Changing standard (Python) test discovery
===============================================

Changing directory recursion
-----------------------------------------------------

You can set the :confval:`norecursedirs` option in an ini-file, for example your ``setup.cfg`` in the project root directory::

    # content of setup.cfg
    [pytest]
    norecursedirs = .svn _build tmp*

This would tell py.test to not recurse into typical subversion or sphinx-build directories or into any ``tmp`` prefixed directory.

.. _`change naming conventions`:

Changing naming conventions
-----------------------------------------------------

You can configure different naming conventions by setting
the :confval:`python_files`, :confval:`python_classes` and
:confval:`python_functions` configuration options.  Example::

    # content of setup.cfg
    # can also be defined in in tox.ini or pytest.ini file
    [pytest]
    python_files=check_*.py
    python_classes=Check
    python_functions=check

This would make py.test look for ``check_`` prefixes in
Python filenames, ``Check`` prefixes in classes and ``check`` prefixes
in functions and classes.  For example, if we have::

    # content of check_myapp.py
    class CheckMyApp:
        def check_simple(self):
            pass
        def check_complex(self):
            pass

then the test collection looks like this::

    $ py.test --collectonly
    =========================== test session starts ============================
    platform darwin -- Python 2.7.1 -- pytest-2.2.2
    collecting ... collected 2 items
    <Module 'check_myapp.py'>
      <Class 'CheckMyApp'>
        <Instance '()'>
          <Function 'check_simple'>
          <Function 'check_complex'>
    
    =============================  in 0.01 seconds =============================

Interpreting cmdline arguments as Python packages
-----------------------------------------------------

You can use the ``--pyargs`` option to make py.test try
interpreting arguments as python package names, deriving
their file system path and then running the test. For
example if you have unittest2 installed you can type::

    py.test --pyargs unittest2.test.test_skipping -q

which would run the respective test module.  Like with
other options, through an ini-file and the :confval:`addopts` option you
can make this change more permanently::

    # content of pytest.ini
    [pytest]
    addopts = --pyargs

Now a simple invocation of ``py.test NAME`` will check
if NAME exists as an importable package/module and otherwise
treat it as a filesystem path.

Finding out what is collected
-----------------------------------------------

You can always peek at the collection tree without running tests like this::

    . $ py.test --collectonly pythoncollection.py
    =========================== test session starts ============================
    platform darwin -- Python 2.7.1 -- pytest-2.2.2
    collecting ... collected 3 items
    <Module 'pythoncollection.py'>
      <Function 'test_function'>
      <Class 'TestClass'>
        <Instance '()'>
          <Function 'test_method'>
          <Function 'test_anothermethod'>
    
    =============================  in 0.01 seconds =============================