fix: prevent instrumentation to run in test mode

harmony_composer/src/instrumentation.rs

@@ -23,9 +23,18 @@ static HARMONY_COMPOSER_EVENT_BUS: Lazy<broadcast::Sender<HarmonyComposerEvent>>
     });
 
 pub fn instrument(event: HarmonyComposerEvent) -> Result<(), &'static str> {
-    match HARMONY_COMPOSER_EVENT_BUS.send(event) {
-        Ok(_) => Ok(()),
-        Err(_) => Err("send error: no subscribers"),
+    #[cfg(not(test))]
+    {
+        match HARMONY_COMPOSER_EVENT_BUS.send(event) {
+            Ok(_) => Ok(()),
+            Err(_) => Err("send error: no subscribers"),
+        }
+    }
+
+    #[cfg(test)]
+    {
+        let _ = event; // Suppress the "unused variable" warning for `event`
+        Ok(())
     }
 }