text: # Copyright 2018 Red Hat, Inc.
  #
  #    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.
  
  from nova import context
  from nova import exception_wrapper
  from nova import test
  from nova.tests import fixtures
  
  
  class TestNotificationFixture(test.NoDBTestCase):
      def setUp(self):
          super(TestNotificationFixture, self).setUp()
  
          self.notifier = self.useFixture(fixtures.NotificationFixture(self))
  
          self.context = context.RequestContext()
  
      @exception_wrapper.wrap_exception(service='compute', binary='nova-compute')
      def _raise_exception(self, context):
          raise test.TestingException
  
      def _generate_exception_notification(self):
          self.assertRaises(test.TestingException, self._raise_exception,
                            self.context)
  
      def test_wait_for_versioned_notifications(self):
          # Wait for a single notification which we emitted first
          self._generate_exception_notification()
  
          notifications = self.notifier.wait_for_versioned_notifications(
                  'compute.exception')
          self.assertEqual(1, len(notifications))
  
      def test_wait_for_versioned_notifications_fail(self):
          # Wait for a single notification which is never sent
          self.assertRaises(
              AssertionError,
              self.notifier.wait_for_versioned_notifications,
              'compute.exception', timeout=0.1)
  
      def test_wait_for_versioned_notifications_n(self):
          # Wait for 2 notifications which we emitted first
          self._generate_exception_notification()
          self._generate_exception_notification()
  
          notifications = self.notifier.wait_for_versioned_notifications(
                  'compute.exception', 2)
          self.assertEqual(2, len(notifications))
  
      def test_wait_for_versioned_notifications_n_fail(self):
          # Wait for 2 notifications when we only emitted one
          self._generate_exception_notification()
  
          self.assertRaises(
              AssertionError,
              self.notifier.wait_for_versioned_notifications,
              'compute.exception', 2, timeout=0.1)
  
      def test_wait_for_versioned_notifications_too_many(self):
          # Wait for a single notification when there are 2 in the queue
          self._generate_exception_notification()
          self._generate_exception_notification()
  
          notifications = self.notifier.wait_for_versioned_notifications(
                  'compute.exception')
          self.assertEqual(2, len(notifications))
  