~launchpad-pqm/launchpad/devel

# Copyright 2009 Canonical Ltd.  This software is licensed under the

# GNU Affero General Public License version 3 (see the file LICENSE).

"""Support code for using a custom test result in test.py."""

__metaclass__ = type

__all__ = [

    'filter_tests',

    'patch_find_tests',

    ]

from unittest import TestSuite

from testtools import iterate_tests

from zope.testing.testrunner import find

def patch_find_tests(hook):

    """Add a post-processing hook to zope.testing.testrunner.find_tests.

    This is useful for things like filtering tests or listing tests.

    :param hook: A callable that takes the output of the real

        `testrunner.find_tests` and returns a thing with the same type and

        structure.

    """

    real_find_tests = find.find_tests

    def find_tests(*args):

        return hook(real_find_tests(*args))

    find.find_tests = find_tests

def filter_tests(list_name):

    """Create a hook for `patch_find_tests` that filters tests based on id.

    :param list_name: A filename that contains a newline-separated list of

        test ids, as generated by `list_tests`.

    :return: A callable that takes a result of `testrunner.find_tests` and

        returns only those tests with ids in the file 'list_name'.

    """

    def do_filter(tests_by_layer_name):

        tests = sorted(set(line.strip() for line in open(list_name, 'rb')))

        result = {}

        for layer_name, suite in tests_by_layer_name.iteritems():

            new_suite = TestSuite()

            for test in iterate_tests(suite):

                if test.id() in tests:

                    new_suite.addTest(test)

            if new_suite.countTestCases():

                result[layer_name] = new_suite

        return result

    return do_filter