tests: Use empty tag cache in all local backend tests

tests/backends/local/events_test.py

@@ -1,8 +1,17 @@
+from mopidy import settings
 from mopidy.backends.local import LocalBackend
 
-from tests import unittest
+from tests import unittest, path_to_data_dir
 from tests.backends.base import events
 
 
 class LocalBackendEventsTest(events.BackendEventsTest, unittest.TestCase):
     backend_class = LocalBackend
+
+    def setUp(self):
+        settings.LOCAL_TAG_CACHE_FILE = path_to_data_dir('empty_tag_cache')
+        super(LocalBackendEventsTest, self).setUp()
+
+    def tearDown(self):
+        super(LocalBackendEventsTest, self).tearDown()
+        settings.runtime.clear()

tests/backends/local/playback_test.py

@@ -18,6 +18,7 @@ class LocalPlaybackControllerTest(PlaybackControllerTest, unittest.TestCase):
 
     def setUp(self):
         settings.BACKENDS = ('mopidy.backends.local.LocalBackend',)
+        settings.LOCAL_TAG_CACHE_FILE = path_to_data_dir('empty_tag_cache')
         super(LocalPlaybackControllerTest, self).setUp()
 
     def tearDown(self):

tests/backends/local/playlists_test.py

@@ -18,6 +18,14 @@ class LocalPlaylistsControllerTest(
 
     backend_class = LocalBackend
 
+    def setUp(self):
+        settings.LOCAL_TAG_CACHE_FILE = path_to_data_dir('empty_tag_cache')
+        super(LocalPlaylistsControllerTest, self).setUp()
+
+    def tearDown(self):
+        super(LocalPlaylistsControllerTest, self).tearDown()
+        settings.runtime.clear()
+
     def test_created_playlist_is_persisted(self):
         path = os.path.join(settings.LOCAL_PLAYLIST_PATH, 'test.m3u')
         self.assertFalse(os.path.exists(path))

tests/backends/local/tracklist_test.py

@@ -4,7 +4,7 @@ from mopidy import settings
 from mopidy.backends.local import LocalBackend
 from mopidy.models import Track
 
-from tests import unittest
+from tests import unittest, path_to_data_dir
 from tests.backends.base.tracklist import TracklistControllerTest
 from tests.backends.local import generate_song
 
@@ -16,6 +16,7 @@ class LocalTracklistControllerTest(TracklistControllerTest, unittest.TestCase):
 
     def setUp(self):
         settings.BACKENDS = ('mopidy.backends.local.LocalBackend',)
+        settings.LOCAL_TAG_CACHE_FILE = path_to_data_dir('empty_tag_cache')
         super(LocalTracklistControllerTest, self).setUp()
 
     def tearDown(self):

tests/backends/local/translator_test.py

@@ -5,9 +5,9 @@ from __future__ import unicode_literals
 import os
 import tempfile
 
-from mopidy.utils.path import path_to_uri
 from mopidy.backends.local.translator import parse_m3u, parse_mpd_tag_cache
 from mopidy.models import Track, Artist, Album
+from mopidy.utils.path import path_to_uri
 
 from tests import unittest, path_to_data_dir