spit
Spit is an event emitter that leverages asynchronous methods.
There are two key differences between it and the node.js core event emitter.
The emit() method returns a promise that will be resolved or rejected when all listeners have completed.
The on() or addListener() method accepts two parameters, an event name and a method that will receive all arguments that were emitted on that event. You may return a promise within the method if you need to do any asynchronous processing.