wexpect-venv/tests/PexpectTestCase.py

'''
PEXPECT LICENSE

    This license is approved by the OSI and FSF as GPL-compatible.
        http://opensource.org/licenses/isc-license.txt

    Copyright (c) 2012, Noah Spurrier <noah@noah.org>
    PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
    PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
    COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

'''
from __future__ import print_function

import contextlib
import unittest
import signal
import sys
import os


class PexpectTestCase(unittest.TestCase):
    def setUp(self):
        self.PYTHONBIN = sys.executable
        self.original_path = os.getcwd()
        tests_dir = os.path.dirname(__file__)
        self.project_dir = project_dir = os.path.dirname(tests_dir)

        # all tests are executed in this folder; there are many auxiliary
        # programs in this folder executed by spawn().
        os.chdir(tests_dir)

        # If the pexpect raises an exception after fork(), but before
        # exec(), our test runner *also* forks.  We prevent this by
        # storing our pid and asserting equality on tearDown.
        self.pid = os.getpid()

        coverage_rc = os.path.join(project_dir, '.coveragerc')
        os.environ['COVERAGE_PROCESS_START'] = coverage_rc
        os.environ['COVERAGE_FILE'] = os.path.join(project_dir, '.coverage')
        print('\n', self.id(), end=' ')
        sys.stdout.flush()

        # some build agents will ignore SIGHUP and SIGINT, which python
        # inherits.  This causes some of the tests related to terminate()
        # to fail.  We set them to the default handlers that they should
        # be, and restore them back to their SIG_IGN value on tearDown.
        #
        # I'm not entirely convinced they need to be restored, only our
        # test runner is affected.
        self.restore_ignored_signals = [
            value for value in (signal.SIGINT,)
            if signal.getsignal(value) == signal.SIG_IGN]
        if signal.SIGINT in self.restore_ignored_signals:
            # SIGINT should be set to signal.default_int_handler
            signal.signal(signal.SIGINT, signal.default_int_handler)
        unittest.TestCase.setUp(self)

    def tearDown(self):
        # restore original working folder
        os.chdir(self.original_path)

        if self.pid != os.getpid():
            # The build server pattern-matches phrase 'Test runner has forked!'
            print("Test runner has forked! This means a child process raised "
                  "an exception before exec() in a test case, the error is "
                  "more than likely found above this line in stderr.",
                  file=sys.stderr)
            exit(1)

        # restore signal handlers
        for signal_value in self.restore_ignored_signals:
            signal.signal(signal_value, signal.SIG_IGN)

    if sys.version_info < (2, 7):
        # We want to use these methods, which are new/improved in 2.7, but
        # we are still supporting 2.6 for the moment. This section can be
        # removed when we drop Python 2.6 support.
        @contextlib.contextmanager
        def assertRaises(self, excClass):
            try:
                yield
            except Exception as e:
                assert isinstance(e, excClass)
            else:
                raise AssertionError("%s was not raised" % excClass)

        @contextlib.contextmanager
        def assertRaisesRegexp(self, excClass, pattern):
            import re
            try:
                yield
            except Exception as e:
                assert isinstance(e, excClass)
                assert re.match(pattern, str(e))
            else:
                raise AssertionError("%s was not raised" % excClass)