Add support for custom `task` location or command

[etc/taskwarrior.git] / tasklib / tests.py

diff --git a/tasklib/tests.py b/tasklib/tests.py
index a77058ab13c59a96f8f3a7c909b7082c14704209..6cba1fc6279a52410c5a5ec78f8764be08a8cf88 100644 (file)
--- a/tasklib/tests.py
+++ b/tasklib/tests.py
@@ -12,7 +12,7 @@ import tempfile
 import unittest
 
 from .backends import TaskWarrior
 import unittest
 
 from .backends import TaskWarrior

-from .task import Task, ReadOnlyDictView, TaskQuerySet
+from .task import Task, ReadOnlyDictView

 from .lazy import LazyUUIDTask, LazyUUIDTaskSet
 from .serializing import DATE_FORMAT, local_zone
 
 from .lazy import LazyUUIDTask, LazyUUIDTaskSet
 from .serializing import DATE_FORMAT, local_zone
 


@@ -40,62 +40,123 @@ TASK_STANDARD_ATTRS = (
     'annotations',
 )
 
     'annotations',
 )
 

-total_seconds_2_6 = lambda x: x.microseconds / 1e6 + x.seconds + x.days * 24 * 3600
+
+def total_seconds_2_6(x):
+    return x.microseconds / 1e6 + x.seconds + x.days * 24 * 3600

 
 
 class TasklibTest(unittest.TestCase):
 
 
 
 class TasklibTest(unittest.TestCase):
 

+    def get_taskwarrior(self, **kwargs):
+        tw_kwargs = dict(
+            data_location=self.tmp,
+            taskrc_location='/',
+        )
+        tw_kwargs.update(kwargs)
+        return TaskWarrior(**tw_kwargs)
+

     def setUp(self):
         self.tmp = tempfile.mkdtemp(dir='.')
     def setUp(self):
         self.tmp = tempfile.mkdtemp(dir='.')

-        self.tw = TaskWarrior(data_location=self.tmp, taskrc_location='/')
+        self.tw = self.get_taskwarrior()

 
     def tearDown(self):
         shutil.rmtree(self.tmp)
 
 
 
     def tearDown(self):
         shutil.rmtree(self.tmp)
 
 

+class TaskWarriorTest(TasklibTest):
+
+    def test_custom_command(self):
+        # ensure that a custom command which contains multiple parts
+        # is properly split up
+        tw = self.get_taskwarrior(task_command='wsl task')
+        self.assertEqual(tw._get_task_command(), ['wsl', 'task'])
+
+

 class TaskFilterTest(TasklibTest):
 
     def test_all_empty(self):
         self.assertEqual(len(self.tw.tasks.all()), 0)
 
     def test_all_non_empty(self):
 class TaskFilterTest(TasklibTest):
 
     def test_all_empty(self):
         self.assertEqual(len(self.tw.tasks.all()), 0)
 
     def test_all_non_empty(self):

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

         self.assertEqual(len(self.tw.tasks.all()), 1)
         self.assertEqual(self.tw.tasks.all()[0]['description'], 'test task')
         self.assertEqual(self.tw.tasks.all()[0]['status'], 'pending')
 
     def test_pending_non_empty(self):
         self.assertEqual(len(self.tw.tasks.all()), 1)
         self.assertEqual(self.tw.tasks.all()[0]['description'], 'test task')
         self.assertEqual(self.tw.tasks.all()[0]['status'], 'pending')
 
     def test_pending_non_empty(self):

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

         self.assertEqual(len(self.tw.tasks.pending()), 1)
         self.assertEqual(len(self.tw.tasks.pending()), 1)

-        self.assertEqual(self.tw.tasks.pending()[0]['description'],
-                         'test task')
+        self.assertEqual(
+            self.tw.tasks.pending()[0]['description'],
+            'test task',
+        )

         self.assertEqual(self.tw.tasks.pending()[0]['status'], 'pending')
 
     def test_completed_empty(self):
         self.assertEqual(self.tw.tasks.pending()[0]['status'], 'pending')
 
     def test_completed_empty(self):

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

         self.assertEqual(len(self.tw.tasks.completed()), 0)
 
     def test_completed_non_empty(self):
         self.assertEqual(len(self.tw.tasks.completed()), 0)
 
     def test_completed_non_empty(self):

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

         self.assertEqual(len(self.tw.tasks.completed()), 0)
         self.tw.tasks.all()[0].done()
         self.assertEqual(len(self.tw.tasks.completed()), 1)
 
         self.assertEqual(len(self.tw.tasks.completed()), 0)
         self.tw.tasks.all()[0].done()
         self.assertEqual(len(self.tw.tasks.completed()), 1)
 

+    def test_deleted_empty(self):
+        Task(self.tw, description='test task').save()
+        self.assertEqual(len(self.tw.tasks.deleted()), 0)
+
+    def test_deleted_non_empty(self):
+        Task(self.tw, description='test task').save()
+        self.assertEqual(len(self.tw.tasks.deleted()), 0)
+        self.tw.tasks.all()[0].delete()
+        self.assertEqual(len(self.tw.tasks.deleted()), 1)
+
+    def test_waiting_empty(self):
+        Task(self.tw, description='test task').save()
+        self.assertEqual(len(self.tw.tasks.waiting()), 0)
+
+    def test_waiting_non_empty(self):
+        Task(self.tw, description='test task').save()
+        self.assertEqual(len(self.tw.tasks.waiting()), 0)
+
+        t = self.tw.tasks.all()[0]
+        t['wait'] = datetime.datetime.now() + datetime.timedelta(days=1)
+        t.save()
+
+        self.assertEqual(len(self.tw.tasks.waiting()), 1)
+
+    def test_recurring_empty(self):
+        Task(self.tw, description='test task').save()
+        self.assertEqual(len(self.tw.tasks.recurring()), 0)
+
+    def test_recurring_non_empty(self):
+        Task(
+            self.tw,
+            description='test task',
+            recur='daily',
+            due=datetime.datetime.now(),
+        ).save()
+        self.assertEqual(len(self.tw.tasks.recurring()), 1)
+

     def test_filtering_by_attribute(self):
     def test_filtering_by_attribute(self):

-        Task(self.tw, description="no priority task").save()
-        Task(self.tw, priority="H", description="high priority task").save()
+        Task(self.tw, description='no priority task').save()
+        Task(self.tw, priority='H', description='high priority task').save()

         self.assertEqual(len(self.tw.tasks.all()), 2)
 
         # Assert that the correct number of tasks is returned
         self.assertEqual(len(self.tw.tasks.all()), 2)
 
         # Assert that the correct number of tasks is returned

-        self.assertEqual(len(self.tw.tasks.filter(priority="H")), 1)
+        self.assertEqual(len(self.tw.tasks.filter(priority='H')), 1)

 
         # Assert that the correct tasks are returned
 
         # Assert that the correct tasks are returned

-        high_priority_task = self.tw.tasks.get(priority="H")
-        self.assertEqual(high_priority_task['description'], "high priority task")
+        high_priority_task = self.tw.tasks.get(priority='H')
+        self.assertEqual(
+            high_priority_task['description'],
+            'high priority task',
+        )

 
     def test_filtering_by_empty_attribute(self):
 
     def test_filtering_by_empty_attribute(self):

-        Task(self.tw, description="no priority task").save()
-        Task(self.tw, priority="H", description="high priority task").save()
+        Task(self.tw, description='no priority task').save()
+        Task(self.tw, priority='H', description='high priority task').save()

         self.assertEqual(len(self.tw.tasks.all()), 2)
 
         # Assert that the correct number of tasks is returned
         self.assertEqual(len(self.tw.tasks.all()), 2)
 
         # Assert that the correct number of tasks is returned


@@ -103,69 +164,69 @@ class TaskFilterTest(TasklibTest):
 
         # Assert that the correct tasks are returned
         no_priority_task = self.tw.tasks.get(priority=None)
 
         # Assert that the correct tasks are returned
         no_priority_task = self.tw.tasks.get(priority=None)

-        self.assertEqual(no_priority_task['description'], "no priority task")
+        self.assertEqual(no_priority_task['description'], 'no priority task')

 
     def test_filter_for_task_with_space_in_descripition(self):
 
     def test_filter_for_task_with_space_in_descripition(self):

-        task = Task(self.tw, description="test task")
+        task = Task(self.tw, description='test task')

         task.save()
 
         task.save()
 

-        filtered_task = self.tw.tasks.get(description="test task")
-        self.assertEqual(filtered_task['description'], "test task")
+        filtered_task = self.tw.tasks.get(description='test task')
+        self.assertEqual(filtered_task['description'], 'test task')

 
     def test_filter_for_task_without_space_in_descripition(self):
 
     def test_filter_for_task_without_space_in_descripition(self):

-        task = Task(self.tw, description="test")
+        task = Task(self.tw, description='test')

         task.save()
 
         task.save()
 

-        filtered_task = self.tw.tasks.get(description="test")
-        self.assertEqual(filtered_task['description'], "test")
+        filtered_task = self.tw.tasks.get(description='test')
+        self.assertEqual(filtered_task['description'], 'test')

 
     def test_filter_for_task_with_space_in_project(self):
 
     def test_filter_for_task_with_space_in_project(self):

-        task = Task(self.tw, description="test", project="random project")
+        task = Task(self.tw, description='test', project='random project')

         task.save()
 
         task.save()
 

-        filtered_task = self.tw.tasks.get(project="random project")
-        self.assertEqual(filtered_task['project'], "random project")
+        filtered_task = self.tw.tasks.get(project='random project')
+        self.assertEqual(filtered_task['project'], 'random project')

 
     def test_filter_for_task_without_space_in_project(self):
 
     def test_filter_for_task_without_space_in_project(self):

-        task = Task(self.tw, description="test", project="random")
+        task = Task(self.tw, description='test', project='random')

         task.save()
 
         task.save()
 

-        filtered_task = self.tw.tasks.get(project="random")
-        self.assertEqual(filtered_task['project'], "random")
+        filtered_task = self.tw.tasks.get(project='random')
+        self.assertEqual(filtered_task['project'], 'random')

 
     def test_filter_with_empty_uuid(self):
         self.assertRaises(ValueError, lambda: self.tw.tasks.get(uuid=''))
 
     def test_filter_dummy_by_status(self):
 
     def test_filter_with_empty_uuid(self):
         self.assertRaises(ValueError, lambda: self.tw.tasks.get(uuid=''))
 
     def test_filter_dummy_by_status(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(status=t['status'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_uuid(self):
         t.save()
 
         tasks = self.tw.tasks.filter(status=t['status'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_uuid(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(uuid=t['uuid'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_entry(self):
         t.save()
 
         tasks = self.tw.tasks.filter(uuid=t['uuid'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_entry(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(entry=t['entry'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_description(self):
         t.save()
 
         tasks = self.tw.tasks.filter(entry=t['entry'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_description(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(description=t['description'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_start(self):
         t.save()
 
         tasks = self.tw.tasks.filter(description=t['description'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_start(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
         t.start()
 
         t.save()
         t.start()
 


@@ -173,7 +234,7 @@ class TaskFilterTest(TasklibTest):
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_end(self):
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_end(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
         t.done()
 
         t.save()
         t.done()
 


@@ -181,14 +242,14 @@ class TaskFilterTest(TasklibTest):
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_due(self):
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_due(self):

-        t = Task(self.tw, description="test", due=datetime.datetime.now())
+        t = Task(self.tw, description='test', due=datetime.datetime.now())

         t.save()
 
         tasks = self.tw.tasks.filter(due=t['due'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_until(self):
         t.save()
 
         tasks = self.tw.tasks.filter(due=t['due'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_until(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(until=t['until'])
         t.save()
 
         tasks = self.tw.tasks.filter(until=t['until'])


@@ -205,35 +266,35 @@ class TaskFilterTest(TasklibTest):
             else:
                 return
 
             else:
                 return
 

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(modified=t['modified'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_scheduled(self):
         t.save()
 
         tasks = self.tw.tasks.filter(modified=t['modified'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_scheduled(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         tasks = self.tw.tasks.filter(scheduled=t['scheduled'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_tags(self):
         t.save()
 
         tasks = self.tw.tasks.filter(scheduled=t['scheduled'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_tags(self):

-        t = Task(self.tw, description="test", tags=["home"])
+        t = Task(self.tw, description='test', tags=['home'])

         t.save()
 
         tasks = self.tw.tasks.filter(tags=t['tags'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_projects(self):
         t.save()
 
         tasks = self.tw.tasks.filter(tags=t['tags'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_dummy_by_projects(self):

-        t = Task(self.tw, description="test", project="random")
+        t = Task(self.tw, description='test', project='random')

         t.save()
 
         tasks = self.tw.tasks.filter(project=t['project'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_by_priority(self):
         t.save()
 
         tasks = self.tw.tasks.filter(project=t['project'])
         self.assertEqual(list(tasks), [t])
 
     def test_filter_by_priority(self):

-        t = Task(self.tw, description="test", priority="H")
+        t = Task(self.tw, description='test', priority='H')

         t.save()
 
         tasks = self.tw.tasks.filter(priority=t['priority'])
         t.save()
 
         tasks = self.tw.tasks.filter(priority=t['priority'])


@@ -244,71 +305,83 @@ class TaskTest(TasklibTest):
 
     def test_create_unsaved_task(self):
         # Make sure a new task is not saved unless explicitly called for
 
     def test_create_unsaved_task(self):
         # Make sure a new task is not saved unless explicitly called for

-        t = Task(self.tw, description="test task")
+        Task(self.tw, description='test task')

         self.assertEqual(len(self.tw.tasks.all()), 0)
 
         self.assertEqual(len(self.tw.tasks.all()), 0)
 

-    # TODO: once python 2.6 compatiblity is over, use context managers here
+    # TODO: once python 2.6 compatibility is over, use context managers here

     #       and in all subsequent tests for assertRaises
 
     def test_delete_unsaved_task(self):
     #       and in all subsequent tests for assertRaises
 
     def test_delete_unsaved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertRaises(Task.NotSaved, t.delete)
 
     def test_complete_unsaved_task(self):
         self.assertRaises(Task.NotSaved, t.delete)
 
     def test_complete_unsaved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertRaises(Task.NotSaved, t.done)
 
     def test_refresh_unsaved_task(self):
         self.assertRaises(Task.NotSaved, t.done)
 
     def test_refresh_unsaved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertRaises(Task.NotSaved, t.refresh)
 
     def test_start_unsaved_task(self):
         self.assertRaises(Task.NotSaved, t.refresh)
 
     def test_start_unsaved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertRaises(Task.NotSaved, t.start)
 
     def test_delete_deleted_task(self):
         self.assertRaises(Task.NotSaved, t.start)
 
     def test_delete_deleted_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.delete()
 
         self.assertRaises(Task.DeletedTask, t.delete)
 
     def test_complete_completed_task(self):
         t.save()
         t.delete()
 
         self.assertRaises(Task.DeletedTask, t.delete)
 
     def test_complete_completed_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.done()
 
         self.assertRaises(Task.CompletedTask, t.done)
 
     def test_start_completed_task(self):
         t.save()
         t.done()
 
         self.assertRaises(Task.CompletedTask, t.done)
 
     def test_start_completed_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.done()
 
         self.assertRaises(Task.CompletedTask, t.start)
 
     def test_add_completed_task(self):
         t.save()
         t.done()
 
         self.assertRaises(Task.CompletedTask, t.start)
 
     def test_add_completed_task(self):

-        t = Task(self.tw, description="test", status="completed",
-                 end=datetime.datetime.now())
+        t = Task(
+            self.tw,
+            description='test',
+            status='completed',
+            end=datetime.datetime.now(),
+        )

         t.save()
 
     def test_add_multiple_completed_tasks(self):
         t.save()
 
     def test_add_multiple_completed_tasks(self):

-        t1 = Task(self.tw, description="test1", status="completed",
-                 end=datetime.datetime.now())
-        t2 = Task(self.tw, description="test2", status="completed",
-                 end=datetime.datetime.now())
+        t1 = Task(
+            self.tw,
+            description='test1',
+            status='completed',
+            end=datetime.datetime.now(),
+        )
+        t2 = Task(
+            self.tw,
+            description='test2',
+            status='completed',
+            end=datetime.datetime.now(),
+        )

         t1.save()
         t2.save()
 
     def test_complete_deleted_task(self):
         t1.save()
         t2.save()
 
     def test_complete_deleted_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.delete()
 
         self.assertRaises(Task.DeletedTask, t.done)
 
     def test_starting_task(self):
         t.save()
         t.delete()
 
         self.assertRaises(Task.DeletedTask, t.done)
 
     def test_starting_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.start()
         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.start()


@@ -317,7 +390,7 @@ class TaskTest(TasklibTest):
         self.assertEqual(t['status'], 'pending')
 
     def test_completing_task(self):
         self.assertEqual(t['status'], 'pending')
 
     def test_completing_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.done()
         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.done()


@@ -326,7 +399,7 @@ class TaskTest(TasklibTest):
         self.assertEqual(t['status'], 'completed')
 
     def test_deleting_task(self):
         self.assertEqual(t['status'], 'completed')
 
     def test_deleting_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.delete()
         now = t.datetime_normalizer(datetime.datetime.now())
         t.save()
         t.delete()


@@ -335,51 +408,51 @@ class TaskTest(TasklibTest):
         self.assertEqual(t['status'], 'deleted')
 
     def test_started_task_active(self):
         self.assertEqual(t['status'], 'deleted')
 
     def test_started_task_active(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.start()
         self.assertTrue(t.active)
 
     def test_unstarted_task_inactive(self):
         t.save()
         t.start()
         self.assertTrue(t.active)
 
     def test_unstarted_task_inactive(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertFalse(t.active)
         t.save()
         self.assertFalse(t.active)
 
     def test_start_active_task(self):
         self.assertFalse(t.active)
         t.save()
         self.assertFalse(t.active)
 
     def test_start_active_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.start()
         self.assertRaises(Task.ActiveTask, t.start)
 
     def test_stop_completed_task(self):
         t.save()
         t.start()
         self.assertRaises(Task.ActiveTask, t.start)
 
     def test_stop_completed_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.start()
         t.done()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 
         t.save()
         t.start()
         t.done()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.done()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 
     def test_stop_deleted_task(self):
         t.save()
         t.done()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 
     def test_stop_deleted_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.start()
         t.delete()
         t.stop()
 
     def test_stop_inactive_task(self):
         t.save()
         t.start()
         t.delete()
         t.stop()
 
     def test_stop_inactive_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 
         t.save()
 
         self.assertRaises(Task.InactiveTask, t.stop)
 

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.start()
         t.stop()
         t.save()
         t.start()
         t.stop()


@@ -387,8 +460,8 @@ class TaskTest(TasklibTest):
         self.assertRaises(Task.InactiveTask, t.stop)
 
     def test_stopping_task(self):
         self.assertRaises(Task.InactiveTask, t.stop)
 
     def test_stopping_task(self):

-        t = Task(self.tw, description="test task")
-        now = t.datetime_normalizer(datetime.datetime.now())
+        t = Task(self.tw, description='test task')
+        t.datetime_normalizer(datetime.datetime.now())

         t.save()
         t.start()
         t.stop()
         t.save()
         t.start()
         t.stop()


@@ -398,41 +471,41 @@ class TaskTest(TasklibTest):
         self.assertFalse(t.active)
 
     def test_modify_simple_attribute_without_space(self):
         self.assertFalse(t.active)
 
     def test_modify_simple_attribute_without_space(self):

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         t.save()
 

-        self.assertEquals(t['description'], "test")
+        self.assertEqual(t['description'], 'test')

 
 

-        t['description'] = "test-modified"
+        t['description'] = 'test-modified'

         t.save()
 
         t.save()
 

-        self.assertEquals(t['description'], "test-modified")
+        self.assertEqual(t['description'], 'test-modified')

 
     def test_modify_simple_attribute_with_space(self):
         # Space can pose problems with parsing
 
     def test_modify_simple_attribute_with_space(self):
         # Space can pose problems with parsing

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
 
         t.save()
 

-        self.assertEquals(t['description'], "test task")
+        self.assertEqual(t['description'], 'test task')

 
 

-        t['description'] = "test task modified"
+        t['description'] = 'test task modified'

         t.save()
 
         t.save()
 

-        self.assertEquals(t['description'], "test task modified")
+        self.assertEqual(t['description'], 'test task modified')

 
     def test_empty_dependency_set_of_unsaved_task(self):
 
     def test_empty_dependency_set_of_unsaved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         self.assertEqual(t['depends'], set())
 
     def test_empty_dependency_set_of_saved_task(self):
         self.assertEqual(t['depends'], set())
 
     def test_empty_dependency_set_of_saved_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         self.assertEqual(t['depends'], set())
 
     def test_set_unsaved_task_as_dependency(self):
         # Adds only one dependency to task with no dependencies
         t.save()
         self.assertEqual(t['depends'], set())
 
     def test_set_unsaved_task_as_dependency(self):
         # Adds only one dependency to task with no dependencies

-        t = Task(self.tw, description="test task")
-        dependency = Task(self.tw, description="needs to be done first")
+        t = Task(self.tw, description='test task')
+        dependency = Task(self.tw, description='needs to be done first')

 
         # We only save the parent task, dependency task is unsaved
         t.save()
 
         # We only save the parent task, dependency task is unsaved
         t.save()


@@ -442,8 +515,8 @@ class TaskTest(TasklibTest):
 
     def test_set_simple_dependency_set(self):
         # Adds only one dependency to task with no dependencies
 
     def test_set_simple_dependency_set(self):
         # Adds only one dependency to task with no dependencies

-        t = Task(self.tw, description="test task")
-        dependency = Task(self.tw, description="needs to be done first")
+        t = Task(self.tw, description='test task')
+        dependency = Task(self.tw, description='needs to be done first')

 
         t.save()
         dependency.save()
 
         t.save()
         dependency.save()


@@ -454,9 +527,9 @@ class TaskTest(TasklibTest):
 
     def test_set_complex_dependency_set(self):
         # Adds two dependencies to task with no dependencies
 
     def test_set_complex_dependency_set(self):
         # Adds two dependencies to task with no dependencies

-        t = Task(self.tw, description="test task")
-        dependency1 = Task(self.tw, description="needs to be done first")
-        dependency2 = Task(self.tw, description="needs to be done second")
+        t = Task(self.tw, description='test task')
+        dependency1 = Task(self.tw, description='needs to be done first')
+        dependency2 = Task(self.tw, description='needs to be done second')

 
         t.save()
         dependency1.save()
 
         t.save()
         dependency1.save()


@@ -468,9 +541,9 @@ class TaskTest(TasklibTest):
 
     def test_remove_from_dependency_set(self):
         # Removes dependency from task with two dependencies
 
     def test_remove_from_dependency_set(self):
         # Removes dependency from task with two dependencies

-        t = Task(self.tw, description="test task")
-        dependency1 = Task(self.tw, description="needs to be done first")
-        dependency2 = Task(self.tw, description="needs to be done second")
+        t = Task(self.tw, description='test task')
+        dependency1 = Task(self.tw, description='needs to be done first')
+        dependency2 = Task(self.tw, description='needs to be done second')

 
         dependency1.save()
         dependency2.save()
 
         dependency1.save()
         dependency2.save()


@@ -485,9 +558,9 @@ class TaskTest(TasklibTest):
 
     def test_add_to_dependency_set(self):
         # Adds dependency to task with one dependencies
 
     def test_add_to_dependency_set(self):
         # Adds dependency to task with one dependencies

-        t = Task(self.tw, description="test task")
-        dependency1 = Task(self.tw, description="needs to be done first")
-        dependency2 = Task(self.tw, description="needs to be done second")
+        t = Task(self.tw, description='test task')
+        dependency1 = Task(self.tw, description='needs to be done first')
+        dependency2 = Task(self.tw, description='needs to be done second')

 
         dependency1.save()
         dependency2.save()
 
         dependency1.save()
         dependency2.save()


@@ -502,8 +575,8 @@ class TaskTest(TasklibTest):
 
     def test_add_to_empty_dependency_set(self):
         # Adds dependency to task with one dependencies
 
     def test_add_to_empty_dependency_set(self):
         # Adds dependency to task with one dependencies

-        t = Task(self.tw, description="test task")
-        dependency = Task(self.tw, description="needs to be done first")
+        t = Task(self.tw, description='test task')
+        dependency = Task(self.tw, description='needs to be done first')

 
         dependency.save()
 
 
         dependency.save()
 


@@ -514,30 +587,30 @@ class TaskTest(TasklibTest):
 
     def test_simple_dependency_set_save_repeatedly(self):
         # Adds only one dependency to task with no dependencies
 
     def test_simple_dependency_set_save_repeatedly(self):
         # Adds only one dependency to task with no dependencies

-        t = Task(self.tw, description="test task")
-        dependency = Task(self.tw, description="needs to be done first")
+        t = Task(self.tw, description='test task')
+        dependency = Task(self.tw, description='needs to be done first')

         dependency.save()
 
         t['depends'] = set([dependency])
         t.save()
 
         # We taint the task, but keep depends intact
         dependency.save()
 
         t['depends'] = set([dependency])
         t.save()
 
         # We taint the task, but keep depends intact

-        t['description'] = "test task modified"
+        t['description'] = 'test task modified'

         t.save()
 
         self.assertEqual(t['depends'], set([dependency]))
 
         # We taint the task, but assign the same set to the depends
         t['depends'] = set([dependency])
         t.save()
 
         self.assertEqual(t['depends'], set([dependency]))
 
         # We taint the task, but assign the same set to the depends
         t['depends'] = set([dependency])

-        t['description'] = "test task modified again"
+        t['description'] = 'test task modified again'

         t.save()
 
         self.assertEqual(t['depends'], set([dependency]))
 
     def test_compare_different_tasks(self):
         # Negative: compare two different tasks
         t.save()
 
         self.assertEqual(t['depends'], set([dependency]))
 
     def test_compare_different_tasks(self):
         # Negative: compare two different tasks

-        t1 = Task(self.tw, description="test task")
-        t2 = Task(self.tw, description="test task")
+        t1 = Task(self.tw, description='test task')
+        t2 = Task(self.tw, description='test task')

 
         t1.save()
         t2.save()
 
         t1.save()
         t2.save()


@@ -546,14 +619,14 @@ class TaskTest(TasklibTest):
 
     def test_compare_same_task_object(self):
         # Compare Task object wit itself
 
     def test_compare_same_task_object(self):
         # Compare Task object wit itself

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
 
         self.assertEqual(t == t, True)
 
     def test_compare_same_task(self):
         # Compare the same task using two different objects
         t.save()
 
         self.assertEqual(t == t, True)
 
     def test_compare_same_task(self):
         # Compare the same task using two different objects

-        t1 = Task(self.tw, description="test task")
+        t1 = Task(self.tw, description='test task')

         t1.save()
 
         t2 = self.tw.tasks.get(uuid=t1['uuid'])
         t1.save()
 
         t2 = self.tw.tasks.get(uuid=t1['uuid'])


@@ -562,31 +635,48 @@ class TaskTest(TasklibTest):
     def test_compare_unsaved_tasks(self):
         # t1 and t2 are unsaved tasks, considered to be unequal
         # despite the content of data
     def test_compare_unsaved_tasks(self):
         # t1 and t2 are unsaved tasks, considered to be unequal
         # despite the content of data

-        t1 = Task(self.tw, description="test task")
-        t2 = Task(self.tw, description="test task")
+        t1 = Task(self.tw, description='test task')
+        t2 = Task(self.tw, description='test task')

 
         self.assertEqual(t1 == t2, False)
 
     def test_hash_unsaved_tasks(self):
         # Considered equal, it's the same object
 
         self.assertEqual(t1 == t2, False)
 
     def test_hash_unsaved_tasks(self):
         # Considered equal, it's the same object

-        t1 = Task(self.tw, description="test task")
+        t1 = Task(self.tw, description='test task')

         t2 = t1
         self.assertEqual(hash(t1) == hash(t2), True)
 
     def test_hash_same_task(self):
         # Compare the hash of the task using two different objects
         t2 = t1
         self.assertEqual(hash(t1) == hash(t2), True)
 
     def test_hash_same_task(self):
         # Compare the hash of the task using two different objects

-        t1 = Task(self.tw, description="test task")
+        t1 = Task(self.tw, description='test task')

         t1.save()
 
         t2 = self.tw.tasks.get(uuid=t1['uuid'])
         self.assertEqual(t1.__hash__(), t2.__hash__())
 
         t1.save()
 
         t2 = self.tw.tasks.get(uuid=t1['uuid'])
         self.assertEqual(t1.__hash__(), t2.__hash__())
 

+    def test_hash_unequal_unsaved_tasks(self):
+        # Compare the hash of the task using two different objects
+        t1 = Task(self.tw, description='test task 1')
+        t2 = Task(self.tw, description='test task 2')
+
+        self.assertNotEqual(t1.__hash__(), t2.__hash__())
+
+    def test_hash_unequal_saved_tasks(self):
+        # Compare the hash of the task using two different objects
+        t1 = Task(self.tw, description='test task 1')
+        t2 = Task(self.tw, description='test task 2')
+
+        t1.save()
+        t2.save()
+
+        self.assertNotEqual(t1.__hash__(), t2.__hash__())
+

     def test_adding_task_with_priority(self):
     def test_adding_task_with_priority(self):

-        t = Task(self.tw, description="test task", priority="M")
+        t = Task(self.tw, description='test task', priority='M')

         t.save()
 
     def test_removing_priority_with_none(self):
         t.save()
 
     def test_removing_priority_with_none(self):

-        t = Task(self.tw, description="test task", priority="L")
+        t = Task(self.tw, description='test task', priority='L')

         t.save()
 
         # Remove the priority mark
         t.save()
 
         # Remove the priority mark


@@ -597,11 +687,11 @@ class TaskTest(TasklibTest):
         self.assertEqual(t['priority'], None)
 
     def test_adding_task_with_due_time(self):
         self.assertEqual(t['priority'], None)
 
     def test_adding_task_with_due_time(self):

-        t = Task(self.tw, description="test task", due=datetime.datetime.now())
+        t = Task(self.tw, description='test task', due=datetime.datetime.now())

         t.save()
 
     def test_removing_due_time_with_none(self):
         t.save()
 
     def test_removing_due_time_with_none(self):

-        t = Task(self.tw, description="test task", due=datetime.datetime.now())
+        t = Task(self.tw, description='test task', due=datetime.datetime.now())

         t.save()
 
         # Remove the due timestamp
         t.save()
 
         # Remove the due timestamp


@@ -618,15 +708,17 @@ class TaskTest(TasklibTest):
         self.assertEqual(set(t._modified_fields), set())
 
         # Modify the task
         self.assertEqual(set(t._modified_fields), set())
 
         # Modify the task

-        t['description'] = "test task"
+        t['description'] = 'test task'

         self.assertEqual(set(t._modified_fields), set(['description']))
 
         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3
         self.assertEqual(set(t._modified_fields), set(['description', 'due']))
 
         self.assertEqual(set(t._modified_fields), set(['description']))
 
         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3
         self.assertEqual(set(t._modified_fields), set(['description', 'due']))
 

-        t['project'] = "test project"
-        self.assertEqual(set(t._modified_fields),
-                         set(['description', 'due', 'project']))
+        t['project'] = 'test project'
+        self.assertEqual(
+            set(t._modified_fields),
+            set(['description', 'due', 'project']),
+        )

 
         # List of modified fields should clear out when saved
         t.save()
 
         # List of modified fields should clear out when saved
         t.save()


@@ -634,20 +726,20 @@ class TaskTest(TasklibTest):
 
         # Reassigning the fields with the same values now should not produce
         # modified fields
 
         # Reassigning the fields with the same values now should not produce
         # modified fields

-        t['description'] = "test task"
+        t['description'] = 'test task'

         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3
         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3

-        t['project'] = "test project"
+        t['project'] = 'test project'

         self.assertEqual(set(t._modified_fields), set())
 
     def test_modified_fields_loaded_task(self):
         t = Task(self.tw)
 
         # Modify the task
         self.assertEqual(set(t._modified_fields), set())
 
     def test_modified_fields_loaded_task(self):
         t = Task(self.tw)
 
         # Modify the task

-        t['description'] = "test task"
+        t['description'] = 'test task'

         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3
         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3

-        t['project'] = "test project"
+        t['project'] = 'test project'

 
 

-        dependency = Task(self.tw, description="dependency")
+        dependency = Task(self.tw, description='dependency')

         dependency.save()
         t['depends'] = set([dependency])
 
         dependency.save()
         t['depends'] = set([dependency])
 


@@ -656,13 +748,13 @@ class TaskTest(TasklibTest):
         self.assertEqual(set(t._modified_fields), set())
 
         # Get the task by using a filter by UUID
         self.assertEqual(set(t._modified_fields), set())
 
         # Get the task by using a filter by UUID

-        t2 = self.tw.tasks.get(uuid=t['uuid'])
+        self.tw.tasks.get(uuid=t['uuid'])

 
         # Reassigning the fields with the same values now should not produce
         # modified fields
 
         # Reassigning the fields with the same values now should not produce
         # modified fields

-        t['description'] = "test task"
+        t['description'] = 'test task'

         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3
         t['due'] = datetime.datetime(2014, 2, 14, 14, 14, 14)  # <3

-        t['project'] = "test project"
+        t['project'] = 'test project'

         t['depends'] = set([dependency])
         self.assertEqual(set(t._modified_fields), set())
 
         t['depends'] = set([dependency])
         self.assertEqual(set(t._modified_fields), set())
 


@@ -670,7 +762,7 @@ class TaskTest(TasklibTest):
         t = Task(self.tw)
 
         for field in TASK_STANDARD_ATTRS:
         t = Task(self.tw)
 
         for field in TASK_STANDARD_ATTRS:

-            value = t[field]
+            t[field]

 
         self.assertEqual(set(t._modified_fields), set())
 
 
         self.assertEqual(set(t._modified_fields), set())
 


@@ -678,48 +770,70 @@ class TaskTest(TasklibTest):
         # Test that we are unable to set readonly attrs through __init__
         for readonly_key in Task.read_only_fields:
             kwargs = {'description': 'test task', readonly_key: 'value'}
         # Test that we are unable to set readonly attrs through __init__
         for readonly_key in Task.read_only_fields:
             kwargs = {'description': 'test task', readonly_key: 'value'}

-            self.assertRaises(RuntimeError,
-                              lambda: Task(self.tw, **kwargs))
+            self.assertRaises(
+                RuntimeError,
+                lambda: Task(self.tw, **kwargs),
+            )

 
     def test_setting_read_only_attrs_through_setitem(self):
         # Test that we are unable to set readonly attrs through __init__
         for readonly_key in Task.read_only_fields:
             t = Task(self.tw, description='test task')
 
     def test_setting_read_only_attrs_through_setitem(self):
         # Test that we are unable to set readonly attrs through __init__
         for readonly_key in Task.read_only_fields:
             t = Task(self.tw, description='test task')

-            self.assertRaises(RuntimeError,
-                              lambda: t.__setitem__(readonly_key, 'value'))
+            self.assertRaises(
+                RuntimeError,
+                lambda: t.__setitem__(readonly_key, 'value'),
+            )

 
     def test_saving_unmodified_task(self):
 
     def test_saving_unmodified_task(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.save()
 
     def test_adding_tag_by_appending(self):
         t.save()
         t.save()
 
     def test_adding_tag_by_appending(self):

-        t = Task(self.tw, description="test task", tags=['test1'])
+        t = Task(self.tw, description='test task', tags=['test1'])

         t.save()
         t.save()

-        t['tags'].append('test2')
+        t['tags'].add('test2')

         t.save()
         t.save()

-        self.assertEqual(t['tags'], ['test1', 'test2'])
+        self.assertEqual(t['tags'], set(['test1', 'test2']))
+
+    def test_adding_tag_twice(self):
+        t = Task(self.tw, description='test task', tags=['test1'])
+        t.save()
+        t['tags'].add('test2')
+        t['tags'].add('test2')
+        t.save()
+        self.assertEqual(t['tags'], set(['test1', 'test2']))

 
     def test_adding_tag_by_appending_empty(self):
 
     def test_adding_tag_by_appending_empty(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t.save()
         t.save()

-        t['tags'].append('test')
+        t['tags'].add('test')

         t.save()
         t.save()

-        self.assertEqual(t['tags'], ['test'])
+        self.assertEqual(t['tags'], set(['test']))

 
     def test_serializers_returning_empty_string_for_none(self):
         # Test that any serializer returns '' when passed None
         t = Task(self.tw)
 
     def test_serializers_returning_empty_string_for_none(self):
         # Test that any serializer returns '' when passed None
         t = Task(self.tw)

-        serializers = [getattr(t, serializer_name) for serializer_name in
-                       filter(lambda x: x.startswith('serialize_'), dir(t))]
+        serializers = [
+            getattr(t, serializer_name)
+            for serializer_name in filter(
+                lambda x: x.startswith('serialize_'),
+                dir(t),
+            )
+        ]

         for serializer in serializers:
             self.assertEqual(serializer(None), '')
 
     def test_deserializer_returning_empty_value_for_empty_string(self):
         # Test that any deserializer returns empty value when passed ''
         t = Task(self.tw)
         for serializer in serializers:
             self.assertEqual(serializer(None), '')
 
     def test_deserializer_returning_empty_value_for_empty_string(self):
         # Test that any deserializer returns empty value when passed ''
         t = Task(self.tw)

-        deserializers = [getattr(t, deserializer_name) for deserializer_name in
-                        filter(lambda x: x.startswith('deserialize_'), dir(t))]
+        deserializers = [
+            getattr(t, deserializer_name)
+            for deserializer_name in filter(
+                lambda x: x.startswith('deserialize_'),
+                dir(t),
+            )
+        ]

         for deserializer in deserializers:
             self.assertTrue(deserializer('') in (None, [], set()))
 
         for deserializer in deserializers:
             self.assertTrue(deserializer('') in (None, [], set()))
 


@@ -732,26 +846,46 @@ class TaskTest(TasklibTest):
 
     def test_recurrent_task_generation(self):
         today = datetime.date.today()
 
     def test_recurrent_task_generation(self):
         today = datetime.date.today()

-        t = Task(self.tw, description="brush teeth",
-                 due=today, recur="daily")
+        t = Task(
+            self.tw,
+            description='brush teeth',
+            due=today,
+            recur='daily',
+        )

         t.save()
         self.assertEqual(len(self.tw.tasks.pending()), 2)
 
         t.save()
         self.assertEqual(len(self.tw.tasks.pending()), 2)
 

+    def test_spawned_task_parent(self):
+        today = datetime.date.today()
+        t = Task(
+            self.tw,
+            description='brush teeth',
+            due=today,
+            recur='daily',
+        )
+        t.save()
+
+        spawned = self.tw.tasks.pending().get(due=today)
+        assert spawned['parent'] == t
+

     def test_modify_number_of_tasks_at_once(self):
         for i in range(1, 100):
     def test_modify_number_of_tasks_at_once(self):
         for i in range(1, 100):

-            Task(self.tw, description="test task %d" % i, tags=['test']).save()
+            Task(self.tw, description='test task %d' % i, tags=['test']).save()

 
         self.tw.execute_command(['+test', 'mod', 'unified', 'description'])
 
     def test_return_all_from_executed_command(self):
 
         self.tw.execute_command(['+test', 'mod', 'unified', 'description'])
 
     def test_return_all_from_executed_command(self):

-        Task(self.tw, description="test task", tags=['test']).save()
+        Task(self.tw, description='test task', tags=['test']).save()

         out, err, rc = self.tw.execute_command(['count'], return_all=True)
         self.assertEqual(rc, 0)
 
     def test_return_all_from_failed_executed_command(self):
         out, err, rc = self.tw.execute_command(['count'], return_all=True)
         self.assertEqual(rc, 0)
 
     def test_return_all_from_failed_executed_command(self):

-        Task(self.tw, description="test task", tags=['test']).save()
-        out, err, rc = self.tw.execute_command(['countinvalid'],
-            return_all=True, allow_failure=False)
+        Task(self.tw, description='test task', tags=['test']).save()
+        out, err, rc = self.tw.execute_command(
+            ['countinvalid'],
+            return_all=True,
+            allow_failure=False,
+        )

         self.assertNotEqual(rc, 0)
 
 
         self.assertNotEqual(rc, 0)
 
 


@@ -762,40 +896,74 @@ class TaskFromHookTest(TasklibTest):
         '"entry":"20141118T050231Z",'
         '"status":"pending",'
         '"start":"20141119T152233Z",'
         '"entry":"20141118T050231Z",'
         '"status":"pending",'
         '"start":"20141119T152233Z",'

-        '"uuid":"a360fc44-315c-4366-b70c-ea7e7520b749"}')
-
-    input_modify_data = six.StringIO(input_add_data.getvalue() + '\n' +
-        '{"description":"Buy some milk finally",'
-        '"entry":"20141118T050231Z",'
-        '"status":"completed",'
-        '"uuid":"a360fc44-315c-4366-b70c-ea7e7520b749"}')
+        '"uuid":"a360fc44-315c-4366-b70c-ea7e7520b749"}',
+    )
+
+    input_add_data_recurring = six.StringIO(
+        '{"description":"Mow the lawn",'
+        '"entry":"20160210T224304Z",'
+        '"parent":"62da6227-519c-42c2-915d-dccada926ad7",'
+        '"recur":"weekly",'
+        '"status":"pending",'
+        '"uuid":"81305335-0237-49ff-8e87-b3cdc2369cec"}',
+    )
+
+    input_modify_data = six.StringIO(
+        '\n'.join([
+            input_add_data.getvalue(),
+            (
+                '{"description":"Buy some milk finally",'
+                '"entry":"20141118T050231Z",'
+                '"status":"completed",'
+                '"uuid":"a360fc44-315c-4366-b70c-ea7e7520b749"}'
+            ),
+        ]),
+    )

 
     exported_raw_data = (
         '{"project":"Home",'
 
     exported_raw_data = (
         '{"project":"Home",'

-         '"due":"20150101T232323Z",'
-         '"description":"test task"}')
+        '"due":"20150101T232323Z",'
+        '"description":"test task"}'
+    )

 
     def test_setting_up_from_add_hook_input(self):
         t = Task.from_input(input_file=self.input_add_data, backend=self.tw)
 
     def test_setting_up_from_add_hook_input(self):
         t = Task.from_input(input_file=self.input_add_data, backend=self.tw)

-        self.assertEqual(t['description'], "Buy some milk")
+        self.assertEqual(t['description'], 'Buy some milk')
+        self.assertEqual(t.pending, True)
+
+    def test_setting_up_from_add_hook_input_recurring(self):
+        t = Task.from_input(
+            input_file=self.input_add_data_recurring,
+            backend=self.tw,
+        )
+        self.assertEqual(t['description'], 'Mow the lawn')

         self.assertEqual(t.pending, True)
 
     def test_setting_up_from_modified_hook_input(self):
         self.assertEqual(t.pending, True)
 
     def test_setting_up_from_modified_hook_input(self):

-        t = Task.from_input(input_file=self.input_modify_data, modify=True,
-                            backend=self.tw)
-        self.assertEqual(t['description'], "Buy some milk finally")
+        t = Task.from_input(
+            input_file=self.input_modify_data,
+            modify=True,
+            backend=self.tw,
+        )
+        self.assertEqual(t['description'], 'Buy some milk finally')

         self.assertEqual(t.pending, False)
         self.assertEqual(t.completed, True)
 
         self.assertEqual(t.pending, False)
         self.assertEqual(t.completed, True)
 

-        self.assertEqual(t._original_data['status'], "pending")
-        self.assertEqual(t._original_data['description'], "Buy some milk")
-        self.assertEqual(set(t._modified_fields),
-                         set(['status', 'description', 'start']))
+        self.assertEqual(t._original_data['status'], 'pending')
+        self.assertEqual(t._original_data['description'], 'Buy some milk')
+        self.assertEqual(
+            set(t._modified_fields),
+            set(['status', 'description', 'start']),
+        )

 
     def test_export_data(self):
 
     def test_export_data(self):

-        t = Task(self.tw, description="test task",
-            project="Home",
-            due=pytz.utc.localize(datetime.datetime(2015,1,1,23,23,23)))
+        t = Task(
+            self.tw,
+            description='test task',
+            project='Home',
+            due=pytz.utc.localize(
+                datetime.datetime(2015, 1, 1, 23, 23, 23)),
+        )

 
         # Check that the output is a permutation of:
         # {"project":"Home","description":"test task","due":"20150101232323Z"}
 
         # Check that the output is a permutation of:
         # {"project":"Home","description":"test task","due":"20150101232323Z"}


@@ -805,78 +973,88 @@ class TaskFromHookTest(TasklibTest):
             for segments in itertools.permutations(allowed_segments)
         ]
 
             for segments in itertools.permutations(allowed_segments)
         ]
 

-        self.assertTrue(any(t.export_data() == expected
-                            for expected in allowed_output))
+        self.assertTrue(
+            any(t.export_data() == expected
+                for expected in allowed_output),
+        )
+

 
 class TimezoneAwareDatetimeTest(TasklibTest):
 
     def setUp(self):
         super(TimezoneAwareDatetimeTest, self).setUp()
         self.zone = local_zone
 
 class TimezoneAwareDatetimeTest(TasklibTest):
 
     def setUp(self):
         super(TimezoneAwareDatetimeTest, self).setUp()
         self.zone = local_zone

-        self.localdate_naive = datetime.datetime(2015,2,2)
-        self.localtime_naive = datetime.datetime(2015,2,2,0,0,0)
+        self.localdate_naive = datetime.datetime(2015, 2, 2)
+        self.localtime_naive = datetime.datetime(2015, 2, 2, 0, 0, 0)

         self.localtime_aware = self.zone.localize(self.localtime_naive)
         self.utctime_aware = self.localtime_aware.astimezone(pytz.utc)
 
     def test_timezone_naive_datetime_setitem(self):
         self.localtime_aware = self.zone.localize(self.localtime_naive)
         self.utctime_aware = self.localtime_aware.astimezone(pytz.utc)
 
     def test_timezone_naive_datetime_setitem(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t['due'] = self.localtime_naive
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_naive_datetime_using_init(self):
         t['due'] = self.localtime_naive
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_naive_datetime_using_init(self):

-        t = Task(self.tw, description="test task", due=self.localtime_naive)
+        t = Task(self.tw, description='test task', due=self.localtime_naive)

         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_naive_datetime(self):
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_naive_datetime(self):

-        t = Task(self.tw, description="task1", due=self.localtime_naive)
+        t = Task(self.tw, description='task1', due=self.localtime_naive)

         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localtime_naive)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_naive_datetime(self):
         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localtime_naive)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_naive_datetime(self):

-        t = Task(self.tw, description="task1", due=self.localtime_naive)
-        self.assertEqual(json.loads(t.export_data())['due'],
-                         self.utctime_aware.strftime(DATE_FORMAT))
+        t = Task(self.tw, description='task1', due=self.localtime_naive)
+        self.assertEqual(
+            json.loads(t.export_data())['due'],
+            self.utctime_aware.strftime(DATE_FORMAT),
+        )

 
     def test_timezone_naive_date_setitem(self):
 
     def test_timezone_naive_date_setitem(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t['due'] = self.localdate_naive
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_naive_date_using_init(self):
         t['due'] = self.localdate_naive
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_naive_date_using_init(self):

-        t = Task(self.tw, description="test task", due=self.localdate_naive)
+        t = Task(self.tw, description='test task', due=self.localdate_naive)

         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_naive_date(self):
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_naive_date(self):

-        t = Task(self.tw, description="task1", due=self.localdate_naive)
+        t = Task(self.tw, description='task1', due=self.localdate_naive)

         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localdate_naive)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_naive_date(self):
         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localdate_naive)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_naive_date(self):

-        t = Task(self.tw, description="task1", due=self.localdate_naive)
-        self.assertEqual(json.loads(t.export_data())['due'],
-                         self.utctime_aware.strftime(DATE_FORMAT))
+        t = Task(self.tw, description='task1', due=self.localdate_naive)
+        self.assertEqual(
+            json.loads(t.export_data())['due'],
+            self.utctime_aware.strftime(DATE_FORMAT),
+        )

 
     def test_timezone_aware_datetime_setitem(self):
 
     def test_timezone_aware_datetime_setitem(self):

-        t = Task(self.tw, description="test task")
+        t = Task(self.tw, description='test task')

         t['due'] = self.localtime_aware
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_aware_datetime_using_init(self):
         t['due'] = self.localtime_aware
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_timezone_aware_datetime_using_init(self):

-        t = Task(self.tw, description="test task", due=self.localtime_aware)
+        t = Task(self.tw, description='test task', due=self.localtime_aware)

         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_aware_datetime(self):
         self.assertEqual(t['due'], self.localtime_aware)
 
     def test_filter_by_aware_datetime(self):

-        t = Task(self.tw, description="task1", due=self.localtime_aware)
+        t = Task(self.tw, description='task1', due=self.localtime_aware)

         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localtime_aware)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_aware_datetime(self):
         t.save()
         matching_tasks = self.tw.tasks.filter(due=self.localtime_aware)
         self.assertEqual(len(matching_tasks), 1)
 
     def test_serialize_aware_datetime(self):

-        t = Task(self.tw, description="task1", due=self.localtime_aware)
-        self.assertEqual(json.loads(t.export_data())['due'],
-                         self.utctime_aware.strftime(DATE_FORMAT))
+        t = Task(self.tw, description='task1', due=self.localtime_aware)
+        self.assertEqual(
+            json.loads(t.export_data())['due'],
+            self.utctime_aware.strftime(DATE_FORMAT),
+        )
+

 
 class DatetimeStringTest(TasklibTest):
 
 
 class DatetimeStringTest(TasklibTest):
 


@@ -889,11 +1067,11 @@ class DatetimeStringTest(TasklibTest):
             else:
                 return
 
             else:
                 return
 

-        t = Task(self.tw, description="test task", due="now")
+        t = Task(self.tw, description='test task', due='now')

         now = local_zone.localize(datetime.datetime.now())
 
         # Assert that both times are not more than 5 seconds apart
         now = local_zone.localize(datetime.datetime.now())
 
         # Assert that both times are not more than 5 seconds apart

-        if sys.version_info < (2,7):
+        if sys.version_info < (2, 7):

             self.assertTrue(total_seconds_2_6(now - t['due']) < 5)
             self.assertTrue(total_seconds_2_6(t['due'] - now) < 5)
         else:
             self.assertTrue(total_seconds_2_6(now - t['due']) < 5)
             self.assertTrue(total_seconds_2_6(t['due'] - now) < 5)
         else:


@@ -909,7 +1087,7 @@ class DatetimeStringTest(TasklibTest):
             else:
                 return
 
             else:
                 return
 

-        t = Task(self.tw, description="test task", due="eoy")
+        t = Task(self.tw, description='test task', due='eoy')

         now = local_zone.localize(datetime.datetime.now())
         eoy = local_zone.localize(datetime.datetime(
             year=now.year,
         now = local_zone.localize(datetime.datetime.now())
         eoy = local_zone.localize(datetime.datetime(
             year=now.year,


@@ -917,7 +1095,7 @@ class DatetimeStringTest(TasklibTest):
             day=31,
             hour=23,
             minute=59,
             day=31,
             hour=23,
             minute=59,

-            second=59
+            second=59,

             ))
         self.assertEqual(eoy, t['due'])
 
             ))
         self.assertEqual(eoy, t['due'])
 


@@ -930,16 +1108,18 @@ class DatetimeStringTest(TasklibTest):
             else:
                 return
 
             else:
                 return
 

-        t = Task(self.tw, description="test task", due="eoy - 4 months")
+        t = Task(self.tw, description='test task', due='eoy - 4 months')

         now = local_zone.localize(datetime.datetime.now())
         now = local_zone.localize(datetime.datetime.now())

-        due_date = local_zone.localize(datetime.datetime(
-            year=now.year,
-            month=12,
-            day=31,
-            hour=23,
-            minute=59,
-            second=59
-            )) - datetime.timedelta(0,4 * 30 * 86400)
+        due_date = local_zone.localize(
+            datetime.datetime(
+                year=now.year,
+                month=12,
+                day=31,
+                hour=23,
+                minute=59,
+                second=59,
+            )
+        ) - datetime.timedelta(0, 4 * 30 * 86400)

         self.assertEqual(due_date, t['due'])
 
     def test_filtering_with_string_datetime(self):
         self.assertEqual(due_date, t['due'])
 
     def test_filtering_with_string_datetime(self):


@@ -951,16 +1131,20 @@ class DatetimeStringTest(TasklibTest):
             else:
                 return
 
             else:
                 return
 

-        t = Task(self.tw, description="test task",
-                 due=datetime.datetime.now() - datetime.timedelta(0,2))
+        t = Task(
+            self.tw,
+            description='test task',
+            due=datetime.datetime.now() - datetime.timedelta(0, 2),
+        )

         t.save()
         t.save()

-        self.assertEqual(len(self.tw.tasks.filter(due__before="now")), 1)
+        self.assertEqual(len(self.tw.tasks.filter(due__before='now')), 1)
+

 
 class AnnotationTest(TasklibTest):
 
     def setUp(self):
         super(AnnotationTest, self).setUp()
 
 class AnnotationTest(TasklibTest):
 
     def setUp(self):
         super(AnnotationTest, self).setUp()

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

 
     def test_adding_annotation(self):
         task = self.tw.tasks.get()
 
     def test_adding_annotation(self):
         task = self.tw.tasks.get()


@@ -990,20 +1174,20 @@ class AnnotationTest(TasklibTest):
         self.assertEqual(len(task['annotations']), 0)
 
     def test_annotation_after_modification(self):
         self.assertEqual(len(task['annotations']), 0)
 
     def test_annotation_after_modification(self):

-         task = self.tw.tasks.get()
-         task['project'] = 'test'
-         task.add_annotation('I should really do this task')
-         self.assertEqual(task['project'], 'test')
-         task.save()
-         self.assertEqual(task['project'], 'test')
+        task = self.tw.tasks.get()
+        task['project'] = 'test'
+        task.add_annotation('I should really do this task')
+        self.assertEqual(task['project'], 'test')
+        task.save()
+        self.assertEqual(task['project'], 'test')

 
     def test_serialize_annotations(self):
         # Test that serializing annotations is possible
 
     def test_serialize_annotations(self):
         # Test that serializing annotations is possible

-        t = Task(self.tw, description="test")
+        t = Task(self.tw, description='test')

         t.save()
 
         t.save()
 

-        t.add_annotation("annotation1")
-        t.add_annotation("annotation2")
+        t.add_annotation('annotation1')
+        t.add_annotation('annotation2')

 
         data = t._serialize('annotations', t._data['annotations'])
 
 
         data = t._serialize('annotations', t._data['annotations'])
 


@@ -1011,59 +1195,66 @@ class AnnotationTest(TasklibTest):
         self.assertEqual(type(data[0]), dict)
         self.assertEqual(type(data[1]), dict)
 
         self.assertEqual(type(data[0]), dict)
         self.assertEqual(type(data[1]), dict)
 

-        self.assertEqual(data[0]['description'], "annotation1")
-        self.assertEqual(data[1]['description'], "annotation2")
+        self.assertEqual(data[0]['description'], 'annotation1')
+        self.assertEqual(data[1]['description'], 'annotation2')

 
 
 class UnicodeTest(TasklibTest):
 
     def test_unicode_task(self):
 
 
 class UnicodeTest(TasklibTest):
 
     def test_unicode_task(self):

-        Task(self.tw, description=six.u("†åßk")).save()
+        Task(self.tw, description=six.u('†åßk')).save()

         self.tw.tasks.get()
 
     def test_filter_by_unicode_task(self):
         self.tw.tasks.get()
 
     def test_filter_by_unicode_task(self):

-        Task(self.tw, description=six.u("†åßk")).save()
-        tasks = self.tw.tasks.filter(description=six.u("†åßk"))
+        Task(self.tw, description=six.u('†åßk')).save()
+        tasks = self.tw.tasks.filter(description=six.u('†åßk'))

         self.assertEqual(len(tasks), 1)
 
     def test_non_unicode_task(self):
         self.assertEqual(len(tasks), 1)
 
     def test_non_unicode_task(self):

-        Task(self.tw, description="test task").save()
+        Task(self.tw, description='test task').save()

         self.tw.tasks.get()
 
         self.tw.tasks.get()
 

+

 class ReadOnlyDictViewTest(unittest.TestCase):
 
     def setUp(self):
 class ReadOnlyDictViewTest(unittest.TestCase):
 
     def setUp(self):

-        self.sample = dict(l=[1,2,3], d={'k':'v'})
+        self.sample = dict(sample_list=[1, 2, 3], sample_dict={'key': 'value'})

         self.original_sample = copy.deepcopy(self.sample)
         self.view = ReadOnlyDictView(self.sample)
 
     def test_readonlydictview_getitem(self):
         self.original_sample = copy.deepcopy(self.sample)
         self.view = ReadOnlyDictView(self.sample)
 
     def test_readonlydictview_getitem(self):

-        l = self.view['l']
-        self.assertEqual(l, self.sample['l'])
+        sample_list = self.view['sample_list']
+        self.assertEqual(sample_list, self.sample['sample_list'])

 
         # Assert that modification changed only copied value
 
         # Assert that modification changed only copied value

-        l.append(4)
-        self.assertNotEqual(l, self.sample['l'])
+        sample_list.append(4)
+        self.assertNotEqual(sample_list, self.sample['sample_list'])

 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)
 
     def test_readonlydictview_contains(self):
 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)
 
     def test_readonlydictview_contains(self):

-        self.assertEqual('l' in self.view, 'l' in self.sample)
-        self.assertEqual('d' in self.view, 'd' in self.sample)
-        self.assertEqual('k' in self.view, 'k' in self.sample)
+        self.assertEqual('sample_list' in self.view,
+                         'sample_list' in self.sample)
+        self.assertEqual('sample_dict' in self.view,
+                         'sample_dict' in self.sample)
+        self.assertEqual('key' in self.view, 'key' in self.sample)

 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)
 
     def test_readonlydictview_iter(self):
 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)
 
     def test_readonlydictview_iter(self):

-        self.assertEqual(list(k for k in self.view),
-                         list(k for k in self.sample))
+        self.assertEqual(
+            list(key for key in self.view),
+            list(key for key in self.sample),
+        )

 
         # Assert the view is correct after modification
         self.sample['new'] = 'value'
 
         # Assert the view is correct after modification
         self.sample['new'] = 'value'

-        self.assertEqual(list(k for k in self.view),
-                         list(k for k in self.sample))
+        self.assertEqual(
+            list(key for key in self.view),
+            list(key for key in self.sample),
+        )

 
     def test_readonlydictview_len(self):
         self.assertEqual(len(self.view), len(self.sample))
 
     def test_readonlydictview_len(self):
         self.assertEqual(len(self.view), len(self.sample))


@@ -1073,12 +1264,12 @@ class ReadOnlyDictViewTest(unittest.TestCase):
         self.assertEqual(len(self.view), len(self.sample))
 
     def test_readonlydictview_get(self):
         self.assertEqual(len(self.view), len(self.sample))
 
     def test_readonlydictview_get(self):

-        l = self.view.get('l')
-        self.assertEqual(l, self.sample.get('l'))
+        sample_list = self.view.get('sample_list')
+        self.assertEqual(sample_list, self.sample.get('sample_list'))

 
         # Assert that modification changed only copied value
 
         # Assert that modification changed only copied value

-        l.append(4)
-        self.assertNotEqual(l, self.sample.get('l'))
+        sample_list.append(4)
+        self.assertNotEqual(sample_list, self.sample.get('sample_list'))

 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)
 
         # Assert that viewed dict is not changed
         self.assertEqual(self.sample, self.original_sample)


@@ -1109,7 +1300,7 @@ class LazyUUIDTaskTest(TasklibTest):
     def setUp(self):
         super(LazyUUIDTaskTest, self).setUp()
 
     def setUp(self):
         super(LazyUUIDTaskTest, self).setUp()
 

-        self.stored = Task(self.tw, description="this is test task")
+        self.stored = Task(self.tw, description='this is test task')

         self.stored.save()
 
         self.lazy = LazyUUIDTask(self.tw, self.stored['uuid'])
         self.stored.save()
 
         self.lazy = LazyUUIDTask(self.tw, self.stored['uuid'])


@@ -1134,6 +1325,7 @@ class LazyUUIDTaskTest(TasklibTest):
 
     def test_normal_to_lazy_equality(self):
         assert self.stored == self.lazy
 
     def test_normal_to_lazy_equality(self):
         assert self.stored == self.lazy

+        assert not self.stored != self.lazy

         assert type(self.lazy) is LazyUUIDTask
 
     def test_lazy_to_lazy_equality(self):
         assert type(self.lazy) is LazyUUIDTask
 
     def test_lazy_to_lazy_equality(self):


@@ -1141,6 +1333,31 @@ class LazyUUIDTaskTest(TasklibTest):
         lazy2 = LazyUUIDTask(self.tw, self.stored['uuid'])
 
         assert lazy1 == lazy2
         lazy2 = LazyUUIDTask(self.tw, self.stored['uuid'])
 
         assert lazy1 == lazy2

+        assert not lazy1 != lazy2
+        assert type(lazy1) is LazyUUIDTask
+        assert type(lazy2) is LazyUUIDTask
+
+    def test_normal_to_lazy_inequality(self):
+        # Create a different UUID by changing the last letter
+        wrong_uuid = self.stored['uuid']
+        wrong_uuid = wrong_uuid[:-1] + ('a' if wrong_uuid[-1] != 'a' else 'b')
+
+        wrong_lazy = LazyUUIDTask(self.tw, wrong_uuid)
+
+        assert not self.stored == wrong_lazy
+        assert self.stored != wrong_lazy
+        assert type(wrong_lazy) is LazyUUIDTask
+
+    def test_lazy_to_lazy_inequality(self):
+        # Create a different UUID by changing the last letter
+        wrong_uuid = self.stored['uuid']
+        wrong_uuid = wrong_uuid[:-1] + ('a' if wrong_uuid[-1] != 'a' else 'b')
+
+        lazy1 = LazyUUIDTask(self.tw, self.stored['uuid'])
+        lazy2 = LazyUUIDTask(self.tw, wrong_uuid)
+
+        assert not lazy1 == lazy2
+        assert lazy1 != lazy2

         assert type(lazy1) is LazyUUIDTask
         assert type(lazy2) is LazyUUIDTask
 
         assert type(lazy1) is LazyUUIDTask
         assert type(lazy2) is LazyUUIDTask
 


@@ -1165,9 +1382,9 @@ class LazyUUIDTaskSetTest(TasklibTest):
     def setUp(self):
         super(LazyUUIDTaskSetTest, self).setUp()
 
     def setUp(self):
         super(LazyUUIDTaskSetTest, self).setUp()
 

-        self.task1 = Task(self.tw, description="task 1")
-        self.task2 = Task(self.tw, description="task 2")
-        self.task3 = Task(self.tw, description="task 3")
+        self.task1 = Task(self.tw, description='task 1')
+        self.task2 = Task(self.tw, description='task 2')
+        self.task3 = Task(self.tw, description='task 3')

 
         self.task1.save()
         self.task2.save()
 
         self.task1.save()
         self.task2.save()


@@ -1176,7 +1393,7 @@ class LazyUUIDTaskSetTest(TasklibTest):
         self.uuids = (
             self.task1['uuid'],
             self.task2['uuid'],
         self.uuids = (
             self.task1['uuid'],
             self.task2['uuid'],

-            self.task3['uuid']
+            self.task3['uuid'],

         )
 
         self.lazy = LazyUUIDTaskSet(self.tw, self.uuids)
         )
 
         self.lazy = LazyUUIDTaskSet(self.tw, self.uuids)


@@ -1203,3 +1420,77 @@ class LazyUUIDTaskSetTest(TasklibTest):
         assert not self.lazy != self.tw.tasks.all()
 
         assert type(self.lazy) is LazyUUIDTaskSet
         assert not self.lazy != self.tw.tasks.all()
 
         assert type(self.lazy) is LazyUUIDTaskSet

+
+    def test_union(self):
+        taskset = set([self.task1])
+        lazyset = LazyUUIDTaskSet(
+            self.tw,
+            (self.task2['uuid'], self.task3['uuid']),
+        )
+
+        assert taskset | lazyset == self.lazy
+        assert lazyset | taskset == self.lazy
+        assert taskset.union(lazyset) == self.lazy
+        assert lazyset.union(taskset) == self.lazy
+
+        lazyset |= taskset
+        assert lazyset == self.lazy
+
+    def test_difference(self):
+        taskset = set([self.task1, self.task2])
+        lazyset = LazyUUIDTaskSet(
+            self.tw,
+            (self.task2['uuid'], self.task3['uuid']),
+        )
+
+        assert taskset - lazyset == set([self.task1])
+        assert lazyset - taskset == set([self.task3])
+        assert taskset.difference(lazyset) == set([self.task1])
+        assert lazyset.difference(taskset) == set([self.task3])
+
+        lazyset -= taskset
+        assert lazyset == set([self.task3])
+
+    def test_symmetric_difference(self):
+        taskset = set([self.task1, self.task2])
+        lazyset = LazyUUIDTaskSet(
+            self.tw,
+            (self.task2['uuid'], self.task3['uuid']),
+        )
+
+        assert taskset ^ lazyset == set([self.task1, self.task3])
+        assert lazyset ^ taskset == set([self.task1, self.task3])
+        self.assertEqual(
+            taskset.symmetric_difference(lazyset),
+            set([self.task1, self.task3]),
+        )
+        self.assertEqual(
+            lazyset.symmetric_difference(taskset),
+            set([self.task1, self.task3]),
+        )
+
+        lazyset ^= taskset
+        assert lazyset == set([self.task1, self.task3])
+
+    def test_intersection(self):
+        taskset = set([self.task1, self.task2])
+        lazyset = LazyUUIDTaskSet(
+            self.tw,
+            (self.task2['uuid'], self.task3['uuid']),
+        )
+
+        assert taskset & lazyset == set([self.task2])
+        assert lazyset & taskset == set([self.task2])
+        assert taskset.intersection(lazyset) == set([self.task2])
+        assert lazyset.intersection(taskset) == set([self.task2])
+
+        lazyset &= taskset
+        assert lazyset == set([self.task2])
+
+
+class TaskWarriorBackendTest(TasklibTest):
+
+    def test_config(self):
+        assert self.tw.config['nag'] == 'You have more urgent tasks.'
+        assert self.tw.config['default.command'] == 'next'
+        assert self.tw.config['dependency.indicator'] == 'D'