Once

events.once — a Promise that resolves with the event's args the first time it fires. Depends on the Promise<T[]> value fix.

import { EventEmitter, once } from 'events'

async function main(): Promise<void> {
  const ee = new EventEmitter<{ ready: [number] }>()
  setTimeout(() => { ee.emit('ready', 42) }, 0)
  const args = await once(ee, 'ready')
  console.log('ready fired with', args[0])
}
main()

View source on GitHubexamples/events/once.ts

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