Type definition of `. once(type, listener)` should have listener as optional parameter

[abdatta]

In the type definition, we see:

promise-events/emitter.d.ts

Line 21 in b001fa2

once(type: TEventType, listener: TListener): Promise<any>;

It should be instead:

once(type: TEventType, listener?: TListener): Promise<any>;

since the listener parameter is optional as per documentation:

emitter.once(eventName)

Returns a Promise that is resolved once only after all listeners for the specified event have been called for the given event. (Any newListener event will be emitted.)

@yanickrochon Let me know if you agree. I'll raise a PR for the same.

[yanickrochon]

Sounds about right! I do not use TS, personally, so all these PR are for the community 😄

[abdatta]

Can you merge #23 then? Thank you 🙂

[yanickrochon]

Sorry, it's published!