text: # Copyright 2012 OpenStack Foundation
  # All Rights Reserved.
  #
  #    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 testtools
  
  from neutron.api.v2 import attributes
  from neutron.db import api as db_api
  # Import all data models
  from neutron.db.migration.models import head  # noqa
  from neutron.db import model_base
  from neutron.tests import base
  from neutron import wsgi
  
  
  class ExpectedException(testtools.ExpectedException):
      def __enter__(self):
          return self
  
      def __exit__(self, exc_type, exc_value, traceback):
          if super(ExpectedException, self).__exit__(exc_type,
                                                     exc_value,
                                                     traceback):
              self.exception = exc_value
              return True
          return False
  
  
  def create_request(path, body, content_type, method='GET',
                     query_string=None, context=None):
      if query_string:
          url = "%s?%s" % (path, query_string)
      else:
          url = path
      req = wsgi.Request.blank(url)
      req.method = method
      req.headers = {}
      req.headers['Accept'] = content_type
      req.body = body
      if context:
          req.environ['neutron.context'] = context
      return req
  
  
  class SqlTestCase(base.BaseTestCase):
  
      # flag to indicate that the models have been loaded
      _TABLES_ESTABLISHED = False
  
      def setUp(self):
          super(SqlTestCase, self).setUp()
          # Register all data models
          engine = db_api.get_engine()
          if not SqlTestCase._TABLES_ESTABLISHED:
              model_base.BASEV2.metadata.create_all(engine)
              SqlTestCase._TABLES_ESTABLISHED = True
  
          def clear_tables():
              with engine.begin() as conn:
                  for table in reversed(
                          model_base.BASEV2.metadata.sorted_tables):
                      conn.execute(table.delete())
  
          self.addCleanup(clear_tables)
  
  
  class WebTestCase(SqlTestCase):
      fmt = 'json'
  
      def setUp(self):
          super(WebTestCase, self).setUp()
          json_deserializer = wsgi.JSONDeserializer()
          xml_deserializer = wsgi.XMLDeserializer(
              attributes.get_attr_metadata())
          self._deserializers = {
              'application/json': json_deserializer,
              'application/xml': xml_deserializer,
          }
  
      def deserialize(self, response):
          ctype = 'application/%s' % self.fmt
          data = self._deserializers[ctype].deserialize(response.body)['body']
          return data
  
      def serialize(self, data):
          ctype = 'application/%s' % self.fmt
          result = wsgi.Serializer(
              attributes.get_attr_metadata()).serialize(data, ctype)
          return result
  
  
  class SubDictMatch(object):
  
      def __init__(self, sub_dict):
          self.sub_dict = sub_dict
  
      def __eq__(self, super_dict):
          return all(item in super_dict.items()
                     for item in self.sub_dict.items())
  