Add test shuffle and shuffle method

mopidy/backends/__init__.py

@@ -1,4 +1,5 @@
 import logging
+import random
 import time
 
 from mopidy.exceptions import MpdNotImplemented
@@ -44,11 +45,16 @@ class BaseCurrentPlaylistController(object):
 
     def remove(self, position):
         tracks = self.playlist.tracks
-
         del tracks[position]
 
         self.playlist = Playlist(tracks=tracks)
 
+    def shuffle(self, start=None, end=None):
+        tracks = self.playlist.tracks
+        random.shuffle(tracks)
+
+        self.playlist = Playlist(tracks=tracks)
+
 class BasePlaybackController(object):
     PAUSED = 'paused'
     PLAYING = 'playing'

tests/backends/__init__.py

@@ -1,3 +1,5 @@
+import random
+
 from mopidy.models import Track, Playlist
 
 def populate_playlist(func):
@@ -86,6 +88,17 @@ class BaseCurrentPlaylistControllerTest(object):
 
         self.assertNotEqual(track, self.controller.playlist.tracks[1])
 
+    @populate_playlist
+    def test_shuffle_all(self):
+        tracks = self.controller.playlist.tracks
+        random.seed(1)
+        self.controller.shuffle()
+
+        shuffled_tracks = self.controller.playlist.tracks
+
+        self.assertNotEqual(tracks, shuffled_tracks)
+        self.assertEqual(set(tracks), set(shuffled_tracks))
+
 class BasePlaybackControllerTest(object):
     uris = []
     backend_class = None