On

events.on — an async iterator that yields the event's args array on each emission, buffering events between iterations and parking the consumer when the queue drains. The listener is attached eagerly at the on(...) call.

import { EventEmitter, on } from 'events'

async function main(): Promise<void> {
  const ee = new EventEmitter<{ tick: [number] }>()

  // Emit from a timer, after the loop below has started and parked.
  let sent = 0
  const timer = setInterval(() => {
    sent++
    ee.emit('tick', sent)
  }, 10)

  let count = 0
  for await (const [n] of on(ee, 'tick')) {
    console.log('tick', n)
    count++
    if (count >= 3) {
      clearInterval(timer)
      break
    }
  }
  console.log('done after', count, 'ticks')
}
main()

View source on GitHubexamples/events/on.ts

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