text: import sys
  
  from django.conf import settings
  from django.core.signals import got_request_exception
  from django.http import HttpResponse
  from django.template.response import TemplateResponse
  from django.template import Template
  from django.test import TestCase, override_settings
  
  
  class TestException(Exception):
      pass
  
  
  # A middleware base class that tracks which methods have been called
  class TestMiddleware(object):
      def __init__(self):
          self.process_request_called = False
          self.process_view_called = False
          self.process_response_called = False
          self.process_template_response_called = False
          self.process_exception_called = False
  
      def process_request(self, request):
          self.process_request_called = True
  
      def process_view(self, request, view_func, view_args, view_kwargs):
          self.process_view_called = True
  
      def process_template_response(self, request, response):
          self.process_template_response_called = True
          return response
  
      def process_response(self, request, response):
          self.process_response_called = True
          return response
  
      def process_exception(self, request, exception):
          self.process_exception_called = True
  
  
  # Middleware examples that do the right thing
  class RequestMiddleware(TestMiddleware):
      def process_request(self, request):
          super(RequestMiddleware, self).process_request(request)
          return HttpResponse('Request Middleware')
  
  
  class ViewMiddleware(TestMiddleware):
      def process_view(self, request, view_func, view_args, view_kwargs):
          super(ViewMiddleware, self).process_view(request, view_func, view_args, view_kwargs)
          return HttpResponse('View Middleware')
  
  
  class ResponseMiddleware(TestMiddleware):
      def process_response(self, request, response):
          super(ResponseMiddleware, self).process_response(request, response)
          return HttpResponse('Response Middleware')
  
  
  class TemplateResponseMiddleware(TestMiddleware):
      def process_template_response(self, request, response):
          super(TemplateResponseMiddleware, self).process_template_response(request, response)
          return TemplateResponse(request, Template('Template Response Middleware'))
  
  
  class ExceptionMiddleware(TestMiddleware):
      def process_exception(self, request, exception):
          super(ExceptionMiddleware, self).process_exception(request, exception)
          return HttpResponse('Exception Middleware')
  
  
  # Sample middlewares that raise exceptions
  class BadRequestMiddleware(TestMiddleware):
      def process_request(self, request):
          super(BadRequestMiddleware, self).process_request(request)
          raise TestException('Test Request Exception')
  
  
  class BadViewMiddleware(TestMiddleware):
      def process_view(self, request, view_func, view_args, view_kwargs):
          super(BadViewMiddleware, self).process_view(request, view_func, view_args, view_kwargs)
          raise TestException('Test View Exception')
  
  
  class BadTemplateResponseMiddleware(TestMiddleware):
      def process_template_response(self, request, response):
          super(BadTemplateResponseMiddleware, self).process_template_response(request, response)
          raise TestException('Test Template Response Exception')
  
  
  class BadResponseMiddleware(TestMiddleware):
      def process_response(self, request, response):
          super(BadResponseMiddleware, self).process_response(request, response)
          raise TestException('Test Response Exception')
  
  
  class BadExceptionMiddleware(TestMiddleware):
      def process_exception(self, request, exception):
          super(BadExceptionMiddleware, self).process_exception(request, exception)
          raise TestException('Test Exception Exception')
  
  
  class BaseMiddlewareExceptionTest(TestCase):
      urls = 'middleware_exceptions.urls'
  
      def setUp(self):
          self.exceptions = []
          got_request_exception.connect(self._on_request_exception)
          self.client.handler.load_middleware()
  
      def tearDown(self):
          got_request_exception.disconnect(self._on_request_exception)
          self.exceptions = []
  
      def _on_request_exception(self, sender, request, **kwargs):
          self.exceptions.append(sys.exc_info())
  
      def _add_middleware(self, middleware):
          self.client.handler._request_middleware.insert(0, middleware.process_request)
          self.client.handler._view_middleware.insert(0, middleware.process_view)
          self.client.handler._template_response_middleware.append(middleware.process_template_response)
          self.client.handler._response_middleware.append(middleware.process_response)
          self.client.handler._exception_middleware.append(middleware.process_exception)
  
      def assert_exceptions_handled(self, url, errors, extra_error=None):
          try:
              self.client.get(url)
          except TestException:
              # Test client intentionally re-raises any exceptions being raised
              # during request handling. Hence actual testing that exception was
              # properly handled is done by relying on got_request_exception
              # signal being sent.
              pass
          except Exception as e:
              if type(extra_error) != type(e):
                  self.fail("Unexpected exception: %s" % e)
          self.assertEqual(len(self.exceptions), len(errors))
          for i, error in enumerate(errors):
              exception, value, tb = self.exceptions[i]
              self.assertEqual(value.args, (error, ))
  
      def assert_middleware_usage(self, middleware, request, view, template_response, response, exception):
          self.assertEqual(middleware.process_request_called, request)
          self.assertEqual(middleware.process_view_called, view)
          self.assertEqual(middleware.process_template_response_called, template_response)
          self.assertEqual(middleware.process_response_called, response)
          self.assertEqual(middleware.process_exception_called, exception)
  
  
  class MiddlewareTests(BaseMiddlewareExceptionTest):
  
      def test_process_request_middleware(self):
          pre_middleware = TestMiddleware()
          middleware = RequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_middleware(self):
          pre_middleware = TestMiddleware()
          middleware = ViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_middleware(self):
          pre_middleware = TestMiddleware()
          middleware = ResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_template_response_middleware(self):
          pre_middleware = TestMiddleware()
          middleware = TemplateResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/template_response/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, True, True, False)
          self.assert_middleware_usage(middleware, True, True, True, True, False)
          self.assert_middleware_usage(post_middleware, True, True, True, True, False)
  
      def test_process_exception_middleware(self):
          pre_middleware = TestMiddleware()
          middleware = ExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_request_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          middleware = RequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          middleware = ViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_template_response_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          middleware = TemplateResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, True)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_response_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          middleware = ResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, True)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          middleware = ExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_request_middleware_exception(self):
          pre_middleware = TestMiddleware()
          middleware = RequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_middleware_exception(self):
          pre_middleware = TestMiddleware()
          middleware = ViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_middleware_exception(self):
          pre_middleware = TestMiddleware()
          middleware = ResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', ['Error in view'], Exception())
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, True)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_middleware_exception(self):
          pre_middleware = TestMiddleware()
          middleware = ExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_request_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          middleware = RequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          middleware = ViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          middleware = ResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [
              "The view middleware_exceptions.views.null_view didn't return an HttpResponse object. It returned None instead.",
          ],
              ValueError())
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_exception_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          middleware = ExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [
              "The view middleware_exceptions.views.null_view didn't return an HttpResponse object. It returned None instead."
          ],
              ValueError())
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_request_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          middleware = RequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          middleware = ViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          middleware = ResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, True)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          middleware = ExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_template_response_error(self):
          middleware = TestMiddleware()
          self._add_middleware(middleware)
          self.assert_exceptions_handled('/middleware_exceptions/template_response_error/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(middleware, True, True, True, True, False)
  
  
  class BadMiddlewareTests(BaseMiddlewareExceptionTest):
  
      def test_process_request_bad_middleware(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadRequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', ['Test Request Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_bad_middleware(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', ['Test View Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_template_response_bad_middleware(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadTemplateResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/template_response/', ['Test Template Response Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, True, True, False)
          self.assert_middleware_usage(post_middleware, True, True, True, True, False)
  
      def test_process_response_bad_middleware(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', ['Test Response Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, False, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_exception_bad_middleware(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/view/', [])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_request_bad_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadRequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', ['Test Request Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_bad_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', ['Test View Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_bad_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', ['Test Response Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, False, True)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_bad_middleware_not_found(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/not_found/', ['Test Exception Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_request_bad_middleware_exception(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadRequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', ['Test Request Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_bad_middleware_exception(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', ['Test View Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_bad_middleware_exception(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', ['Error in view', 'Test Response Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, False, True)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_bad_middleware_exception(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/error/', ['Test Exception Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_request_bad_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadRequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', ['Test Request Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_bad_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', ['Test View Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_bad_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [
              "The view middleware_exceptions.views.null_view didn't return an HttpResponse object. It returned None instead.",
              'Test Response Exception'
          ])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, False, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_exception_bad_middleware_null_view(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/null_view/', [
              "The view middleware_exceptions.views.null_view didn't return an HttpResponse object. It returned None instead."
          ],
              ValueError())
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, True, False, True, False)
  
      def test_process_request_bad_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadRequestMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', ['Test Request Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, False, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, False, False, True, False)
          self.assert_middleware_usage(post_middleware, False, False, False, True, False)
  
      def test_process_view_bad_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadViewMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', ['Test View Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, False)
          self.assert_middleware_usage(post_middleware, True, False, False, True, False)
  
      def test_process_response_bad_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadResponseMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', ['Test Response Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, False, True)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
      def test_process_exception_bad_middleware_permission_denied(self):
          pre_middleware = TestMiddleware()
          bad_middleware = BadExceptionMiddleware()
          post_middleware = TestMiddleware()
          self._add_middleware(post_middleware)
          self._add_middleware(bad_middleware)
          self._add_middleware(pre_middleware)
          self.assert_exceptions_handled('/middleware_exceptions/permission_denied/', ['Test Exception Exception'])
  
          # Check that the right middleware methods have been invoked
          self.assert_middleware_usage(pre_middleware, True, True, False, True, False)
          self.assert_middleware_usage(bad_middleware, True, True, False, True, True)
          self.assert_middleware_usage(post_middleware, True, True, False, True, True)
  
  
  _missing = object()
  
  
  class RootUrlconfTests(TestCase):
      urls = 'middleware_exceptions.urls'
  
      @override_settings(ROOT_URLCONF=None)
      def test_missing_root_urlconf(self):
          # Removing ROOT_URLCONF is safe, as override_settings will restore
          # the previously defined settings.
          del settings.ROOT_URLCONF
          self.assertRaises(AttributeError, self.client.get, "/middleware_exceptions/view/")
  