fix styled ASS

tests/unit/test_media_descriptor_change_set.py

@@ -13,6 +13,7 @@ if str(SRC_ROOT) not in sys.path:
 
 from ffx.media_descriptor import MediaDescriptor  # noqa: E402
 from ffx.media_descriptor_change_set import MediaDescriptorChangeSet  # noqa: E402
+from ffx.attachment_format import AttachmentFormat  # noqa: E402
 from ffx.track_descriptor import TrackDescriptor  # noqa: E402
 from ffx.track_type import TrackType  # noqa: E402
 from ffx.i18n import set_current_language  # noqa: E402
@@ -436,6 +437,47 @@ class MediaDescriptorChangeSetTests(unittest.TestCase):
         self.assertNotIn("creation_time=", metadata_tokens)
         self.assertNotIn("BPS=", metadata_tokens)
 
+    def test_attachment_tracks_are_ignored_for_pattern_comparison(self):
+        context = {
+            "logger": get_ffx_logger(),
+            "config": StaticConfig({}),
+        }
+
+        source_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "current.ttf", "mimetype": "font/ttf"},
+        )
+        target_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "stored.ttf", "mimetype": "font/ttf"},
+        )
+        stale_target_track = TrackDescriptor(
+            index=1,
+            source_index=1,
+            sub_index=1,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "missing.ttf", "mimetype": "font/ttf"},
+        )
+
+        change_set = MediaDescriptorChangeSet(
+            context,
+            MediaDescriptor(track_descriptors=[target_track, stale_target_track]),
+            MediaDescriptor(track_descriptors=[source_track]),
+        )
+
+        self.assertEqual({}, change_set.getChangeSetObj())
+        self.assertEqual([], change_set.generateMetadataTokens())
+        self.assertEqual([], change_set.generateDispositionTokens())
+
     def test_normalization_can_be_disabled_per_context(self):
         context = {
             "logger": get_ffx_logger(),