@yukiakai/events-async

Drop-in replacement for Node.js EventEmitter with async listener support.
Supports emitAsync (parallel) and emitSeries (sequential) execution of listeners, and is fully type-safe in TypeScript.
Works with both string and symbol event names.

Features

• Fully TypeScript type-safe (on, off)
• Async listeners supported
• emitAsync: run all listeners in parallel
• emitSeries: run listeners sequentially
• Supports string and symbol keys for events
• Compatible with Node.js EventEmitter API

Installation

npm install @yukiakai/events-async
# or
yarn add @yukiakai/events-async

Usage

import { EventEmitterAsync } from '@yukiakai/events-async';

const SYMBOL_EVENT = Symbol('symbolEvent');

interface MyEvents {
  hello: (name: string) => void | Promise<void>;
  count: (n: number) => void | Promise<void>;
  [SYMBOL_EVENT]: (msg: string) => void | Promise<void>;
}

const ee = new EventEmitterAsync<MyEvents>();

// Type-safe listener
ee.on('hello', async (name) => {
  console.log('Hello', name);
});

ee.on(SYMBOL_EVENT, (msg) => {
  console.log('Symbol event:', msg);
});

// Emit asynchronously (parallel)
await ee.emitAsync('hello', 'world');
await ee.emitAsync(SYMBOL_EVENT, 'ok');

// Emit sequentially (in order)
await ee.emitSeries('hello', 'world');

API

See docs: API Docs

on(event, listener)

Register a listener with type safety. event can be string or symbol.

off(event, listener)

Remove a listener (type-safe).

emitAsync(event, ...args)

Run all listeners in parallel, await completion.

emitSeries(event, ...args)

Run listeners in order, await completion.

Notes

• Supports both sync and async listeners.
• string | symbol keys fully supported.

Development

npm install
npm run build
npm run test
npm run lint

Changelog

See full release notes in CHANGELOG.md

License

MIT © Yuki Akai