diff --git a/django/core/handlers/base.py b/django/core/handlers/base.py index ffc48a076a..010d5e35ee 100644 --- a/django/core/handlers/base.py +++ b/django/core/handlers/base.py @@ -134,6 +134,12 @@ class BaseHandler(object): if hasattr(response, 'render') and callable(response.render): for middleware_method in self._template_response_middleware: response = middleware_method(request, response) + # Complain if the template response middleware returned None (a common error). + if response is None: + raise ValueError( + "%s.process_template_response didn't return an " + "HttpResponse object. It returned None instead." + % (middleware_method.__self__.__class__.__name__)) response = response.render() except http.Http404 as e: @@ -202,6 +208,12 @@ class BaseHandler(object): # Apply response middleware, regardless of the response for middleware_method in self._response_middleware: response = middleware_method(request, response) + # Complain if the response middleware returned None (a common error). + if response is None: + raise ValueError( + "%s.process_response didn't return an " + "HttpResponse object. It returned None instead." + % (middleware_method.__self__.__class__.__name__)) response = self.apply_response_fixes(request, response) except: # Any exception should be gathered and handled signals.got_request_exception.send(sender=self.__class__, request=request) diff --git a/tests/middleware_exceptions/tests.py b/tests/middleware_exceptions/tests.py index 63f4fa7b70..473e726d8b 100644 --- a/tests/middleware_exceptions/tests.py +++ b/tests/middleware_exceptions/tests.py @@ -101,6 +101,17 @@ class BadExceptionMiddleware(TestMiddleware): raise TestException('Test Exception Exception') +# Sample middlewares that omit to return an HttpResonse +class NoTemplateResponseMiddleware(TestMiddleware): + def process_template_response(self, request, response): + super(NoTemplateResponseMiddleware, self).process_template_response(request, response) + + +class NoResponseMiddleware(TestMiddleware): + def process_response(self, request, response): + super(NoResponseMiddleware, self).process_response(request, response) + + @override_settings(ROOT_URLCONF='middleware_exceptions.urls') class BaseMiddlewareExceptionTest(TestCase): @@ -775,6 +786,39 @@ class BadMiddlewareTests(BaseMiddlewareExceptionTest): 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_response_no_response_middleware(self): + pre_middleware = TestMiddleware() + middleware = NoResponseMiddleware() + post_middleware = TestMiddleware() + self._add_middleware(post_middleware) + self._add_middleware(middleware) + self._add_middleware(pre_middleware) + self.assert_exceptions_handled('/middleware_exceptions/view/', [ + "NoResponseMiddleware.process_response 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, False, 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_no_response_middleware(self): + pre_middleware = TestMiddleware() + middleware = NoTemplateResponseMiddleware() + 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/', [ + "NoTemplateResponseMiddleware.process_template_response 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, True, True, False) + self.assert_middleware_usage(post_middleware, True, True, True, True, False) _missing = object()