events: add hasEventListener util for validate · nodejs/node@e87db6c
@@ -287,6 +287,12 @@ ObjectDefineProperty(EventEmitter, 'defaultMaxListeners', {
287287},
288288});
289289290+function hasEventListener(self, type) {
291+if (type === undefined)
292+return self._events !== undefined;
293+return self._events !== undefined && self._events[type] !== undefined;
294+}
295+290296ObjectDefineProperties(EventEmitter, {
291297kMaxEventTargetListeners: {
292298__proto__: null,
@@ -680,13 +686,11 @@ EventEmitter.prototype.removeListener =
680686function removeListener(type, listener) {
681687checkListener(listener);
682688683-const events = this._events;
684-if (events === undefined)
689+if (!hasEventListener(this, type))
685690return this;
686691692+const events = this._events;
687693const list = events[type];
688-if (list === undefined)
689-return this;
690694691695if (list === listener || list.listener === listener) {
692696this._eventsCount -= 1;
@@ -742,9 +746,9 @@ EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
742746 */
743747EventEmitter.prototype.removeAllListeners =
744748function removeAllListeners(type) {
745-const events = this._events;
746-if (events === undefined)
749+if (!hasEventListener(this))
747750return this;
751+const events = this._events;
748752749753// Not listening for removeListener, no need to emit
750754if (events.removeListener === undefined) {
@@ -789,14 +793,10 @@ EventEmitter.prototype.removeAllListeners =
789793};
790794791795function _listeners(target, type, unwrap) {
792-const events = target._events;
793-794-if (events === undefined)
796+if (!hasEventListener(target, type))
795797return [];
796798797-const evlistener = events[type];
798-if (evlistener === undefined)
799-return [];
799+const evlistener = target._events[type];
800800801801if (typeof evlistener === 'function')
802802return unwrap ? [evlistener.listener || evlistener] : [evlistener];