Angular / Jasmine服务中的模拟服务

Question

在这个Angular / Jasmine代码中，我有一个控制器和两个服务，service1和service2。控制器调用service1和service1来电service2。

我试图在对控制器进行单元测试时模拟service2，而不是模仿service1。这可能吗？

这是plunk中我的尝试（不起作用）：

angular.module("myModule", [])

.service('service1', function(service2){
    this.sum = function(num1,num2) {
        return service2.theRealSum(num1,num2);
    };
})

.service('service2', function(){
    this.theRealSum = function(num1,num2) {
        return num1 + num2;
    };
})


.controller('ctl', function($scope,$timeout,service1) {
      $scope.sumTheTwo = function (num1,num2){
        $scope.result = service1.sum(num1,num2);
    };
});



describe('Testing a Controller that sums', function () {
  var $scope;

  beforeEach(module('myModule'));

  beforeEach(inject(function($controller, _$rootScope_, service1,service2) {
    $scope = _$rootScope_.$new();
    spyOn(service2, 'theRealSum');

    $controller('ctl', { 
      $scope: $scope, 
      service1: service1
    });

  }));

  it('should resolve promise', function () {
    $scope.sumTheTwo(1,2);
    $scope.$apply();
    expect($scope.result).toBe(3);
  });

});