Implement event names function

EventEmitter2 · Mar 21, 2017 · ab1cdfb · ab1cdfb
1 parent 45256b0
commit ab1cdfb
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Showing 2 changed files with 24 additions and 8 deletions.
diff --git a/README.md b/README.md
@@ -328,3 +328,15 @@ Only this method doesn't work [IE](http://caniuse.com/#search=promise).
       console.log(results); // [3,2,1,0,undefined]
     });
 ```
+
+### emitter.eventNames()
+
+Returns an array listing the events for which the emitter has registered listeners. The values in the array will be strings.
+
+```javascript
+    emitter.on('foo', () => {});
+    emitter.on('bar', () => {});
+
+    console.log(emitter.eventNames());
+    // Prints: [ 'foo', 'bar' ]
+```
diff --git a/lib/eventemitter2.js b/lib/eventemitter2.js
@@ -24,7 +24,8 @@
       this._conf = conf;
 
       conf.delimiter && (this.delimiter = conf.delimiter);
-      this._events.maxListeners = conf.maxListeners !== undefined ? conf.maxListeners : defaultMaxListeners;
+      this._maxListeners = conf.maxListeners !== undefined ? conf.maxListeners : defaultMaxListeners;
+
       conf.wildcard && (this.wildcard = conf.wildcard);
       conf.newListener && (this.newListener = conf.newListener);
       conf.verboseMemoryLeak && (this.verboseMemoryLeak = conf.verboseMemoryLeak);
@@ -33,7 +34,7 @@
         this.listenerTree = {};
       }
     } else {
-      this._events.maxListeners = defaultMaxListeners;
+      this._maxListeners = defaultMaxListeners;
     }
   }
 
@@ -211,8 +212,8 @@
 
           if (
             !tree._listeners.warned &&
-            this._events.maxListeners > 0 &&
-            tree._listeners.length > this._events.maxListeners
+            this._maxListeners > 0 &&
+            tree._listeners.length > this._maxListeners
           ) {
             tree._listeners.warned = true;
             logPossibleMemoryLeak.call(this, tree._listeners.length, name);
@@ -236,8 +237,7 @@
 
   EventEmitter.prototype.setMaxListeners = function(n) {
     if (n !== undefined) {
-      this._events || init.call(this);
-      this._events.maxListeners = n;
+      this._maxListeners = n;
       if (!this._conf) this._conf = {};
       this._conf.maxListeners = n;
     }
@@ -568,8 +568,8 @@
       // Check for listener leak
       if (
         !this._events[type].warned &&
-        this._events.maxListeners > 0 &&
-        this._events[type].length > this._events.maxListeners
+        this._maxListeners > 0 &&
+        this._events[type].length > this._maxListeners
       ) {
         this._events[type].warned = true;
         logPossibleMemoryLeak.call(this, this._events[type].length, type);
@@ -734,6 +734,10 @@
     return this._events[type];
   };
 
+  EventEmitter.prototype.eventNames = function(){
+    return Object.keys(this._events);
+  }
+
   EventEmitter.prototype.listenerCount = function(type) {
     return this.listeners(type).length;
   };