Comment on attachment 8957143 [details] Bug 1444073 - Remove old-event-emitter usage from webAudioEditor; . https://reviewboard.mozilla.org/r/226080/#review232028 ::: devtools/client/webaudioeditor/test/head.js:219 (Diff revision 2) > + win.once(win.EVENTS.UI_SET_PARAM, onParamSetSuccess); > + win.once(win.EVENTS.UI_SET_PARAM_ERROR, onParamSetError); Since you use `once` here, no need to do `off` in the handlers. Right?

Comment on attachment 8957143 [details] Bug 1444073 - Remove old-event-emitter usage from webAudioEditor; . https://reviewboard.mozilla.org/r/226080/#review232028 > Since you use `once` here, no need to do `off` in the handlers. Right? If UI_SET_PARAM_ERROR is emitted, the listener on UI_SET_PARAM is still up (and vice-versa). Tis way we are sure to clean things up. Or am I missing something in "once" implementation ?

Comment on attachment 8957143 [details] Bug 1444073 - Remove old-event-emitter usage from webAudioEditor; . https://reviewboard.mozilla.org/r/226080/#review232028 > If UI_SET_PARAM_ERROR is emitted, the listener on UI_SET_PARAM is still up (and vice-versa). > Tis way we are sure to clean things up. > Or am I missing something in "once" implementation ? Oh I see what you're doing here. I have no idea how/when these events are fired. But you are right, if we expect one to be fired, then we need to unlisten from the other one when it happens. However here you do `off` both times on the same event.

Comment on attachment 8957143 [details] Bug 1444073 - Remove old-event-emitter usage from webAudioEditor; . https://reviewboard.mozilla.org/r/226080/#review232028 > Oh I see what you're doing here. I have no idea how/when these events are fired. But you are right, if we expect one to be fired, then we need to unlisten from the other one when it happens. However here you do `off` both times on the same event. ah, good catch !

Pushed by nchevobbe@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/a5579339a6dd Remove old-event-emitter usage from webAudioEditor; r=pbro.