如果您稍后验证调用了这些方法,是否可以在回调中进行断言?这是确保我的模拟获得传递给它的预期参数的首选方法,还是应该在回调中设置局部变量并在该实例上执行断言?
我遇到的情况是,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 时是否观察到正确的派生值。我想出了下面的示例,但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,因为如果没有Verify
最后调用时,不能保证回调中的断言会被调用。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);
}
我觉得这种方法不太容易出错,因为它更明确,而且更容易看出Assert
声明将被调用。一种方法优于另一种方法吗?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?
如果有帮助,以下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);
}
EDIT
我更新了代码,以使问题中概述的第二种方法更易于使用。我将设置/验证中使用的表达式的创建拉入一个单独的变量中,因此我只需定义它一次。我觉得这种方法是我最满意的,它很容易设置,并且失败时会显示良好的错误消息。
[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, Times.Once());
Assert.IsNotNull(localWidget);
Assert.AreEqual("Derived.Name", localWidget.DerivedName);
}