attic.rst

ATTIC documentation

XXX REVIEW and remove the below XXX

Customizing the testing process

writing conftest.py files

You may put conftest.py files containing project-specific configuration in your project's root directory, it's usually best to put it just into the same directory level as your topmost __init__.py. In fact, pytest performs an "upwards" search starting from the directory that you specify to be tested and will lookup configuration values right-to-left. You may have options that reside e.g. in your home directory but note that project specific settings will be considered first. There is a flag that helps you debugging your conftest.py configurations:

pytest --trace-config

customizing the collecting and running process

To introduce different test items you can create one or more conftest.py files in your project. When the collection process traverses directories and modules the default collectors will produce custom Collectors and Items if they are found in a local conftest.py file.

Customizing the collection process in a module

If you have a module where you want to take responsibility for collecting your own test Items and possibly even for executing a test then you can provide `generative tests`_ that yield callables and possibly arguments as a tuple. This is especially useful for calling application test machinery with different parameter sets but counting each of the calls as a separate tests.

The other extension possibility is about specifying a custom test Item class which is responsible for setting up and executing an underlying test. Or you can extend the collection process for a whole directory tree by putting Items in a conftest.py configuration file. The collection process dynamically consults the chain of conftest.py modules to determine collectors and items at Directory, Module, Class, Function or Generator level respectively.

Customizing execution of Items and Functions

• pytest.Function test items control execution of a test function through its function.runtest() method. This method is responsible for performing setup and teardown ("Test Fixtures") for a test Function.
• Function.execute(target, *args) methods are invoked by the default Function.run() to actually execute a python function with the given (usually empty set of) arguments.

generative tests: yielding parametrized tests

Deprecated since 1.0 in favour of test generators.

Generative tests are test methods that are generator functions which yield callables and their arguments. This is useful for running a test function multiple times against different parameters. Example:

def test_generative():
    for x in (42,17,49):
        yield check, x

def check(arg):
    assert arg % 7 == 0   # second generated tests fails!

Note that test_generative() will cause three tests to get run, notably check(42), check(17) and check(49) of which the middle one will obviously fail.

To make it easier to distinguish the generated tests it is possible to specify an explicit name for them, like for example:

def test_generative():
    for x in (42,17,49):
        yield "case %d" % x, check, x

disabling a test class

If you want to disable a complete test class you can set the class-level attribute disabled. For example, in order to avoid running some tests on Win32:

class TestPosixOnly(object):
    disabled = sys.platform == 'win32'

    def test_xxx(self):
        ...