Fixed #20437 - marked a test-runner test as expected-fail under certain conditions.

from contextlib import contextmanager

import os

import sys

from django.test import TestCase

from django.test.runner import DiscoverRunner

from django.utils.unittest import expectedFailure

try:

    import unittest2

except ImportError:

    unittest2 = None

def expectedFailureIf(condition):

    """Marks a test as an expected failure if ``condition`` is met."""

    if condition:

        return expectedFailure

    return lambda func: func

class DiscoverRunnerTest(TestCase):

        self.assertEqual(count, 1)

    # this test fails if unittest2 is installed from PyPI on Python 2.6

    # refs https://code.djangoproject.com/ticket/20437

    @expectedFailureIf(sys.version_info < (2, 7) and unittest2)

    def test_dotted_test_method_vanilla_unittest(self):

        count = DiscoverRunner().build_suite(

            ["test_discovery_sample.tests_sample.TestVanillaUnittest.test_sample"],