Cloudflare Docs
Workers
Cloudflare Docs
Workers
GitHub icon
Visit Workers on GitHub
Set theme to dark (⇧+D)
  1. Products
  2. Workers
  3. ...
  4. Node.js compatibility
  5. EventEmitter

EventEmitter

An EventEmitter is an object that emits named events that cause listeners to be called.


import { EventEmitter } from 'node:events';



const emitter = new EventEmitter();
emitter.on('hello', (...args) => {
  console.log(...args);

});


emitter.emit('hello', 1, 2, 3);

The implementation in the Workers runtime fully supports the entire Node.js EventEmitter API. This includes the captureRejections option that allows improved handling of async functions as event handlers:


const emitter = new EventEmitter({ captureRejections: true });
emitter.on('hello', async (...args) => {
  throw new Error('boom');

});
emitter.on('error', (err) => {
  // the async promise rejection is emitted here!

});

Refer to the Node.js documentation for EventEmitter for more information.