Add return value to move_up-down methods

tests/test_dlist.py

@@ -118,11 +118,11 @@ class TestMoveUp(unittest.TestCase):
         self.dlist = DownloadList(mocks)
 
     def test_move_up(self):
-        self.dlist.move_up(1)
+        self.assertTrue(self.dlist.move_up(1))
         self.assertEqual(self.dlist._items_list, [1, 0, 2])
 
     def test_move_up_already_on_top(self):
-        self.dlist.move_up(0)
+        self.assertFalse(self.dlist.move_up(0))
         self.assertEqual(self.dlist._items_list, [0, 1, 2])
 
     def test_move_up_not_exist(self):
@@ -138,11 +138,11 @@ class TestMoveDown(unittest.TestCase):
         self.dlist = DownloadList(mocks)
 
     def test_move_down(self):
-        self.dlist.move_down(1)
+        self.assertTrue(self.dlist.move_down(1))
         self.assertEqual(self.dlist._items_list, [0, 2, 1])
 
     def test_move_down_already_on_bottom(self):
-        self.dlist.move_down(2)
+        self.assertFalse(self.dlist.move_down(2))
         self.assertEqual(self.dlist._items_list, [0, 1, 2])
 
     def test_move_down_not_exist(self):

youtube_dl_gui/downloadmanager.py

@@ -235,6 +235,9 @@ class DownloadList(object):
 
         if index > 0:
             self._swap(index, index - 1)
+            return True
+
+        return False
 
     @synchronized(_SYNC_LOCK)
     def move_down(self, object_id):
@@ -243,6 +246,9 @@ class DownloadList(object):
 
         if index < (len(self._items_list) - 1):
             self._swap(index, index + 1)
+            return True
+
+        return False
 
     @synchronized(_SYNC_LOCK)
     def get_item(self, object_id):