如何在返回之前修改模拟对象上方法调用的结果？

Question

考虑下面的流线型例如，使用RhinoMocks和MSpec：

[Subject(typeof (LocationController))] 
public class when_creating_a_location_with_invalid_model : context_for_location_controller 
{ 
    static LocationModel model = new LocationModel(); 
    static SelectList states = new SelectList(new Dictionary<string,string> { 
     { "IN", "Indiana" }, { "NY", "New York" } 
    }); 

    static ActionResult result; 

    Establish context =() => 
     { 
      LocationModelBuilder.Stub(x => 
       x.Build(Arg<LocationModel>.Is.Equal(model))).Return(model); 
     } 

    Because of =() => result = subject.Create(model); 

    It should_automatically_select_a_state =() => result.Model<LocationModel>() 
     .States.ShouldNotBeEmpty(); 
} 

如何修改包含在模型变量对象是从LocationModelBuilder.Build（）的存根调用返回前？我想在Build（）返回之前执行model.States = states之类的任务。我尝试使用Do（）处理程序，但我放弃了...

Answer 1

尝试使用WhenCalled（）。 WhenCalled的参数允许访问mocked方法的参数，您也可以设置返回值。

.WhenCalled(m => { 
    Model model = (Model) m.Arguments[0]; 
    model.States = ...; 
});