events: fix bug listenerCount don't compare wrapped listener

When add listener by once, it will be wrapped into another function. And when pass listener and there is just one event listener added by once, it will return 0 even if passed listener equal wrapped event listener. Refs: #46523 PR-URL: #48592 Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Paolo Insogna <[email protected]> Reviewed-By: Minwoo Jung <[email protected]>
nodejs · Sep 11, 2023 · 6e2cbe0 · 6e2cbe0
1 parent cb2e22c
commit 6e2cbe0
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diff --git a/lib/events.js b/lib/events.js
@@ -850,7 +850,7 @@ function listenerCount(type, listener) {
 
     if (typeof evlistener === 'function') {
       if (listener != null) {
-        return listener === evlistener ? 1 : 0;
+        return listener === evlistener || listener === evlistener.listener ? 1 : 0;
       }
 
       return 1;

diff --git a/test/parallel/test-events-listener-count-with-listener.js b/test/parallel/test-events-listener-count-with-listener.js
@@ -12,6 +12,18 @@ assert.strictEqual(EE.listenerCount('event'), 0);
 assert.strictEqual(EE.listenerCount('event', handler), 0);
 assert.strictEqual(EE.listenerCount('event', anotherHandler), 0);
 
+EE.once('event', handler);
+
+assert.strictEqual(EE.listenerCount('event'), 1);
+assert.strictEqual(EE.listenerCount('event', handler), 1);
+assert.strictEqual(EE.listenerCount('event', anotherHandler), 0);
+
+EE.removeAllListeners('event');
+
+assert.strictEqual(EE.listenerCount('event'), 0);
+assert.strictEqual(EE.listenerCount('event', handler), 0);
+assert.strictEqual(EE.listenerCount('event', anotherHandler), 0);
+
 EE.on('event', handler);
 
 assert.strictEqual(EE.listenerCount('event'), 1);