Allow Waffle flags to work when outside a request context

lms/djangoapps/courseware/tests/test_course_tools.py

@@ -1,3 +1,8 @@
+"""
+Unit tests for course tools.
+"""
+
+import crum
 import datetime
 
 from mock import patch
@@ -59,6 +64,7 @@ class VerifiedUpgradeToolTest(SharedModuleStoreTestCase):
         )
         self.request = RequestFactory().request()
         self.request.user = self.enrollment.user
+        crum.set_current_request(self.request)
 
     def test_tool_visible(self):
         self.assertTrue(VerifiedUpgradeTool().is_enabled(self.request, self.course.id))

openedx/core/djangoapps/waffle_utils/__init__.py

@@ -45,6 +45,7 @@ To test WaffleSwitchNamespace, use the provided context managers.  For example:
         ...
 
 """
+import crum
 import logging
 from abc import ABCMeta
 from contextlib import contextmanager
@@ -54,7 +55,6 @@ from opaque_keys.edx.keys import CourseKey
 from waffle import flag_is_active, switch_is_active
 
 from request_cache import get_cache as get_request_cache
-from request_cache import get_request
 
 log = logging.getLogger(__name__)
 
@@ -256,7 +256,17 @@ class WaffleFlagNamespace(WaffleNamespace):
                         value = flag_undefined_default
 
                 if value is None:
-                    value = flag_is_active(get_request(), namespaced_flag_name)
+                    request = crum.get_current_request()
+                    if request:
+                        value = flag_is_active(request, namespaced_flag_name)
+                    else:
+                        log.warn(u"%sFlag '%s' accessed without a request", self.log_prefix, namespaced_flag_name)
+                        # Return the default value if not in a request context.
+                        # Note: this skips the cache as the value might be different
+                        # in a normal request context. This case seems to occur when
+                        # a page redirects to a 404. In this case, we'll just return
+                        # the default value.
+                        return bool(flag_undefined_default)
 
                 self._cached_flags[namespaced_flag_name] = value
         return value

openedx/core/djangoapps/waffle_utils/tests/test_init.py

@@ -1,8 +1,10 @@
 """
 Tests for waffle utils features.
 """
+import crum
 import ddt
 from django.test import TestCase
+from django.test.client import RequestFactory
 from mock import patch
 from opaque_keys.edx.keys import CourseKey
 from request_cache.middleware import RequestCache
@@ -27,6 +29,12 @@ class TestCourseWaffleFlag(TestCase):
     TEST_NAMESPACE = WaffleFlagNamespace(NAMESPACE_NAME)
     TEST_COURSE_FLAG = CourseWaffleFlag(TEST_NAMESPACE, FLAG_NAME)
 
+    def setUp(self):
+        super(TestCourseWaffleFlag, self).setUp()
+        request = RequestFactory().request()
+        crum.set_current_request(request)
+        RequestCache.clear_request_cache()
+
     @ddt.data(
         {'course_override': WaffleFlagCourseOverrideModel.ALL_CHOICES.on, 'waffle_enabled': False, 'result': True},
         {'course_override': WaffleFlagCourseOverrideModel.ALL_CHOICES.off, 'waffle_enabled': True, 'result': False},
@@ -38,8 +46,6 @@ class TestCourseWaffleFlag(TestCase):
         Tests various combinations of a flag being set in waffle and overridden
         for a course.
         """
-        RequestCache.clear_request_cache()
-
         with patch.object(WaffleFlagCourseOverrideModel, 'override_value', return_value=data['course_override']):
             with override_flag(self.NAMESPACED_FLAG_NAME, active=data['waffle_enabled']):
                 # check twice to test that the result is properly cached
@@ -70,8 +76,6 @@ class TestCourseWaffleFlag(TestCase):
         """
         Test flag with various defaults provided for undefined waffle flags.
         """
-        RequestCache.clear_request_cache()
-
         test_course_flag = CourseWaffleFlag(
             self.TEST_NAMESPACE,
             self.FLAG_NAME,
@@ -91,3 +95,20 @@ class TestCourseWaffleFlag(TestCase):
                 self.NAMESPACED_FLAG_NAME,
                 self.TEST_COURSE_KEY
             )
+
+    @ddt.data(
+        {'flag_undefined_default': None, 'result': False},
+        {'flag_undefined_default': False, 'result': False},
+        {'flag_undefined_default': True, 'result': True},
+    )
+    def test_without_request(self, data):
+        """
+        Test the flag behavior when outside a request context.
+        """
+        crum.set_current_request(None)
+        test_course_flag = CourseWaffleFlag(
+            self.TEST_NAMESPACE,
+            self.FLAG_NAME,
+            flag_undefined_default=data['flag_undefined_default']
+        )
+        self.assertEqual(test_course_flag.is_enabled(self.TEST_COURSE_KEY), data['result'])

openedx/core/djangoapps/waffle_utils/tests/test_testutils.py

@@ -1,7 +1,11 @@
 """
 Tests for waffle utils test utilities.
 """
+
+import crum
+
 from django.test import TestCase
+from django.test.client import RequestFactory
 from opaque_keys.edx.keys import CourseKey
 
 from request_cache.middleware import RequestCache
@@ -25,6 +29,8 @@ class OverrideWaffleFlagTests(TestCase):
 
     def setUp(self):
         super(OverrideWaffleFlagTests, self).setUp()
+        request = RequestFactory().request()
+        crum.set_current_request(request)
         RequestCache.clear_request_cache()
 
     @override_waffle_flag(TEST_COURSE_FLAG, True)