fix: Error if Sound.getTotalPlaybackDuration called before load

CHANGELOG.md

@@ -138,6 +138,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fixed issue where `ex.Sound.getTotalPlaybackDuration()` would crash if not loaded, now logs friendly warning
 - Fixed issue where an empty constructor on `new ex.Label()` would crash
 - Fixed issue where pointer events did not work properly when using [[ScreenElement]]s
 - Fixed issue where debug draw was not accurate when using *AndFill suffixed [[DisplayMode]]s

src/engine/Resources/Sound/Sound.ts

@@ -309,6 +309,11 @@ export class Sound implements Audio, Loadable<AudioBuffer> {
   }
 
   public getTotalPlaybackDuration() {
+    if (!this.isLoaded()) {
+      this.logger.warnOnce(`Sound from ${this.path} is not loaded, cannot return total playback duration.` +
+      `Did you forget to add Sound to a loader? https://excaliburjs.com/docs/loaders/`);
+      return 0;
+    }
     return this.data.duration;
   }