TypedEventEmitter

Type : type-only

The TypedEventEmitter is a type-only utility for creating an event emitter with a strongly typed interface in Node.js. It allows you to define the name of the events and their associated data types, making it easier to handle and manage events in your code.

Usage

import { EventEmitter } from 'node:events';

type MyEvents = {
  'success': undefined;
  'fail': {message: string, code: number};
};

const emitter = new EventEmitter() as TypedEventEmitter<MyEvents>;

emitter.on('success', () => {
  console.log('success');
});

emitter.on('fail', ({ message, code }) => {
  console.log(message, code);
});

emitter.emit('success', undefined);
emitter.emit('fail', { message: 'error', code: 500 });