Refactored decorator into a factory so that we can test that the delegate is called

Author: petebacondarwin

src/common/services/exceptionHandler.js

@@ -1,15 +1,27 @@
-angular.module('services.exceptionHandler', ['services.notifications', 'services.localizedMessages'], ['$provide', function($provide) {
-
-  $provide.decorator('$exceptionHandler',  ['$injector', '$delegate', 'localizedMessages', function ($injector, $delegate, localizedMessages) {
+angular.module('services.exceptionHandler', ['services.notifications', 'services.localizedMessages']);
 
+angular.module('services.exceptionHandler').factory('exceptionHandlerFactory', ['$injector', 'localizedMessages', function($injector, localizedMessages) {
+  return function($delegate) {
+    var notifications;
     return function (exception, cause) {
-      //need to get the notications service from injector due to circular dependencies:
+      // Lazy load notifications to get around circular dependency
       //Circular dependency: $rootScope <- notifications <- $exceptionHandler
+      var notifications = notifications || $injector.get('notifications');
+
+      // Pass through to original handler
       $delegate(exception, cause);
-      $injector.get('notifications').pushForCurrentRoute(localizedMessages.get('error.fatal'), 'error', {
+
+      // Push a notification error
+      notifications.pushForCurrentRoute(localizedMessages.get('error.fatal'), 'error', {
         exception:exception,
         cause:cause
       });
     };
+  };
+}]);
+
+angular.module('services.exceptionHandler').config(['$provide', function($provide) {
+  $provide.decorator('$exceptionHandler', ['$delegate', 'exceptionHandlerFactory', function ($delegate, exceptionHandlerFactory) {
+    return exceptionHandlerFactory($delegate);
   }]);
 }]);

test/unit/common/services/exceptionHandlerSpec.js

@@ -36,4 +36,16 @@ describe('exception handler', function () {
       $exceptionHandler(new Error('root cause'));
     }).toThrow('issue with notifications');
   });
+
+  it('should call through to the delegate', function() {
+    inject(function(exceptionHandlerFactory) {
+      var error = new Error('Something went wrong...');
+      var cause = 'Some obscure problem...';
+
+      var delegate = jasmine.createSpy('delegate');
+      var exceptionHandler = exceptionHandlerFactory(delegate);
+      exceptionHandler(error, cause);
+      expect(delegate).toHaveBeenCalledWith(error, cause);
+    });
+  });
 });