os-brick/os_brick/tests/base.py

# -*- coding: utf-8 -*-

# Copyright 2010-2011 OpenStack Foundation
# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import logging
import os

import fixtures
import mock
from oslo_log import log as oslo_logging
from oslo_utils import strutils
from oslotest import base


LOG = oslo_logging.getLogger(__name__)


class TestCase(base.BaseTestCase):

    """Test case base class for all unit tests."""

    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()

        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
        try:
            test_timeout = int(test_timeout)
        except ValueError:
            # If timeout value is invalid do not set a timeout.
            test_timeout = 0
        if test_timeout > 0:
            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())

        environ_enabled = (lambda var_name:
                           strutils.bool_from_string(os.environ.get(var_name)))
        if environ_enabled('OS_STDOUT_CAPTURE'):
            stdout = self.useFixture(fixtures.StringStream('stdout')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
        if environ_enabled('OS_STDERR_CAPTURE'):
            stderr = self.useFixture(fixtures.StringStream('stderr')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))
        if environ_enabled('OS_LOG_CAPTURE'):
            log_format = '%(levelname)s [%(name)s] %(message)s'
            if environ_enabled('OS_DEBUG'):
                level = logging.DEBUG
            else:
                level = logging.INFO
            self.useFixture(fixtures.LoggerFixture(nuke_handlers=False,
                                                   format=log_format,
                                                   level=level))

    def _common_cleanup(self):
        """Runs after each test method to tear down test environment."""

        # Stop any timers
        for x in self.injected:
            try:
                x.stop()
            except AssertionError:
                pass

        # Delete attributes that don't start with _ so they don't pin
        # memory around unnecessarily for the duration of the test
        # suite
        for key in [k for k in self.__dict__.keys() if k[0] != '_']:
            del self.__dict__[key]

    def log_level(self, level):
        """Set logging level to the specified value."""
        log_root = logging.getLogger(None).logger
        log_root.setLevel(level)

    def mock_object(self, obj, attr_name, new_attr=None, **kwargs):
        """Use python mock to mock an object attribute

        Mocks the specified objects attribute with the given value.
        Automatically performs 'addCleanup' for the mock.

        """
        if not new_attr:
            new_attr = mock.Mock()
        patcher = mock.patch.object(obj, attr_name, new_attr, **kwargs)
        patcher.start()
        self.addCleanup(patcher.stop)

    # Useful assertions
    def assertDictMatch(self, d1, d2, approx_equal=False, tolerance=0.001):
        """Assert two dicts are equivalent.

        This is a 'deep' match in the sense that it handles nested
        dictionaries appropriately.

        NOTE:

            If you don't care (or don't know) a given value, you can specify
            the string DONTCARE as the value. This will cause that dict-item
            to be skipped.

        """
        def raise_assertion(msg):
            d1str = d1
            d2str = d2
            base_msg = ('Dictionaries do not match. %(msg)s d1: %(d1str)s '
                        'd2: %(d2str)s' %
                        {'msg': msg, 'd1str': d1str, 'd2str': d2str})
            raise AssertionError(base_msg)

        d1keys = set(d1.keys())
        d2keys = set(d2.keys())
        if d1keys != d2keys:
            d1only = d1keys - d2keys
            d2only = d2keys - d1keys
            raise_assertion('Keys in d1 and not d2: %(d1only)s. '
                            'Keys in d2 and not d1: %(d2only)s' %
                            {'d1only': d1only, 'd2only': d2only})

        for key in d1keys:
            d1value = d1[key]
            d2value = d2[key]
            try:
                error = abs(float(d1value) - float(d2value))
                within_tolerance = error <= tolerance
            except (ValueError, TypeError):
                # If both values aren't convertible to float, just ignore
                # ValueError if arg is a str, TypeError if it's something else
                # (like None)
                within_tolerance = False

            if hasattr(d1value, 'keys') and hasattr(d2value, 'keys'):
                self.assertDictMatch(d1value, d2value)
            elif 'DONTCARE' in (d1value, d2value):
                continue
            elif approx_equal and within_tolerance:
                continue
            elif d1value != d2value:
                raise_assertion("d1['%(key)s']=%(d1value)s != "
                                "d2['%(key)s']=%(d2value)s" %
                                {
                                    'key': key,
                                    'd1value': d1value,
                                    'd2value': d2value,
                                })