@wasdadeel/emitter

A tiny, strongly-typed event emitter for TypeScript projects.
Built to be minimal, predictable, and dependency-free.

Installation

npm install @wasdadeel/emitter
# or
yarn add @wasdadeel/emitter

Usage

import { createEventEmitter } from "@wasdadeel/emitter";

// define your event map
type Events = {
  message: string;
  count: number;
};

const emitter = createEventEmitter<Events>();

// subscribe
const off = emitter.on("message", (msg) => {
  console.log("Got message:", msg);
});

// emit
emitter.emit("message", "Hello world!");

// unsubscribe
off();

// once
emitter.once("count", (n) => {
  console.log("Count fired once:", n);
});

emitter.emit("count", 1);
emitter.emit("count", 2); // won't fire

API

createEventEmitter<T>()

Creates a typed event emitter.

The returned emitter has the following methods:

• on(event, listener): () => void

  Subscribe to an event. Returns an unsubscribe function.

• once(event, listener): () => void

  Subscribe to an event once. Automatically removed after first call.

  Returns a manual unsubscribe.

• off(event, listener): void

  Remove a listener previously added with on.

• offOnce(event, listener): void

  Remove a listener previously added with once.

• emit(event, payload): void

  Trigger all listeners for a given event.

Why?

• No dependencies
• Simple source code - copy/paste & customize & be happy