Fix issues with RequestFactory used as Request.

* Centralize creation of quick request objects.
* Isolate caches to individual tests to prevent test ordering
  dependencies.

TNL-5811

openedx/core/djangoapps/course_groups/tests/test_partition_scheme.py

@@ -359,13 +359,15 @@ class TestMasqueradedGroup(StaffMasqueradeTestCase):
         }
         request = self._create_mock_json_request(
             self.test_user,
-            body=json.dumps(request_json),
+            data=request_json,
             session=self.session
         )
-        handle_ajax(request, unicode(self.course.id))
+        response = handle_ajax(request, unicode(self.course.id))
+        # pylint has issues analyzing this class (maybe due to circular imports?)
+        self.assertEquals(response.status_code, 200)  # pylint: disable=no-member
 
         # Now setup the masquerade for the test user
-        setup_masquerade(request, self.test_user, True)
+        setup_masquerade(request, self.course.id, True)
         scheme = self.user_partition.scheme
         self.assertEqual(
             scheme.get_group_for_user(self.course.id, self.test_user, self.user_partition),

openedx/core/djangoapps/safe_sessions/tests/test_middleware.py

@@ -14,23 +14,14 @@ from django.test.utils import override_settings
 from mock import patch
 from nose.plugins.attrib import attr
 
+from openedx.core.djangolib.testing.utils import get_mock_request
+
 from student.tests.factories import UserFactory
 
 from ..middleware import SafeSessionMiddleware, SafeCookieData
 from .test_utils import TestSafeSessionsLogMixin
 
 
-def create_mock_request():
-    """
-    Creates and returns a mock request object for testing.
-    """
-    request = RequestFactory()
-    request.COOKIES = {}
-    request.META = {}
-    request.path = '/'
-    return request
-
-
 @attr(shard=2)
 class TestSafeSessionProcessRequest(TestSafeSessionsLogMixin, TestCase):
     """
@@ -39,7 +30,7 @@ class TestSafeSessionProcessRequest(TestSafeSessionsLogMixin, TestCase):
     def setUp(self):
         super(TestSafeSessionProcessRequest, self).setUp()
         self.user = UserFactory.create()
-        self.request = create_mock_request()
+        self.request = get_mock_request()
 
     def assert_response(self, safe_cookie_data=None, success=True):
         """
@@ -141,7 +132,7 @@ class TestSafeSessionProcessResponse(TestSafeSessionsLogMixin, TestCase):
     def setUp(self):
         super(TestSafeSessionProcessResponse, self).setUp()
         self.user = UserFactory.create()
-        self.request = create_mock_request()
+        self.request = get_mock_request()
         self.request.session = {}
         self.client.response = HttpResponse()
         self.client.response.cookies = SimpleCookie()
@@ -245,7 +236,7 @@ class TestSafeSessionMiddleware(TestSafeSessionsLogMixin, TestCase):
     def setUp(self):
         super(TestSafeSessionMiddleware, self).setUp()
         self.user = UserFactory.create()
-        self.request = create_mock_request()
+        self.request = get_mock_request()
         self.client.response = HttpResponse()
         self.client.response.cookies = SimpleCookie()
 

openedx/core/djangoapps/user_api/preferences/tests/test_api.py

@@ -11,10 +11,10 @@ from pytz import common_timezones, utc
 
 from django.conf import settings
 from django.contrib.auth.models import User
-from django.test import TestCase
 from django.test.utils import override_settings
 from dateutil.parser import parse as parse_datetime
 
+from openedx.core.djangolib.testing.utils import CacheIsolationTestCase
 from openedx.core.lib.time_zone_utils import get_display_time_zone
 from student.tests.factories import UserFactory
 
@@ -43,7 +43,7 @@ from ...preferences.api import (
 
 @attr(shard=2)
 @unittest.skipUnless(settings.ROOT_URLCONF == 'lms.urls', 'Account APIs are only supported in LMS')
-class TestPreferenceAPI(TestCase):
+class TestPreferenceAPI(CacheIsolationTestCase):
     """
     These tests specifically cover the parts of the API methods that are not covered by test_views.py.
     This includes the specific types of error raised, and default behavior when optional arguments
@@ -441,7 +441,7 @@ class UpdateEmailOptInTests(ModuleStoreTestCase):
 
 
 @ddt.ddt
-class CountryTimeZoneTest(TestCase):
+class CountryTimeZoneTest(CacheIsolationTestCase):
     """
     Test cases to validate country code api functionality
     """

openedx/core/djangolib/testing/tests/test_utils.py

@@ -0,0 +1,29 @@
+"""
+Test that testing utils do what they say.
+"""
+from django.contrib.auth import get_user_model
+from django.contrib.auth.models import AnonymousUser
+from django.http.request import HttpRequest
+from django.test import TestCase
+
+from ..utils import get_mock_request
+
+USER_MODEL = get_user_model()
+
+
+class TestGetMockRequest(TestCase):
+    """
+    Validate the behavior of get_mock_request
+    """
+    def test_mock_request_is_request(self):
+        request = get_mock_request(USER_MODEL())
+        self.assertIsInstance(request, HttpRequest)
+
+    def test_user_is_attached_to_mock_request(self):
+        user = USER_MODEL()
+        request = get_mock_request(user)
+        self.assertIs(request.user, user)
+
+    def test_mock_request_without_user(self):
+        request = get_mock_request()
+        self.assertIsInstance(request.user, AnonymousUser)

openedx/core/djangolib/testing/utils.py

@@ -10,9 +10,11 @@ Utility classes for testing django applications.
 
 import copy
 
+import crum
 from django import db
+from django.contrib.auth.models import AnonymousUser
 from django.core.cache import caches
-from django.test import TestCase, override_settings
+from django.test import RequestFactory, TestCase, override_settings
 from django.conf import settings
 from django.contrib import sites
 
@@ -158,3 +160,18 @@ class NoseDatabaseIsolation(Plugin):
         """
         for db_ in db.connections.all():
             db_.close()
+
+
+def get_mock_request(user=None):
+    """
+    Create a request object for the user, if specified.
+    """
+    request = RequestFactory().get('/')
+    if user is not None:
+        request.user = user
+    else:
+        request.user = AnonymousUser()
+    request.is_secure = lambda: True
+    request.get_host = lambda: "edx.org"
+    crum.set_current_request(request)
+    return request