fix tests

common/djangoapps/track/tests/test_views.py

 # pylint: disable=missing-docstring,maybe-no-member
 
-from datetime import datetime
-
-from mock import patch
-from mock import sentinel
-from pytz import UTC
+from track import views
+from mock import patch, sentinel
+from freezegun import freeze_time
 
 from django.test import TestCase
 from django.test.client import RequestFactory
 
-from track import views
+from datetime import datetime
+expected_time = datetime(2013, 10, 3, 8, 24, 55)
 
 
 class TestTrackViews(TestCase):
@@ -21,12 +20,6 @@ class TestTrackViews(TestCase):
         self.mock_tracker = patcher.start()
         self.addCleanup(patcher.stop)
 
-        self._expected_timestamp = datetime.now(UTC)
-        self._datetime_patcher = patch('track.views.datetime')
-        self.addCleanup(self._datetime_patcher.stop)
-        mock_datetime_mod = self._datetime_patcher.start()
-        mock_datetime_mod.datetime.now.return_value = self._expected_timestamp  # pylint: disable=maybe-no-member
-
         self.path_with_course = '/courses/foo/bar/baz/xmod/'
         self.url_with_course = 'http://www.edx.org' + self.path_with_course
 
@@ -34,6 +27,7 @@ class TestTrackViews(TestCase):
             sentinel.key: sentinel.value
         }
 
+    @freeze_time(expected_time)
     def test_user_track(self):
         request = self.request_factory.get('/event', {
             'page': self.url_with_course,
@@ -51,7 +45,7 @@ class TestTrackViews(TestCase):
             'event': '{}',
             'agent': '',
             'page': self.url_with_course,
-            'time': self._expected_timestamp,
+            'time': expected_time,
             'host': 'testserver',
             'context': {
                 'course_id': 'foo/bar/baz',
@@ -60,6 +54,7 @@ class TestTrackViews(TestCase):
         }
         self.mock_tracker.send.assert_called_once_with(expected_event)
 
+    @freeze_time(expected_time)
     def test_server_track(self):
         request = self.request_factory.get(self.path_with_course)
         views.server_track(request, str(sentinel.event_type), '{}')
@@ -72,12 +67,13 @@ class TestTrackViews(TestCase):
             'event': '{}',
             'agent': '',
             'page': None,
-            'time': self._expected_timestamp,
+            'time': expected_time,
             'host': 'testserver',
             'context': {},
         }
         self.mock_tracker.send.assert_called_once_with(expected_event)
 
+    @freeze_time(expected_time)
     def test_server_track_with_no_request(self):
         request = None
         views.server_track(request, str(sentinel.event_type), '{}')
@@ -90,12 +86,13 @@ class TestTrackViews(TestCase):
             'event': '{}',
             'agent': '',
             'page': None,
-            'time': self._expected_timestamp,
+            'time': expected_time,
             'host': '',
             'context': {},
         }
         self.mock_tracker.send.assert_called_once_with(expected_event)
 
+    @freeze_time(expected_time)
     def test_task_track(self):
         request_info = {
             'username': 'anonymous',
@@ -120,7 +117,7 @@ class TestTrackViews(TestCase):
             'event': expected_event_data,
             'agent': 'agent',
             'page': None,
-            'time': self._expected_timestamp,
+            'time': expected_time,
             'host': 'testserver',
             'context': {
                 'course_id': '',