test_ok2/doc/en/how-to/xunit_setup.rst

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.. _`classic xunit`:
.. _xunitsetup:
How to implement xunit-style set-up
========================================
This section describes a classic and popular way how you can implement
fixtures (setup and teardown test state) on a per-module/class/function basis.
.. note::
While these setup/teardown methods are simple and familiar to those
coming from a ``unittest`` or ``nose`` background, you may also consider
using pytest's more powerful :ref:`fixture mechanism
<fixture>` which leverages the concept of dependency injection, allowing
for a more modular and more scalable approach for managing test state,
especially for larger projects and for functional testing. You can
mix both fixture mechanisms in the same file but
test methods of ``unittest.TestCase`` subclasses
cannot receive fixture arguments.
Module level setup/teardown
--------------------------------------
If you have multiple test functions and test classes in a single
module you can optionally implement the following fixture methods
which will usually be called once for all the functions:
.. code-block:: python
def setup_module(module):
""" setup any state specific to the execution of the given module."""
def teardown_module(module):
"""teardown any state that was previously setup with a setup_module
method.
"""
As of pytest-3.0, the ``module`` parameter is optional.
Class level setup/teardown
----------------------------------
Similarly, the following methods are called at class level before
and after all test methods of the class are called:
.. code-block:: python
@classmethod
def setup_class(cls):
"""setup any state specific to the execution of the given class (which
usually contains tests).
"""
@classmethod
def teardown_class(cls):
"""teardown any state that was previously setup with a call to
setup_class.
"""
Method and function level setup/teardown
-----------------------------------------------
Similarly, the following methods are called around each method invocation:
.. code-block:: python
def setup_method(self, method):
"""setup any state tied to the execution of the given method in a
class. setup_method is invoked for every test method of a class.
"""
def teardown_method(self, method):
"""teardown any state that was previously setup with a setup_method
call.
"""
As of pytest-3.0, the ``method`` parameter is optional.
If you would rather define test functions directly at module level
you can also use the following functions to implement fixtures:
.. code-block:: python
def setup_function(function):
"""setup any state tied to the execution of the given function.
Invoked for every test function in the module.
"""
def teardown_function(function):
"""teardown any state that was previously setup with a setup_function
call.
"""
As of pytest-3.0, the ``function`` parameter is optional.
Remarks:
* It is possible for setup/teardown pairs to be invoked multiple times
per testing process.
* teardown functions are not called if the corresponding setup function existed
and failed/was skipped.
* Prior to pytest-4.2, xunit-style functions did not obey the scope rules of fixtures, so
it was possible, for example, for a ``setup_method`` to be called before a
session-scoped autouse fixture.
Now the xunit-style functions are integrated with the fixture mechanism and obey the proper
scope rules of fixtures involved in the call.