Adjust test, make it extra-clear when we're missing something

src/backend/mod.rs

@@ -207,7 +207,11 @@ impl From<CAChannelLabel> for mixer::Channel {
             sys::kAudioChannelLabel_TopBackCenter => mixer::Channel::TopBackCenter,
             sys::kAudioChannelLabel_TopBackRight => mixer::Channel::TopBackRight,
             sys::kAudioChannelLabel_Unknown => mixer::Channel::Discrete,
-            _ => panic!("Label not handled"),
+            sys::kAudioChannelLabel_Unused => mixer::Channel::Silence,
+            v => {
+                eprintln!("Warning: channel label value {} isn't handled", v);
+                mixer::Channel::Silence
+            }
         }
     }
 }

src/backend/tests/api.rs

@@ -376,7 +376,6 @@ fn test_get_default_device_id_with_inout_type() {
 #[test]
 fn test_convert_channel_layout() {
     let pairs = [
-        (vec![kAudioObjectUnknown], vec![mixer::Channel::Silence]),
         (
             vec![kAudioChannelLabel_Mono],
             vec![mixer::Channel::FrontCenter],
@@ -398,7 +397,7 @@ fn test_convert_channel_layout() {
             vec![
                 mixer::Channel::FrontLeft,
                 mixer::Channel::FrontRight,
-                mixer::Channel::Silence,
+                mixer::Channel::Discrete,
             ],
         ),
         (