fix(lib/utils): fixes incorrect behaviour when re-adding the same event listener fn

Matthew Hill · vicb · commit 1b804cfeb1b8 · 2015-09-11T08:29:21.000-07:00
diff --git a/lib/utils.js b/lib/utils.js
@@ -115,7 +115,8 @@ function patchEventTargetMethods(obj) {
 
       handler[originalFnKey] = fn;
       handler[boundFnsKey] = handler[boundFnsKey] || {};
-      arguments[1] = handler[boundFnsKey][eventType] = zone.bind(fn);
+      handler[boundFnsKey][eventType] = handler[boundFnsKey][eventType] || zone.bind(fn);
+      arguments[1] = handler[boundFnsKey][eventType];
     }
     return global.zone.addEventListener.apply(this, arguments);
   };
diff --git a/test/patch/element.spec.js b/test/patch/element.spec.js
@@ -84,6 +84,32 @@ describe('element', function () {
     expect(eventListener.handleEvent).not.toHaveBeenCalled();
   });
 
+
+  it('should only add a listener once for a given set of arguments', function() {
+    var log = [];
+    var clickEvent = document.createEvent('Event');
+
+    function listener() {
+      log.push('listener');
+    }
+
+    clickEvent.initEvent('click', true, true);
+
+    button.addEventListener('click', listener);
+    button.addEventListener('click', listener);
+    button.addEventListener('click', listener);
+
+    button.dispatchEvent(clickEvent);
+
+    button.removeEventListener('click', listener);
+
+    button.dispatchEvent(clickEvent);
+
+    expect(log).toEqual([
+        'listener'
+    ]);
+  });
+
   it('should correctly handle capturing versus nonCapturing eventListeners', function () {
     var log = [];
     var clickEvent = document.createEvent('Event');

Original file line number	Diff line number	Diff line change
`@@ -115,7 +115,8 @@ function patchEventTargetMethods(obj) {`
`115`	`115`
`116`	`116`	`handler[originalFnKey] = fn;`
`117`	`117`	`handler[boundFnsKey] = handler[boundFnsKey] \|\| {};`
`118`		`- arguments[1] = handler[boundFnsKey][eventType] = zone.bind(fn);`
	`118`	`+ handler[boundFnsKey][eventType] = handler[boundFnsKey][eventType] \|\| zone.bind(fn);`
	`119`	`+ arguments[1] = handler[boundFnsKey][eventType];`
`119`	`120`	`}`
`120`	`121`	`return global.zone.addEventListener.apply(this, arguments);`
`121`	`122`	`};`