如何在AngularJS中测试Broadcast事件

Question

我有一个控制器在根镜上发出广播事件.我想测试broacast事件是否正确触发.

我的控制器中的代码如下所示:

   $scope.$watch("pageIndex", function(){
    if($scope.pageIndex == 4)
    {
      // emit social share
      $rootScope.$broadcast('myEvent');
    }
  });

我试图用以下代码测试它:

    it('Should call myEvent when pageIndex is 4',function(){
    scope.pageIndex = 4;
    scope.$apply();
    expect(rootScope.$on).toHaveBeenCalledWith('myEvent');
});

但是它告诉我代码没有被调用,我已经手动测试了它.然后我尝试使用以下代码:

it('Should call myEvent when pageIndex is 4',function(){
    var listener = jasmine.createSpy('listener');
    rootScope.$on('myEvent', listener);
    scope.pageIndex = 4;
    scope.$apply();
    expect(listener).toHaveBeenCalled();
});

但同样的负面结果.有没有办法测试一个事件是否被广播？

Answer 1

假设您正在使用Jasmine,以下内容对我来说非常有用.

... other unit test setup code ...

var rootScope;
beforeEach(inject(function($injector) {
    rootScope = $injector.get('$rootScope');
    spyOn(rootScope, '$broadcast');
}));

describe("my tests", function() {
    it("should broadcast something", function() {
        expect(rootScope.$broadcast).toHaveBeenCalledWith('myEvent');
    });
});

如果您正在广播消息并将对象附加到消息上,您甚至可以测试对象是否符合预期

someObj = { ... something ... };
expect(rootScope.$broadcast).toHaveBeenCalledWith('someEvent', someObj);

Answer 2

这是它如何用mochaJs完成的,其中sinon用于模拟和chai用于期望.

describe("broadcast test", function() {
  beforeEach(inject(function($rootScope){
   sinon.spy($rootScope, "$broadcast")
   scope.foo() //this broadcasts the event. $rootScope.$broadcast("testEvent")
 }))

it("broadcasts the event", inject(function($rootScope){
 expect($rootScope.$broadcast.calledWith("testEvent")).to.be.true
}))

})