improve and clarify skipping docs

This commit is contained in:
holger krekel 2011-03-05 13:08:43 +01:00
parent 318e8a404b
commit 22fac92ca0
2 changed files with 64 additions and 35 deletions

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@ -88,6 +88,16 @@ etc. Idea is to allow Python expressions which can operate
on common spellings for operating systems and python on common spellings for operating systems and python
interpreter versions. interpreter versions.
pytest.mark.xfail signature change
-------------------------------------------------------
tags: feature 2.1
change to pytest.mark.xfail(reason, (optional)condition)
to better implement the word meaning. It also signals
better that we always have some kind of an implementation
reason that can be formualated.
Compatibility? Maybe rename to "pytest.mark.xfail"?
introduce py.test.mark registration introduce py.test.mark registration
----------------------------------------- -----------------------------------------
tags: feature 2.1 tags: feature 2.1

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@ -1,20 +1,22 @@
.. _`skip and xfail`: .. _`skip and xfail`:
skip and xfail mechanisms skip and xfail: dealing with tests that can not succeed
===================================================================== =====================================================================
You can skip or "xfail" test functions, either by marking functions If you have test functions that cannot be run on certain platforms
with a decorator or by calling the ``pytest.skip|xfail`` functions. or that you expect to fail you can mark them accordingly or you
may call helper functions during execution of setup or test functions.
A *skip* means that you expect your test to pass unless a certain configuration or condition (e.g. wrong Python interpreter, missing dependency) prevents it to run. And *xfail* means that you expect your test to fail because there is an A *skip* means that you expect your test to pass unless a certain
implementation problem. py.test counts and lists *xfailing* tests separately configuration or condition (e.g. wrong Python interpreter, missing
and it is possible to give additional information, such as bug number or a URL. dependency) prevents it to run. And *xfail* means that your test
can run but you expect it to fail because there is an implementation problem.
Detailed information about skipped/xfailed tests is by default not shown py.test counts and lists *skip* and *xfail* tests separately. However,
at the end of a test run to avoid cluttering the output. You can use detailed information about skipped/xfailed tests is not shown by default
the ``-r`` option to see details corresponding to the "short" letters to avoid cluttering the output. You can use the ``-r`` option to see
shown in the test progress:: details corresponding to the "short" letters shown in the test
progress::
py.test -rxs # show extra info on skips and xfails py.test -rxs # show extra info on skips and xfails
@ -22,7 +24,7 @@ shown in the test progress::
.. _skipif: .. _skipif:
Skipping a single function Marking a test function to be skipped
------------------------------------------- -------------------------------------------
Here is an example of marking a test function to be skipped Here is an example of marking a test function to be skipped
@ -34,9 +36,9 @@ when run on a Python3 interpreter::
... ...
During test function setup the skipif condition is During test function setup the skipif condition is
evaluated by calling ``eval(expr, namespace)``. The namespace evaluated by calling ``eval('sys.version_info >= (3,0)', namespace)``.
contains all the module globals of the test function so that (*New in version 2.0.2*) The namespace contains all the module globals of the test function so that
you can for example check for versions:: you can for example check for versions of a module you are using::
import mymodule import mymodule
@ -44,23 +46,15 @@ you can for example check for versions::
def test_function(): def test_function():
... ...
The test function will be skipped and not run if The test function will not be run ("skipped") if
mymodule is below the specified version. The reason ``mymodule`` is below the specified version. The reason
for specifying the condition as a string is mainly that for specifying the condition as a string is mainly that
you can see more detailed reporting of xfail/skip reasons. py.test can report a summary of skip conditions.
For information on the construction of the ``namespace``
see `evaluation of skipif/xfail conditions`_.
Actually, the namespace is first initialized by You can of course create a shortcut for your conditional skip
putting the ``sys`` and ``os`` modules and the test decorator at module level like this::
``config`` object into it. And is then updated with
the module globals. The latter allows you to skip based
on a test configuration value::
@pytest.mark.skipif("not config.getvalue('db')")
def test_function(...):
...
You can create a shortcut for your conditional skip decorator
at module level like this::
win32only = pytest.mark.skipif("sys.platform != 'win32'") win32only = pytest.mark.skipif("sys.platform != 'win32'")
@ -68,11 +62,10 @@ at module level like this::
def test_function(): def test_function():
... ...
skip all test functions of a class skip all test functions of a class
-------------------------------------- --------------------------------------
As with all function :ref:`mark` you can skip test functions at the As with all function :ref:`marking <mark>` you can skip test functions at the
`whole class- or module level`_. Here is an example `whole class- or module level`_. Here is an example
for skipping all methods of a test class based on the platform:: for skipping all methods of a test class based on the platform::
@ -82,9 +75,10 @@ for skipping all methods of a test class based on the platform::
def test_function(self): def test_function(self):
"will not be setup or run under 'win32' platform" "will not be setup or run under 'win32' platform"
The ``pytestmark`` decorator will be applied to each test function. The ``pytestmark`` special name tells py.test to apply it to each test
If your code targets python2.6 or above you can equivalently use function in the class. If your code targets python2.6 or above you can
the skipif decorator on classes:: more naturally use the skipif decorator (and any other marker) on
classes::
@pytest.mark.skipif("sys.platform == 'win32'") @pytest.mark.skipif("sys.platform == 'win32'")
class TestPosixCalls: class TestPosixCalls:
@ -155,6 +149,31 @@ Running it with the report-on-xfail option gives this output::
======================== 6 xfailed in 0.06 seconds ========================= ======================== 6 xfailed in 0.06 seconds =========================
.. _`evaluation of skipif/xfail conditions`:
evaluation of skipif/xfail expressions
----------------------------------------------------
.. versionadded:: 2.0.2
The evaluation of a condition string in ``pytest.mark.skipif(conditionstring)``
or ``pytest.mark.xfail(conditionstring)`` takes place in a namespace
dictionary which is constructed as follows:
* the namespace is initialized by putting the ``sys`` and ``os`` modules
and the pytest ``config`` object into it.
* updated with the module globals of the test function for which the
expression is applied.
The pytest ``config`` object allows you to skip based on a test configuration value
which you might have added::
@pytest.mark.skipif("not config.getvalue('db')")
def test_function(...):
...
imperative xfail from within a test or setup function imperative xfail from within a test or setup function
------------------------------------------------------ ------------------------------------------------------