EventEmitter.once() method

Like on but the listener will only be fired once and then it will be removed.

Signature

class EventEmitter {
  once<Key extends keyof EventsWithWildcard<Events>>(
    type: Key,
    handler: (
      event: EventsWithWildcard<Events>[Key],
      eventData: Key extends '*' ? Events[keyof Events] : never,
    ) => void,
  ): this;
}

Parameters

Parameter	Type	Description
type	Key	the event you'd like to listen to
handler	(event: EventsWithWildcard<Events>[Key], eventData: Key extends '*' ? Events[keyof Events] : never) => void	the handler function to run when the event occurs

Returns:

this

this to enable you to chain method calls.