text: """
  Tests for django.core.servers.
  """
  import errno
  import os
  import socket
  import sys
  from http.client import HTTPConnection, RemoteDisconnected
  from urllib.error import HTTPError
  from urllib.parse import urlencode
  from urllib.request import urlopen
  
  from django.test import LiveServerTestCase, override_settings
  
  from .models import Person
  
  TEST_ROOT = os.path.dirname(__file__)
  TEST_SETTINGS = {
      'MEDIA_URL': '/media/',
      'MEDIA_ROOT': os.path.join(TEST_ROOT, 'media'),
      'STATIC_URL': '/static/',
      'STATIC_ROOT': os.path.join(TEST_ROOT, 'static'),
  }
  
  
  @override_settings(ROOT_URLCONF='servers.urls', **TEST_SETTINGS)
  class LiveServerBase(LiveServerTestCase):
  
      available_apps = [
          'servers',
          'django.contrib.auth',
          'django.contrib.contenttypes',
          'django.contrib.sessions',
      ]
      fixtures = ['testdata.json']
  
      def urlopen(self, url):
          return urlopen(self.live_server_url + url)
  
  
  class LiveServerAddress(LiveServerBase):
  
      @classmethod
      def setUpClass(cls):
          super().setUpClass()
          # put it in a list to prevent descriptor lookups in test
          cls.live_server_url_test = [cls.live_server_url]
  
      def test_live_server_url_is_class_property(self):
          self.assertIsInstance(self.live_server_url_test[0], str)
          self.assertEqual(self.live_server_url_test[0], self.live_server_url)
  
  
  class LiveServerViews(LiveServerBase):
      def test_protocol(self):
          """Launched server serves with HTTP 1.1."""
          with self.urlopen('/example_view/') as f:
              self.assertEqual(f.version, 11)
  
      @override_settings(MIDDLEWARE=[])
      def test_closes_connection_without_content_length(self):
          """
          The server doesn't support keep-alive because Python's http.server
          module that it uses hangs if a Content-Length header isn't set (for
          example, if CommonMiddleware isn't enabled or if the response is a
          StreamingHttpResponse) (#28440 / https://bugs.python.org/issue31076).
          """
          conn = HTTPConnection(LiveServerViews.server_thread.host, LiveServerViews.server_thread.port, timeout=1)
          try:
              conn.request('GET', '/example_view/', headers={'Connection': 'keep-alive'})
              response = conn.getresponse().read()
              conn.request('GET', '/example_view/', headers={'Connection': 'close'})
              # macOS may give ConnectionResetError.
              with self.assertRaises((RemoteDisconnected, ConnectionResetError)):
                  try:
                      conn.getresponse()
                  except ConnectionAbortedError:
                      if sys.platform == 'win32':
                          self.skipTest('Ignore nondeterministic failure on Windows.')
          finally:
              conn.close()
          self.assertEqual(response, b'example view')
  
      def test_404(self):
          with self.assertRaises(HTTPError) as err:
              self.urlopen('/')
          err.exception.close()
          self.assertEqual(err.exception.code, 404, 'Expected 404 response')
  
      def test_view(self):
          with self.urlopen('/example_view/') as f:
              self.assertEqual(f.read(), b'example view')
  
      def test_static_files(self):
          with self.urlopen('/static/example_static_file.txt') as f:
              self.assertEqual(f.read().rstrip(b'\r\n'), b'example static file')
  
      def test_no_collectstatic_emulation(self):
          """
          LiveServerTestCase reports a 404 status code when HTTP client
          tries to access a static file that isn't explicitly put under
          STATIC_ROOT.
          """
          with self.assertRaises(HTTPError) as err:
              self.urlopen('/static/another_app/another_app_static_file.txt')
          err.exception.close()
          self.assertEqual(err.exception.code, 404, 'Expected 404 response')
  
      def test_media_files(self):
          with self.urlopen('/media/example_media_file.txt') as f:
              self.assertEqual(f.read().rstrip(b'\r\n'), b'example media file')
  
      def test_environ(self):
          with self.urlopen('/environ_view/?%s' % urlencode({'q': 'тест'})) as f:
              self.assertIn(b"QUERY_STRING: 'q=%D1%82%D0%B5%D1%81%D1%82'", f.read())
  
  
  class LiveServerDatabase(LiveServerBase):
  
      def test_fixtures_loaded(self):
          """
          Fixtures are properly loaded and visible to the live server thread.
          """
          with self.urlopen('/model_view/') as f:
              self.assertEqual(f.read().splitlines(), [b'jane', b'robert'])
  
      def test_database_writes(self):
          """
          Data written to the database by a view can be read.
          """
          with self.urlopen('/create_model_instance/'):
              pass
          self.assertQuerysetEqual(
              Person.objects.all().order_by('pk'),
              ['jane', 'robert', 'emily'],
              lambda b: b.name
          )
  
  
  class LiveServerPort(LiveServerBase):
  
      def test_port_bind(self):
          """
          Each LiveServerTestCase binds to a unique port or fails to start a
          server thread when run concurrently (#26011).
          """
          TestCase = type("TestCase", (LiveServerBase,), {})
          try:
              TestCase.setUpClass()
          except socket.error as e:
              if e.errno == errno.EADDRINUSE:
                  # We're out of ports, LiveServerTestCase correctly fails with
                  # a socket error.
                  return
              # Unexpected error.
              raise
          try:
              # We've acquired a port, ensure our server threads acquired
              # different addresses.
              self.assertNotEqual(
                  self.live_server_url, TestCase.live_server_url,
                  "Acquired duplicate server addresses for server threads: %s" % self.live_server_url
              )
          finally:
              if hasattr(TestCase, 'server_thread'):
                  TestCase.server_thread.terminate()
  
      def test_specified_port_bind(self):
          """LiveServerTestCase.port customizes the server's port."""
          TestCase = type(str('TestCase'), (LiveServerBase,), {})
          # Find an open port and tell TestCase to use it.
          s = socket.socket()
          s.bind(('', 0))
          TestCase.port = s.getsockname()[1]
          s.close()
          TestCase.setUpClass()
          try:
              self.assertEqual(
                  TestCase.port, TestCase.server_thread.port,
                  'Did not use specified port for LiveServerTestCase thread: %s' % TestCase.port
              )
          finally:
              if hasattr(TestCase, 'server_thread'):
                  TestCase.server_thread.terminate()
  
  
  class LiverServerThreadedTests(LiveServerBase):
      """If LiverServerTestCase isn't threaded, these tests will hang."""
  
      def test_view_calls_subview(self):
          url = '/subview_calling_view/?%s' % urlencode({'url': self.live_server_url})
          with self.urlopen(url) as f:
              self.assertEqual(f.read(), b'subview calling view: subview')
  
      def test_check_model_instance_from_subview(self):
          url = '/check_model_instance_from_subview/?%s' % urlencode({
              'url': self.live_server_url,
          })
          with self.urlopen(url) as f:
              self.assertIn(b'emily', f.read())
  