library: Fail nicely on lookups when offline

mopidy_spotify/library.py

@@ -30,17 +30,22 @@ def lookup(self, uri):
             logger.info('Failed to lookup "%s": %s', uri, exc)
             return []
 
-        if sp_link.type is spotify.LinkType.TRACK:
-            return list(self._lookup_track(sp_link))
-        elif sp_link.type is spotify.LinkType.ALBUM:
-            return list(self._lookup_album(sp_link))
-        elif sp_link.type is spotify.LinkType.ARTIST:
-            return list(self._lookup_artist(sp_link))
-        elif sp_link.type is spotify.LinkType.PLAYLIST:
-            return list(self._lookup_playlist(sp_link))
-        else:
-            logger.info(
-                'Failed to lookup "%s": Cannot handle %r', uri, sp_link.type)
+        try:
+            if sp_link.type is spotify.LinkType.TRACK:
+                return list(self._lookup_track(sp_link))
+            elif sp_link.type is spotify.LinkType.ALBUM:
+                return list(self._lookup_album(sp_link))
+            elif sp_link.type is spotify.LinkType.ARTIST:
+                return list(self._lookup_artist(sp_link))
+            elif sp_link.type is spotify.LinkType.PLAYLIST:
+                return list(self._lookup_playlist(sp_link))
+            else:
+                logger.info(
+                    'Failed to lookup "%s": Cannot handle %r',
+                    uri, sp_link.type)
+                return []
+        except RuntimeError as exc:
+            logger.info('Failed to lookup "%s": %s', uri, exc)
             return []
 
     def _lookup_track(self, sp_link):

tests/test_library.py

@@ -57,6 +57,19 @@ def test_lookup_of_unhandled_uri(session_mock, provider, caplog):
         in caplog.text())
 
 
+def test_lookup_when_offline(session_mock, sp_track_mock, provider, caplog):
+    session_mock.get_link.return_value = sp_track_mock.link
+    sp_track_mock.link.as_track.return_value.load.side_effect = RuntimeError(
+        'Must be online to load objects')
+
+    results = provider.lookup('spotify:track:abc')
+
+    assert len(results) == 0
+    assert (
+        'Failed to lookup "spotify:track:abc": Must be online to load objects'
+        in caplog.text())
+
+
 def test_lookup_of_track_uri(session_mock, sp_track_mock, provider):
     session_mock.get_link.return_value = sp_track_mock.link