unit test

test/test_locked_sched.py

@@ -298,14 +298,17 @@ def test_get_task_id_and_duration_for_project_user_missing(self):
 
     @with_context
     @patch('pybossa.sched.task_repo.get_task')
-    def get_task_id_and_duration_for_project_user_invalid_task_id(self, get_task):
+    def test_get_task_id_and_duration_for_project_user_invalid_task_id(self, get_task):
         user = UserFactory.create()
         project = ProjectFactory.create(owner=user, short_name='egil', name='egil',
                   description='egil')
         task = TaskFactory.create_batch(1, project=project, n_answers=1)[0]
         limit = 1
         timeout = 100
         acquire_locks(task.id, user.id, limit, timeout)
+
+        # Simulate invalid task.
+        get_task.return_value =  None
         task_id, seconds = get_task_id_and_duration_for_project_user(project.id, user.id)
 
         assert task_id is None