Class Emitter

packages/core/test/acceptance/change_detection_spec.ts:614–626

    it('should check parent OnPush components when child directive on a template emits event', async () => {
      @Directive({
        selector: '[emitter]',
        standalone: false,
      })
      class Emitter {
        @Output() event = new EventEmitter<string>();

        ngOnInit() {
          setTimeout(() => {
            this.event.emit('new message');
          });
        }
      }

      @Component({
        selector: 'my-app',