fix(addEventListener): when called from the global scope

fixes #190

Author: vicb

lib/utils.js

@@ -110,15 +110,18 @@ function patchEventTargetMethods(obj) {
         })(handler);
       } else {
         fn = handler;
-      } 
+      }
 
       handler[originalFnKey] = fn;
       handler[boundFnsKey] = handler[boundFnsKey] || {};
       handler[boundFnsKey][eventType] = handler[boundFnsKey][eventType] || zone.bind(fn);
       arguments[1] = handler[boundFnsKey][eventType];
     }
 
-    var target = isWebWorker() && !this ? self : this;
+    // - Inside a Web Worker, `this` is undefined, the context is `global` (= `self`)
+    // - When `addEventListener` is called on the global context in strict mode, `this` is undefined
+    // see https://github.com/angular/zone.js/issues/190
+    var target = this || global;
 
     return global.zone.addEventListener.apply(target, arguments);
   };
@@ -129,11 +132,15 @@ function patchEventTargetMethods(obj) {
     var eventType = eventName + (useCapturing ? '$capturing' : '$bubbling');
     if (handler[boundFnsKey] && handler[boundFnsKey][eventType]) {
       var _bound = handler[boundFnsKey];
-      
       arguments[1] = _bound[eventType];
       delete _bound[eventType];
     }
-    var target = isWebWorker() && !this ? self : this;
+
+    // - Inside a Web Worker, `this` is undefined, the context is `global`
+    // - When `addEventListener` is called on the global context in strict mode, `this` is undefined
+    // see https://github.com/angular/zone.js/issues/190
+    var target = this || global;
+
     var result = global.zone.removeEventListener.apply(target, arguments);
     global.zone.dequeueTask(handler[originalFnKey]);
     return result;

test/patch/element.spec.js

@@ -14,6 +14,35 @@ describe('element', function () {
     document.body.removeChild(button);
   });
 
+  // https://github.com/angular/zone.js/issues/190
+  it('should work when addEventListener / removeEventListener are called in the global context', function () {
+    var clickEvent = document.createEvent('Event');
+    var callCount = 0;
+
+    clickEvent.initEvent('click', true, true);
+
+    var listener = function (event) {
+      callCount++;
+      expect(zone).toBeDirectChildOf(testZone);
+      expect(event).toBe(clickEvent)
+    };
+
+    testZone.run(function() {
+      // `this` would be null inside the method when `addEventListener` is called from strict mode
+      // it would be `window`:
+      // - when called from non strict-mode,
+      // - when `window.addEventListener` is called explicitely.
+      addEventListener('click', listener);
+    });
+
+    button.dispatchEvent(clickEvent);
+    expect(callCount).toEqual(1);
+
+    removeEventListener('click', listener);
+    button.dispatchEvent(clickEvent);
+    expect(callCount).toEqual(1);
+  });
+
   it('should work with addEventListener when called with a function listener', function () {
     var clickEvent = document.createEvent('Event');
     clickEvent.initEvent('click', true, true);