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: nodejs#46523
yuzheng14 · Jun 29, 2023 · bec4fff · bec4fff
1 parent 0ffad8a
commit bec4fff
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/lib/events.js b/lib/events.js
@@ -845,7 +845,7 @@ 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);