Ember.js: "EventDispatcher should never be instantiated in fastboot mode. Please report this as an Ember bug."

[mdebbar]

Ember version: [email protected]

When the app runs on the server side, I’m hitting few service injection errors of this kind:

Attempting to inject an unknown injection: 'service:xyz'

After some digging with @krisselden, we found that there's an error thrown (and swallowed) earlier in EngineInstance's cloneParentDependencies() method. The error is:

EventDispatcher should never be instantiated in fastboot mode. Please report this as an Ember bug.

So here I am, reporting an Ember bug as the error told me 🙂

I did some more digging and found an explanation to the swallowing of the real error. The error happens during the boot of an engine. The engine's boot() method correctly returns a rejected promise because of that error. Then that promise is ignored and the app continues running as if nothing happened.

[mdebbar]

It seems like the issue was introduced by this commit. The event_dispatcher was moved from the registrations list to the singletons list. The difference being that registrations are only resolved at this point, but singletons are eagerly looked up and instantiated.

A possible fix would be to check if running in a server-side environment, don't add event_dispatcher:main to the singletons list.

[rwjblue]

Sorry for the delay here, but I finally got the fix submitted in https://github.com/emberjs/ember.js/pull/15695.