Refactor BaseCurrentPlaylistController.get_by_{id,uri} into a generic get(**criteria)

mopidy/backends/__init__.py

@@ -90,33 +90,28 @@ class BaseCurrentPlaylistController(object):
         self.backend.playback.current_track = None
         self.playlist = Playlist()
 
-    def get_by_id(self, id):
+    def get(self, **criteria):
         """
-        Get track by ID. Raises :class:`KeyError` if not found.
+        Get track by given criterias. Raises :class:`KeyError` if not found.
 
-        :param id: track ID
-        :type id: int
+        Examples::
+
+            get(id=1)       # Returns track with ID 1
+            get(uri='xyz')  # Returns track with URI 'xyz'
+
+        :param **criteria: on or more criteria to match by
+        :type **criteria: dict
         :rtype: :class:`mopidy.models.Track`
         """
-        matches = filter(lambda t: t.id == id, self._playlist.tracks)
+        matches = self._playlist.tracks
+        for (key, value) in criteria.iteritems():
+            matches = filter(lambda t: getattr(t, key) == value, matches)
         if matches:
             return matches[0]
         else:
-            raise KeyError('Track with ID "%s" not found' % id)
-
-    def get_by_uri(self, uri):
-        """
-        Get track by URI. Raises :class:`KeyError` if not found.
-
-        :param uri: track URI
-        :type uri: string
-        :rtype: :class:`mopidy.models.Track`
-        """
-        matches = filter(lambda t: t.uri == uri, self._playlist.tracks)
-        if matches:
-            return matches[0]
-        else:
-            raise KeyError('Track with URI "%s" not found' % uri)
+            criteria_string = ', '.join(
+                ['%s=%s' % (k, v) for (k, v) in criteria.iteritems()])
+            raise KeyError(u'Track matching "%s" not found' % criteria_string)
 
     def load(self, playlist):
         """

tests/backends/get_test.py

@@ -11,17 +11,17 @@ class CurrentPlaylistGetTest(unittest.TestCase):
     def test_get_by_id_returns_unique_match(self):
         track = Track(id=1)
         self.c.playlist = Playlist(tracks=[Track(id=13), track, Track(id=17)])
-        self.assertEqual(track, self.c.get_by_id(1))
+        self.assertEqual(track, self.c.get(id=1))
 
     def test_get_by_id_returns_first_of_multiple_matches(self):
         track = Track(id=1)
         self.c.playlist = Playlist(tracks=[Track(id=13), track, track])
-        self.assertEqual(track, self.c.get_by_id(1))
+        self.assertEqual(track, self.c.get(id=1))
 
     def test_get_by_id_raises_keyerror_if_no_match(self):
         self.c.playlist = Playlist(tracks=[Track(id=13), Track(id=17)])
         try:
-            self.c.get_by_id(1)
+            self.c.get(id=1)
             self.fail(u'Should raise KeyError if no match')
         except KeyError:
             pass
@@ -30,17 +30,33 @@ class CurrentPlaylistGetTest(unittest.TestCase):
         track = Track(uri='a')
         self.c.playlist = Playlist(
             tracks=[Track(uri='z'), track, Track(uri='y')])
-        self.assertEqual(track, self.c.get_by_uri('a'))
+        self.assertEqual(track, self.c.get(uri='a'))
 
     def test_get_by_uri_returns_first_of_multiple_matches(self):
         track = Track(uri='a')
         self.c.playlist = Playlist(tracks=[Track(uri='z'), track, track])
-        self.assertEqual(track, self.c.get_by_uri('a'))
+        self.assertEqual(track, self.c.get(uri='a'))
 
     def test_get_by_uri_raises_keyerror_if_no_match(self):
         self.c.playlist = Playlist(tracks=[Track(uri='z'), Track(uri='y')])
         try:
-            self.c.get_by_uri('a')
+            self.c.get(uri='a')
             self.fail(u'Should raise KeyError if no match')
-        except KeyError:
-            pass
+        except KeyError as e:
+            self.assertEqual(u'Track matching "uri=a" not found', e[0])
+
+    def test_get_by_multiple_criteria_returns_elements_matching_all(self):
+        track1 = Track(id=1, uri='a')
+        track2 = Track(id=1, uri='b')
+        track3 = Track(id=2, uri='b')
+        self.c.playlist = Playlist(tracks=[track1, track2, track3])
+        self.assertEqual(track1, self.c.get(id=1, uri='a'))
+        self.assertEqual(track2, self.c.get(id=1, uri='b'))
+        self.assertEqual(track3, self.c.get(id=2, uri='b'))
+
+    def test_get_by_criteria_that_is_not_present_in_all_elements(self):
+        track1 = Track(id=1)
+        track2 = Track(uri='b')
+        track3 = Track(id=2)
+        self.c.playlist = Playlist(tracks=[track1, track2, track3])
+        self.assertEqual(track1, self.c.get(id=1))