Added test to simulate an error I had where an imported reference failed...

rest_framework/request.py

@@ -12,11 +12,13 @@
 from django.conf import settings
 from django.http import QueryDict
 from django.http.multipartparser import parse_header
+from django.utils import six
 from django.utils.datastructures import MultiValueDict
 from rest_framework import HTTP_HEADER_ENCODING
 from rest_framework import exceptions
 from rest_framework.compat import BytesIO
 from rest_framework.settings import api_settings
+import sys
 
 
 def is_form_media_type(media_type):
@@ -223,7 +225,10 @@ def user(self):
         by the authentication classes provided to the request.
         """
         if not hasattr(self, '_user'):
-            self._authenticate()
+            try:
+                self._authenticate()
+            except AttributeError as error:
+                six.reraise(RuntimeError, "AttributeError: " + str(error), sys.exc_info()[2])
         return self._user
 
     @user.setter

tests/test_request.py

@@ -333,6 +333,28 @@ def test_user_can_login(self):
         login(self.request, self.user)
         self.assertEqual(self.request.user, self.user)
 
+    def test_calling_user_fails_when_attribute_error_is_raised(self):
+        """
+        This proves that when an AttributeError is raised inside of the request.user
+        property, that we can handle this and report the true, underlying error.
+        """
+        class AuthRaisesAttributeError(object):
+            def authenticate(self, request):
+                import rest_framework
+                rest_framework.MISSPELLED_NAME_THAT_DOESNT_EXIST
+
+        self.request = Request(factory.get('/'), authenticators=(AuthRaisesAttributeError(),))
+        SessionMiddleware().process_request(self.request)
+
+        login(self.request, self.user)
+        error_seen = None
+        try:
+            self.request.user
+        except RuntimeError as error:
+            error_seen = error
+
+        self.assertEqual("AttributeError: 'module' object has no attribute 'MISSPELLED_NAME_THAT_DOESNT_EXIST'", error_seen.message)
+
     def test_user_can_logout(self):
         self.request.user = self.user
         self.assertFalse(self.request.user.is_anonymous())