带有对象列表的模拟通用方法

Question

Below is my interface having 2 methods one accepting a single ICommand object and a second accepting a list of ICommand object.

My first method works properly but my second method is not getting called via Mock. But in the actual implementation it gets called.

Can someone suggest what am I missing?

public interface ICommandBus
{
    void Dispatch<TCommand>(TCommand command) where TCommand : ICommand;
    void Dispatch<TCommand>(IList<TCommand> commands) where TCommand : ICommand;
}

[Test]
public void Test_Should_Work()
{
    var commands = new List<ICommand>();
    var mockDispatcher = Container.Instance.RegisterMock<ICommandBus>();
    mockDispatcher.Setup(x => x.Dispatch(It.IsAny<ICommand>())).Callback<ICommand>(x => commands.Add(x));
    mockDispatcher.Setup(x => x.Dispatch(It.IsAny<IList<ICommand>>())).Throws(new Exception("Some Error"));

    var commandBus = SportsContainer.Resolve<ICommandBus>();

    var commandslist = new List<UpdateCommand>()
    {
        new UpdateCommand(),
        new UpdateCommand()
    };

    //first call is working 
    commandBus.Dispatch<UpdateCommand>(commandslist[0]);

    //its not working. expected should throw an exception. but nothing is happening. 
    commandBus.Dispatch<UpdateCommand>(commandslist);

}

Answer 1

Your test isn't testing any code from you, it's merely verifying that a loose mock works. You can't unittest an interface.

Your code doesn't throw, because you use a loose mock (the default) which doesn't do anything and just returns null for any non-setup call. You pass a List<UpdateCommand> to a call that's setup with It.IsAny<IList<ICommand>>() , which doesn't match, so your .Throws() is never executed but null is returned instead.

Don't mock the class under test, because then you're not testing anything at all.

So you want to test your implementation:

var dispatcher = new YourDispatcher():
dispatcher.Dispatch<UpdateCommand>(commandslist[0]);
dispatcher.Dispatch<UpdateCommand>(commandslist);

Answer 2

I was finally able to get what i need. I need to be specific in defining setup for ICommand and it worked.

[Test]
public void Test_Should_Work()
{
        var commands = new List<ICommand>();
        var mockDispatcher = Container.Instance.RegisterMock<ICommandBus>();
        mockDispatcher.Setup(x => x.Dispatch(It.IsAny<IList<UpdateCommand>>())).Throws(new Exception("Some Error"));

        var commandBus = SportsContainer.Resolve<ICommandBus>();

        var commandslist = new List<UpdateScheduleCommand>()
        {
            new UpdateCommand(),
            new UpdateCommand()
        };

        //first call is working 
        //commandBus.Dispatch<UpdateScheduleCommand>(commandslist[0]);

        //its Working now.
        commandBus.Dispatch(commandslist);

}