@giapspzoo/event-emitter

A simple isomorphic, strongly typed event emitter for TypeScript and JavaScript.
It allows you to declare your event map once and get full IntelliSense and type-safety for all listeners and emitted events.

Why?

📦 Zero dependencies

⚡ Lightweight & isomorphic

🛡️ Full TypeScript support with inferred payloads

🔄 Simple API

Installation

npm i @giapspzoo/event-emitter

Basic example

import EventEmitter from "@giapspzoo/event-emitter";

// Define your event map.
type Events = {
  push: { pushedItem: string }; // event with payload
  clear: void; // event without payload
};

const emitter = new EventEmitter<Events>();

// Add event listeners.
emitter.on("push", ({ pushedItem }) => {
  console.log("Item pushed:", pushedItem);
});

emitter.on("clear", () => {
  console.log("Cleared!");
});

// Emit events according to their declared types.
emitter.emit("push", { pushedItem: "foo" });
emitter.emit("clear");

// Remove a single listener...
const onClear = () => console.log("Cleared!");
emitter.on("clear", onClear);
emitter.off("clear", onClear);

// ...or remove all attached listeners.
emitter.removeAllListeners();

API

on(event: string, handler: (payload: P | void) => void) => void

Registers a new event handler.

off(event: string, handler: (payload: P | void) => void) => void

Removes a previously registered handler.

emit(event: string, payload: P | void) => void

Emits an event.

removeAllListeners() => void

Clears all listeners for all events.

License

MIT