Refs #26601 -- Improved backwards-compatibility of DEP 5 middleware exception handling.

3 files changed, 188 insertions, 88 deletions

diff --git a/tests/middleware_exceptions/middleware.py b/tests/middleware_exceptions/middleware.py
index 6871d9556e..690660fb53 100644
--- a/tests/middleware_exceptions/middleware.py
+++ b/tests/middleware_exceptions/middleware.py
@@ -1,10 +1,58 @@
 from __future__ import unicode_literals
 
-from django.http import HttpResponse
-from django.utils.deprecation import MiddlewareMixin
+from django.http import Http404, HttpResponse
+from django.template import engines
 
+log = []
 
-class ProcessExceptionMiddleware(MiddlewareMixin):
 
+class BaseMiddleware(object):
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        return self.get_response(request)
+
+
+class ProcessExceptionMiddleware(BaseMiddleware):
     def process_exception(self, request, exception):
         return HttpResponse('Exception caught')
+
+
+class ProcessExceptionLogMiddleware(BaseMiddleware):
+    def process_exception(self, request, exception):
+        log.append('process-exception')
+
+
+class ProcessExceptionExcMiddleware(BaseMiddleware):
+    def process_exception(self, request, exception):
+        raise Exception('from process-exception')
+
+
+class ProcessViewMiddleware(BaseMiddleware):
+    def process_view(self, request, view_func, view_args, view_kwargs):
+        return HttpResponse('Processed view %s' % view_func.__name__)
+
+
+class ProcessViewNoneMiddleware(BaseMiddleware):
+    def process_view(self, request, view_func, view_args, view_kwargs):
+        log.append('processed view %s' % view_func.__name__)
+        return None
+
+
+class TemplateResponseMiddleware(BaseMiddleware):
+    def process_template_response(self, request, response):
+        response.template_name = engines['django'].from_string('template-response middleware')
+        return response
+
+
+class LogMiddleware(BaseMiddleware):
+    def __call__(self, request):
+        response = self.get_response(request)
+        log.append((response.status_code, response.content))
+        return response
+
+
+class NotFoundMiddleware(BaseMiddleware):
+    def __call__(self, request):
+        raise Http404('not found')
diff --git a/tests/middleware_exceptions/test_legacy.py b/tests/middleware_exceptions/test_legacy.py
index 6aab3782d8..d59caa3882 100644
--- a/tests/middleware_exceptions/test_legacy.py
+++ b/tests/middleware_exceptions/test_legacy.py
@@ -1,15 +1,15 @@
 import sys
 
-from django.conf import settings
-from django.core.exceptions import MiddlewareNotUsed
 from django.core.signals import got_request_exception
 from django.http import HttpResponse
 from django.template import engines
 from django.template.response import TemplateResponse
-from django.test import RequestFactory, SimpleTestCase, override_settings
-from django.test.utils import ignore_warnings, patch_logger
+from django.test import SimpleTestCase, override_settings
+from django.test.utils import ignore_warnings
 from django.utils.deprecation import MiddlewareMixin, RemovedInDjango20Warning
 
+from .tests import MiddlewareNotUsedTests
+
 
 class TestException(Exception):
     pass
@@ -512,14 +512,6 @@ class MiddlewareTests(BaseMiddlewareExceptionTest):
         # Check that the right middleware methods have been invoked
         self.assert_middleware_usage(middleware, True, True, True, True, False)
 
-    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.ProcessExceptionMiddleware'])
-    def test_exception_in_render_passed_to_process_exception(self):
-        # Repopulate the list of middlewares since it's already been populated
-        # by setUp() before the MIDDLEWARE setting got overridden.
-        self.client.handler.load_middleware()
-        response = self.client.get('/middleware_exceptions/exception_in_render/')
-        self.assertEqual(response.content, b'Exception caught')
-
 
 class BadMiddlewareTests(BaseMiddlewareExceptionTest):
 
@@ -869,79 +861,6 @@ class BadMiddlewareTests(BaseMiddlewareExceptionTest):
         self.assert_middleware_usage(middleware, True, True, True, True, False)
         self.assert_middleware_usage(post_middleware, True, True, True, True, False)
 
-_missing = object()
-
-
-@override_settings(ROOT_URLCONF='middleware_exceptions.urls')
-class RootUrlconfTests(SimpleTestCase):
-
-    @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
-        with self.assertRaises(AttributeError):
-            self.client.get("/middleware_exceptions/view/")
-
-
-class MyMiddleware(object):
-
-    def __init__(self, get_response=None):
-        raise MiddlewareNotUsed
-
-    def process_request(self, request):
-        pass
-
-
-class MyMiddlewareWithExceptionMessage(object):
-
-    def __init__(self, get_response=None):
-        raise MiddlewareNotUsed('spam eggs')
-
-    def process_request(self, request):
-        pass
-
-
-@override_settings(
-    DEBUG=True,
-    ROOT_URLCONF='middleware_exceptions.urls',
-    MIDDLEWARE=['django.middleware.common.CommonMiddleware'],
-)
-class MiddlewareNotUsedTests(SimpleTestCase):
-
-    rf = RequestFactory()
-
-    def test_raise_exception(self):
-        request = self.rf.get('middleware_exceptions/view/')
-        with self.assertRaises(MiddlewareNotUsed):
-            MyMiddleware().process_request(request)
-
-    @override_settings(MIDDLEWARE=['middleware_exceptions.test_legacy.MyMiddleware'])
-    def test_log(self):
-        with patch_logger('django.request', 'debug') as calls:
-            self.client.get('/middleware_exceptions/view/')
-        self.assertEqual(len(calls), 1)
-        self.assertEqual(
-            calls[0],
-            "MiddlewareNotUsed: 'middleware_exceptions.test_legacy.MyMiddleware'"
-        )
-
-    @override_settings(MIDDLEWARE=['middleware_exceptions.test_legacy.MyMiddlewareWithExceptionMessage'])
-    def test_log_custom_message(self):
-        with patch_logger('django.request', 'debug') as calls:
-            self.client.get('/middleware_exceptions/view/')
-        self.assertEqual(len(calls), 1)
-        self.assertEqual(
-            calls[0],
-            "MiddlewareNotUsed('middleware_exceptions.test_legacy.MyMiddlewareWithExceptionMessage'): spam eggs"
-        )
-
-    @override_settings(DEBUG=False)
-    def test_do_not_log_when_debug_is_false(self):
-        with patch_logger('django.request', 'debug') as calls:
-            self.client.get('/middleware_exceptions/view/')
-        self.assertEqual(len(calls), 0)
-
 
 @ignore_warnings(category=RemovedInDjango20Warning)
 @override_settings(
diff --git a/tests/middleware_exceptions/tests.py b/tests/middleware_exceptions/tests.py
new file mode 100644
index 0000000000..f6a7e24e59
--- /dev/null
+++ b/tests/middleware_exceptions/tests.py
@@ -0,0 +1,133 @@
+from django.conf import settings
+from django.core.exceptions import MiddlewareNotUsed
+from django.test import RequestFactory, SimpleTestCase, override_settings
+from django.test.utils import patch_logger
+
+from . import middleware as mw
+
+
+@override_settings(ROOT_URLCONF='middleware_exceptions.urls')
+class MiddlewareTests(SimpleTestCase):
+    def tearDown(self):
+        mw.log = []
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.ProcessViewNoneMiddleware'])
+    def test_process_view_return_none(self):
+        response = self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(mw.log, ['processed view normal_view'])
+        self.assertEqual(response.content, b'OK')
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.ProcessViewMiddleware'])
+    def test_process_view_return_response(self):
+        response = self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(response.content, b'Processed view normal_view')
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.TemplateResponseMiddleware'])
+    def test_process_template_response(self):
+        response = self.client.get('/middleware_exceptions/template_response/')
+        self.assertEqual(response.content, b'template-response middleware')
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.LogMiddleware'])
+    def test_view_exception_converted_before_middleware(self):
+        response = self.client.get('/middleware_exceptions/permission_denied/')
+        self.assertEqual(mw.log, [(response.status_code, response.content)])
+        self.assertEqual(response.status_code, 403)
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.ProcessExceptionMiddleware'])
+    def test_view_exception_handled_by_process_exception(self):
+        response = self.client.get('/middleware_exceptions/error/')
+        self.assertEqual(response.content, b'Exception caught')
+
+    @override_settings(MIDDLEWARE=[
+        'middleware_exceptions.middleware.ProcessExceptionLogMiddleware',
+        'middleware_exceptions.middleware.ProcessExceptionMiddleware',
+    ])
+    def test_response_from_process_exception_short_circuits_remainder(self):
+        response = self.client.get('/middleware_exceptions/error/')
+        self.assertEqual(mw.log, [])
+        self.assertEqual(response.content, b'Exception caught')
+
+    @override_settings(MIDDLEWARE=[
+        'middleware_exceptions.middleware.LogMiddleware',
+        'middleware_exceptions.middleware.NotFoundMiddleware',
+    ])
+    def test_exception_in_middleware_converted_before_prior_middleware(self):
+        response = self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(mw.log, [(404, response.content)])
+        self.assertEqual(response.status_code, 404)
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.middleware.ProcessExceptionMiddleware'])
+    def test_exception_in_render_passed_to_process_exception(self):
+        response = self.client.get('/middleware_exceptions/exception_in_render/')
+        self.assertEqual(response.content, b'Exception caught')
+
+
+@override_settings(ROOT_URLCONF='middleware_exceptions.urls')
+class RootUrlconfTests(SimpleTestCase):
+
+    @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
+        with self.assertRaises(AttributeError):
+            self.client.get("/middleware_exceptions/view/")
+
+
+class MyMiddleware(object):
+
+    def __init__(self, get_response=None):
+        raise MiddlewareNotUsed
+
+    def process_request(self, request):
+        pass
+
+
+class MyMiddlewareWithExceptionMessage(object):
+
+    def __init__(self, get_response=None):
+        raise MiddlewareNotUsed('spam eggs')
+
+    def process_request(self, request):
+        pass
+
+
+@override_settings(
+    DEBUG=True,
+    ROOT_URLCONF='middleware_exceptions.urls',
+    MIDDLEWARE=['django.middleware.common.CommonMiddleware'],
+)
+class MiddlewareNotUsedTests(SimpleTestCase):
+
+    rf = RequestFactory()
+
+    def test_raise_exception(self):
+        request = self.rf.get('middleware_exceptions/view/')
+        with self.assertRaises(MiddlewareNotUsed):
+            MyMiddleware().process_request(request)
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.tests.MyMiddleware'])
+    def test_log(self):
+        with patch_logger('django.request', 'debug') as calls:
+            self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(len(calls), 1)
+        self.assertEqual(
+            calls[0],
+            "MiddlewareNotUsed: 'middleware_exceptions.tests.MyMiddleware'"
+        )
+
+    @override_settings(MIDDLEWARE=['middleware_exceptions.tests.MyMiddlewareWithExceptionMessage'])
+    def test_log_custom_message(self):
+        with patch_logger('django.request', 'debug') as calls:
+            self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(len(calls), 1)
+        self.assertEqual(
+            calls[0],
+            "MiddlewareNotUsed('middleware_exceptions.tests.MyMiddlewareWithExceptionMessage'): spam eggs"
+        )
+
+    @override_settings(DEBUG=False)
+    def test_do_not_log_when_debug_is_false(self):
+        with patch_logger('django.request', 'debug') as calls:
+            self.client.get('/middleware_exceptions/view/')
+        self.assertEqual(len(calls), 0)