Make core.stored_playlists.playlists read-only (#217)

docs/changes.rst

@@ -56,6 +56,13 @@ backends:
   dummy/mocked lower layers easier than with the old variant, where
   dependencies where looked up in Pykka's actor registry.
 
+- The stored playlists part of the core API have been revised a bit:
+
+  - :attr:`mopidy.core.StoredPlaylistsController.playlists` no longer supports
+    assignment to it. The `playlists` property on the backend layer still does,
+    and all functionality is maintained by assigning to the playlists
+    collections at the backend level.
+
 **Changes**
 
 - Made the :mod:`NAD mixer <mopidy.audio.mixers.nad>` responsive to interrupts

mopidy/core/stored_playlists.py

@@ -15,17 +15,12 @@ class StoredPlaylistsController(object):
         """
         Currently stored playlists.
 
-        Read/write. List of :class:`mopidy.models.Playlist`.
+        Read-only. List of :class:`mopidy.models.Playlist`.
         """
         futures = [b.stored_playlists.playlists for b in self.backends]
         results = pykka.get_all(futures)
         return list(itertools.chain(*results))
 
-    @playlists.setter  # noqa
-    def playlists(self, playlists):
-        # TODO Support multiple backends
-        self.backends[0].stored_playlists.playlists = playlists
-
     def create(self, name):
         """
         Create a new playlist.

tests/backends/base/stored_playlists.py

@@ -65,12 +65,13 @@ class StoredPlaylistsControllerTest(object):
 
     def test_get_by_name_returns_unique_match(self):
         playlist = Playlist(name='b')
-        self.stored.playlists = [Playlist(name='a'), playlist]
+        self.backend.stored_playlists.playlists = [
+            Playlist(name='a'), playlist]
         self.assertEqual(playlist, self.stored.get(name='b'))
 
     def test_get_by_name_returns_first_of_multiple_matches(self):
         playlist = Playlist(name='b')
-        self.stored.playlists = [
+        self.backend.stored_playlists.playlists = [
             playlist, Playlist(name='a'), Playlist(name='b')]
         try:
             self.stored.get(name='b')
@@ -79,7 +80,8 @@ class StoredPlaylistsControllerTest(object):
             self.assertEqual(u'"name=b" match multiple playlists', e[0])
 
     def test_get_by_name_raises_keyerror_if_no_match(self):
-        self.stored.playlists = [Playlist(name='a'), Playlist(name='b')]
+        self.backend.stored_playlists.playlists = [
+            Playlist(name='a'), Playlist(name='b')]
         try:
             self.stored.get(name='c')
             self.fail(u'Should raise LookupError if no match')

tests/frontends/mpd/protocol/stored_playlists_test.py

@@ -7,7 +7,7 @@ from tests.frontends.mpd import protocol
 
 class StoredPlaylistsHandlerTest(protocol.BaseTestCase):
     def test_listplaylist(self):
-        self.core.stored_playlists.playlists = [
+        self.backend.stored_playlists.playlists = [
             Playlist(name='name', tracks=[Track(uri='file:///dev/urandom')])]
 
         self.sendRequest(u'listplaylist "name"')
@@ -19,7 +19,7 @@ class StoredPlaylistsHandlerTest(protocol.BaseTestCase):
         self.assertEqualResponse(u'ACK [50@0] {listplaylist} No such playlist')
 
     def test_listplaylistinfo(self):
-        self.core.stored_playlists.playlists = [
+        self.backend.stored_playlists.playlists = [
             Playlist(name='name', tracks=[Track(uri='file:///dev/urandom')])]
 
         self.sendRequest(u'listplaylistinfo "name"')
@@ -35,7 +35,7 @@ class StoredPlaylistsHandlerTest(protocol.BaseTestCase):
 
     def test_listplaylists(self):
         last_modified = datetime.datetime(2001, 3, 17, 13, 41, 17, 12345)
-        self.core.stored_playlists.playlists = [
+        self.backend.stored_playlists.playlists = [
             Playlist(name='a', last_modified=last_modified)]
 
         self.sendRequest(u'listplaylists')
@@ -47,7 +47,7 @@ class StoredPlaylistsHandlerTest(protocol.BaseTestCase):
     def test_load_known_playlist_appends_to_current_playlist(self):
         self.core.current_playlist.append([Track(uri='a'), Track(uri='b')])
         self.assertEqual(len(self.core.current_playlist.tracks.get()), 2)
-        self.core.stored_playlists.playlists = [
+        self.backend.stored_playlists.playlists = [
             Playlist(name='A-list', tracks=[
                 Track(uri='c'), Track(uri='d'), Track(uri='e')])]