我有一种情况,我在Presenter类中有一些逻辑,它根据输入派生值并将它们传递给Creator类.为了测试Presenter类中的逻辑,我想验证在调用Creator时是否遵守了正确的派生值.我想出了下面的例子,但是我不确定我是否喜欢这种方法：

[TestFixture]
public class WidgetCreatorPresenterTester
{
    [Test]
    public void Properly_Generates_DerivedName()
    {
        var widgetCreator = new Mock<IWidgetCreator>();
        widgetCreator.Setup(a => a.Create(It.IsAny<Widget>()))
                     .Callback((Widget widget) => 
                     Assert.AreEqual("Derived.Name",widget.DerivedName));
 
        var presenter = new WidgetCreatorPresenter(widgetCreator.Object);
        presenter.Save("Name");
 
        widgetCreator.Verify(a => a.Create(It.IsAny<Widget>()),Times.Once());
    }
}

我很担心,因为最后没有Verify调用,不能保证调用回调中的断言.另一种方法是在回调中设置局部变量：

[Test]
public void Properly_Generates_DerivedName()
{
    var widgetCreator = new Mock<IWidgetCreator>();
    Widget localWidget = null;
    widgetCreator.Setup(a => a.Create(It.IsAny<Widget>()))
        .Callback((Widget widget) => localWidget = widget);
 
    var presenter = new WidgetCreatorPresenter(widgetCreator.Object);
    presenter.Save("Name");
 
    widgetCreator.Verify(a => a.Create(It.IsAny<Widget>()),Times.Once());
    Assert.IsNotNull(localWidget);
    Assert.AreEqual("Derived.Name",localWidget.DerivedName);
}

我觉得这种方法不易出错,因为它更明确,并且更容易看到将调用Assert语句.一种方法比另一种更好吗？有没有更简单的方法来测试传递给我缺少的模拟的输入参数？

如果它有用,这是此示例的其余代码：

public class Widget
{
    public string Name { get; set; }
    public string DerivedName { get; set; }
}
 
public class WidgetCreatorPresenter
{
    private readonly IWidgetCreator _creator;
 
    public WidgetCreatorPresenter(IWidgetCreator creator)
    {
        _creator = creator;
    }
 
    public void Save(string name)
    {
        _creator.Create(
            new Widget { Name = name,DerivedName = GetDerivedName(name) });
    }
 
    //This is the method I want to test
    private static string GetDerivedName(string name)
    {
        return string.Format("Derived.{0}",name);
    }
}
 
public interface IWidgetCreator
{
    void Create(Widget widget);
}

编辑
我更新了代码,使我在问题中概述的第二种方法更容易使用.我将Setup / Verify中使用的表达式的创建拉成了一个单独的变量,所以我只需要定义一次.我觉得这种方法是我最熟悉的,它很容易设置并且失败并且有很好的错误信息.

[Test]
public void Properly_Generates_DerivedName()
{
    var widgetCreator = new Mock<IWidgetCreator>();
    Widget localWidget = null;
 
    Expression<Action<IWidgetCreator>> expressionCreate = 
        (w => w.Create(It.IsAny<Widget>()));
    widgetCreator.Setup(expressionCreate)
        .Callback((Widget widget) => localWidget = widget);
 
    var presenter = new WidgetCreatorPresenter(widgetCreator.Object);
    presenter.Save("Name");
 
    widgetCreator.Verify(expressionCreate,localWidget.DerivedName);
}