emmi

WIP

Inspired by mitt, but with a large modification: listeners return a response to the emit caller.

When defining an event i emmi, you need to type it with an input and output field. Calling emit will return an Output[] value. Output can be anything you want.

Also added an onReply listener that receives the Input and Output[] result of an emit.

This enables some interesting patterns not possible with most event emitters.

Listeners

Listeners can return the Output type, or simply omit returning anything. For convenience, listeners that return undefined/void will not be added to the Output[] result of an emit.

Note that async functions that return undefined (Promise<undefined>) will be returned