npm install @servie/events --save

import { Emitter, once } from "@servie/events";

// Define an events interface using keys & argument tuples.
interface Events {
  test: [boolean];
  other: [string];
}

// Initialize an `Emitter` using your `Events` interface.
const events = new Emitter<Events>();

// Add or remove listeners.
const listener = (...args) => console.log(args);
events.on("test", listener);
events.off("test", listener);

// Emit an event.
events.emit("test", true);

// Listen to _all_ events, e.g. debugging.
const eachListener = ({ type, args }) => console.log(type, args);
events.each(eachListener);
events.none(eachListener);

// "Once" utility.
const onceListener = (...args) => console.log(args);
once(events, "test", onceListener);