message: returning promise to OfflineTest defers the callback of 'render'
diff: @@ -6,7 +6,9 @@ define(["Tone/core/Tone", "Tone/core/Offline", "helper/BufferTest", "Tone/core/M
  channels = channels || 1;
  return Offline(function(Transport){
  var testFn = callback(Transport);
  - if (testFn){
  + if (testFn instanceof Promise){
  + return testFn;
  + } else if (Tone.isFunction(testFn)){
  Transport.context.on("tick", function(){
  testFn(Transport.now());
  });
  