class:`TestSuite` or :class:`TestCase` instance. A
|
|
:class:`TestResult` is created by calling
|
|
:func:`_makeResult` and the test(s) are run and the
|
|
results printed to stdout.
|
|
|
|
|
|
.. function:: main(module='__main__', defaultTest=None, argv=None, testRunner=None, \
|
|
testLoader=unittest.defaultTestLoader, exit=True, verbosity=1, \
|
|
failfast=None, catchbreak=None, buffer=None, warnings=None)
|
|
|
|
A command-line program that loads a set of tests from *module* and runs them;
|
|
this is primarily for making test modules conveniently executable.
|
|
The simplest use for this function is to include the following line at the
|
|
end of a test script::
|
|
|
|
if __name__ == '__main__':
|
|
unittest.main()
|
|
|
|
You can run tests with more detailed information by passing in the verbosity
|
|
argument::
|
|
|
|
if __name__ == '__main__':
|
|
unittest.main(verbosity=2)
|
|
|
|
The *defaultTest* argument is either the name of a single test or an
|
|
iterable of test names to run if no test names are specified via *argv*. If
|
|
not specified or ``None`` and no test names are provided via *argv*, all
|
|
tests found in *module* are run.
|
|
|
|
The *argv* argument can be a list of options passed to the program, with the
|
|
first element being the program name. If not specified or ``None``,
|
|
the values of :data:`sys.argv` are used.
|
|
|
|
The *testRunner* argument can either be a test runner class or an already
|
|
created instance of it. By default ``main`` calls :func:`sys.exit` with
|
|
an exit code indicating success or failure of the tests run.
|
|
|
|
The *testLoader* argument has to be a :class:`TestLoader` instance,
|
|
and defaults to :data:`defaultTestLoader`.
|
|
|
|
``main`` supports being used from the interactive interpreter by passing in the
|
|
argument ``exit=False``. This displays the result on standard output without
|
|
calling :func:`sys.exit`::
|
|
|
|
>>> from unittest import main
|
|
>>> main(module='test_module', exit=False)
|
|
|
|
The *failfast*, *catchbreak* and *buffer* parameters have the same
|
|
effect as the same-name `command-line options`_.
|
|
|
|
The *warnings* argument specifies the :ref:`warning filter <warning-filter>`
|
|
that should be used while running the tests. If it's not specified, it will
|
|
remain ``None`` if a :option:`!-W` option is passed to :program:`python`
|
|
(see :ref:`Warning control <using-on-warnings>`),
|
|
otherwise it will be set to ``'default'``.
|
|
|
|
Calling ``main`` actually returns an instance of the ``TestProgram`` class.
|
|
This stores the result of the tests run as the ``result`` attribute.
|
|
|
|
.. versionchanged:: 3.1
|
|
The *exit* parameter was added.
|
|
|
|
.. versionchanged:: 3.2
|
|
The *verbosity*, *failfast*, *catchbreak*, *buffer*
|
|
and *warnings* parameters were added.
|
|
|
|
.. versionchanged:: 3.4
|
|
The *defaultTest* parameter was changed to also accept an iterable of
|
|
test names.
|
|
|
|
|
|
load_tests Protocol
|
|
###################
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
Modules or packages can customize how tests are loaded from them during normal
|
|
test runs or test discovery by implementing a function called ``load_tests``.
|
|
|
|
If a test module defines ``load_tests`` it will be called by
|
|
:meth:`TestLoader.loadTestsFromModule` with the following arguments::
|
|
|
|
load_tests(loader, standard_tests, pattern)
|
|
|
|
where *pattern* is passed straight through from ``loadTestsFromModule``. It
|
|
defaults to ``None``.
|
|
|
|
It should return a :class:`TestSuite`.
|
|
|
|
*loader* is the instance of :class:`TestLoader` doing the loading.
|
|
*standard_tests* are the tests that would be loaded by default from the
|
|
module. It is common for test modules to only want to add or remove tests
|
|
from the standard set of tests.
|
|
The third argument is used when loading packages as part of test discovery.
|
|
|
|
A typical ``load_tests`` function that loads tests from a specific set of
|
|
:class:`TestCase` classes may look like::
|
|
|
|
test_cases = (TestCase1, TestCase2, TestCase3)
|
|
|
|
def load_tests(loader, tests, pattern):
|
|
suite = TestSuite()
|
|
for test_class in test_cases:
|
|
tests = loader.loadTestsFromTestCase(test_class)
|
|
suite.addTests(tests)
|
|
return suite
|
|
|
|
If discovery is started in a directory containing a package, either from the
|
|
command line or by calling :meth:`TestLoader.discover`, then the package
|
|
:file:`__init__.py` will be checked for ``load_tests``. If that function does
|
|
not exist, discovery will recurse into the package as though it were just
|
|
another directory. Otherwise, discovery of the package's tests will be left up
|
|
to ``load_tests`` which is called with the following arguments::
|
|
|
|
load_tests(loader, standard_tests, pattern)
|
|
|
|
This should return a :class:`TestSuite` representing all the tests
|
|
from the package. (``standard_tests`` will only contain tests
|
|
collected from :file:`__init__.py`.)
|
|
|
|
Because the pattern is passed into ``load_tests`` the package is free to
|
|
continue (and potentially modify) test discovery. A 'do nothing'
|
|
``load_tests`` function for a test package would look like::
|
|
|
|
def load_tests(loader, standard_tests, pattern):
|
|
# top level directory cached on loader instance
|
|
this_dir = os.path.dirname(__file__)
|
|
package_tests = loader.discover(start_dir=this_dir, pattern=pattern)
|
|
standard_tests.addTests(package_tests)
|
|
return standard_tests
|
|
|
|
.. versionchanged:: 3.5
|
|
Discovery no longer checks package names for matching *pattern* due to the
|
|
impossibility of package names matching the default pattern.
|
|
|
|
|
|
|
|
Class and Module Fixtures
|
|
-------------------------
|
|
|
|
Class and module level fixtures are implemented in :class:`TestSuite`. When
|
|
the test suite encounters a test from a new class then :meth:`tearDownClass`
|
|
from the previous class (if there is one) is called, followed by
|
|
:meth:`setUpClass` from the new class.
|
|
|
|
Similarly if a test is from a different module from the previous test then
|
|
``tearDownModule`` from the previous module is run, followed by
|
|
``setUpModule`` from the new module.
|
|
|
|
After all the tests have run the final ``tearDownClass`` and
|
|
``tearDownModule`` are run.
|
|
|
|
Note that shared fixtures do not play well with [potential] features like test
|
|
parallelization and they break test isolation. They should be used with care.
|
|
|
|
The default ordering of tests created by the unittest test loaders is to group
|
|
all tests from the same modules and classes together. This will lead to
|
|
``setUpClass`` / ``setUpModule`` (etc) being called exactly once per class and
|
|
module. If you randomize the order, so that tests from different modules and
|
|
classes are adjacent to each other, then these shared fixture functions may be
|
|
called multiple times in a single test run.
|
|
|
|
Shared fixtures are not intended to work with suites with non-standard
|
|
ordering. A ``BaseTestSuite`` still exists for frameworks that don't want to
|
|
support shared fixtures.
|
|
|
|
If there are any exceptions raised during one of the shared fixture functions
|
|
the test is reported as an error. Because there is no corresponding test
|
|
instance an ``_ErrorHolder`` object (that has the same interface as a
|
|
:class:`TestCase`) is created to represent the error. If you are just using
|
|
the standard unittest test runner then this detail doesn't matter, but if you
|
|
are a framework author it may be relevant.
|
|
|
|
|
|
setUpClass and tearDownClass
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
These must be implemented as class methods::
|
|
|
|
import unittest
|
|
|
|
class Test(unittest.TestCase):
|
|
@classmethod
|
|
def setUpClass(cls):
|
|
cls._connection = createExpensiveConnectionObject()
|
|
|
|
@classmethod
|
|
def tearDownClass(cls):
|
|
cls._connection.destroy()
|
|
|
|
If you want the ``setUpClass`` and ``tearDownClass`` on base classes called
|
|
then you must call up to them yourself. The implementations in
|
|
:class:`TestCase` are empty.
|
|
|
|
If an exception is raised during a ``setUpClass`` then the tests in the class
|
|
are not run and the ``tearDownClass`` is not run. Skipped classes will not
|
|
have ``setUpClass`` or ``tearDownClass`` run. If the exception is a
|
|
:exc:`SkipTest` exception then the class will be reported as having been skipped
|
|
instead of as an error.
|
|
|
|
|
|
setUpModule and tearDownModule
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
These should be implemented as functions::
|
|
|
|
def setUpModule():
|
|
createConnection()
|
|
|
|
def tearDownModule():
|
|
closeConnection()
|
|
|
|
If an exception is raised in a ``setUpModule`` then none of the tests in the
|
|
module will be run and the ``tearDownModule`` will not be run. If the exception is a
|
|
:exc:`SkipTest` exception then the module will be reported as having been skipped
|
|
instead of as an error.
|
|
|
|
|
|
Signal Handling
|
|
---------------
|
|
|
|
.. versionadded:: 3.2
|
|
|
|
The :option:`-c/--catch <unittest -c>` command-line option to unittest,
|
|
along with the ``catchbreak`` parameter to :func:`unittest.main()`, provide
|
|
more friendly handling of control-C during a test run. With catch break
|
|
behavior enabled control-C will allow the currently running test to complete,
|
|
and the test run will then end and report all the results so far. A second
|
|
control-c will raise a :exc:`KeyboardInterrupt` in the usual way.
|
|
|
|
The control-c handling signal handler attempts to remain compatible with code or
|
|
tests that install their own :const:`signal.SIGINT` handler. If the ``unittest``
|
|
handler is called but *isn't* the installed :const:`signal.SIGINT` handler,
|
|
i.e. it has been replaced by the system under test and delegated to, then it
|
|
calls the default handler. This will normally be the expected behavior by code
|
|
that replaces an installed handler and delegates to it. For individual tests
|
|
that need ``unittest`` control-c handling disabled the :func:`removeHandler`
|
|
decorator can be used.
|
|
|
|
There are a few utility functions for framework authors to enable control-c
|
|
handling functionality within test frameworks.
|
|
|
|
.. function:: installHandler()
|
|
|
|
Install the control-c handler. When a :const:`signal.SIGINT` is received
|
|
(usually in response to the user pressing control-c) all registered results
|
|
have :meth:`~TestResult.stop` called.
|
|
|
|
|
|
.. function:: registerResult(result)
|
|
|
|
Register a :class:`TestResult` object for control-c handling. Registering a
|
|
result stores a weak reference to it, so it doesn't prevent the result from
|
|
being garbage collected.
|
|
|
|
Registering a :class:`TestResult` object has no side-effects if control-c
|
|
handling is not enabled, so test frameworks can unconditionally register
|
|
all results they create independently of whether or not handling is enabled.
|
|
|
|
|
|
.. function:: removeResult(result)
|
|
|
|
Remove a registered result. Once a result has been removed then
|
|
:meth:`~TestResult.stop` will no longer be called on that result object in
|
|
response to a control-c.
|
|
|
|
|
|
.. function:: removeHandler(function=None)
|
|
|
|
When called without arguments this function removes the control-c handler
|
|
if it has been installed. This function can also be used as a test decorator
|
|
to temporarily remove the handler whilst the test is being executed::
|
|
|
|
@unittest.removeHandler
|
|
def test_signal_handling(self):
|
|
...
|