How to check if anyone is subscribed to EventEmitter in Angular?

There is a EventEmitter:

@Output() edit: EventEmitter<any> = new EventEmitter();

How to check if anyone is subscribed to EventEmitter in Angular?

Angular EventEmitter is an RXJS Subject:

class EventEmitter<T> extends Subject<T>

Check if any subscribers/observers

Subject.observed: bool -- true if there are 1 or more subscribers

RXJS Source Code

/**
 * A Subject is a special type of Observable that allows values to be
 * multicasted to many Observers. Subjects are like EventEmitters.
 *
 * Every Subject is an Observable and an Observer. You can subscribe to a
 * Subject, and you can call next to feed values as well as error and complete.
 */
export class Subject<T> extends Observable<T> implements SubscriptionLike {
  ...

  private currentObservers = new Map<number, Observer<T>>()

  get observed() {
    return this.currentObservers.size > 0;
  }

Notes

• Rather than using an EventEmitter, consider BehaviorSubject or ReplaySubject.

See: Delegation: EventEmitter or Observable in Angular