使用FakeItEasy声明事件已被引发

时间:2015-01-30 20:22:31

标签: .net unit-testing events mocking fakeiteasy

我可以执行以下操作来验证我的ErrorOccurred课程的Consumer事件是否已被提出:

using System;
using FakeItEasy;
using Microsoft.VisualStudio.TestTools.UnitTesting;

public interface IService
{
    event EventHandler SomethingBadHappened;
}

class Consumer
{
    private readonly IService service;

    public Consumer(IService service)
    {
        this.service = service;
        service.SomethingBadHappened += (sender, args) => RaiseErrorOccurred();
    }

    public event EventHandler ErrorOccurred;

    protected virtual void RaiseErrorOccurred()
    {
        var handler = ErrorOccurred;
        if (handler != null) handler(this, EventArgs.Empty);
    }
}

[TestClass]
public class UnitTest1
{
    [TestMethod]
    public void TestMethod1()
    {
        var service = A.Fake<IService>();
        var consumer = new Consumer(service);

        bool eventWasRaised = false;
        consumer.ErrorOccurred += (sender, args) => { eventWasRaised = true; };

        service.SomethingBadHappened += Raise.WithEmpty();

        Assert.IsTrue(eventWasRaised);
    }
}

我想知道是否有更多的“Mocking Framework-y”方式。像下面这样的东西会很好:

        var service = A.Fake<IService>();
        var consumer = new Consumer(service);

        service.SomethingBadHappened += Raise.WithEmpty();

        consumer.ErrorOccurred.MustHaveHappened(/*yada yada/*);

1 个答案:

答案 0 :(得分:7)

对于FakeItEasy对方法执行任何断言,该方法必须是可伪造的,并在假对象上定义。在这种情况下,consumer是一个真实的&#34;对象,所以FakeItEasy无法知道它是否有任何作用。

还有另一种选择,但它是否更多&#34; Mocking Framework-y&#34;是否有争议。但它可能会吸引你。

创建假(在这种情况下为handler)以收听ErrorOccurred方法:

[TestMethod]
public void TestMethod2()
{
    var service = A.Fake<IService>();
    var consumer = new Consumer(service);

    var handler = A.Fake<EventHandler>();
    consumer.ErrorOccurred += handler;

    service.SomethingBadHappened += Raise.WithEmpty();

    A.CallTo(()=>handler.Invoke(A<object>._, A<EventArgs>._)).MustHaveHappened();
}

通过这种方式,您可以查看handler是否被调用。可以进行简单的修改,以确保将呼叫设为specific number of timescertain arguments

当然,如果您不关心调用该方法的次数或参数,因为handler上只有一种感兴趣的方法,您可能会使用这个更简单的调用,它将匹配对处理程序的任何调用(可能是Invoke):

A.CallTo(handler).MustHaveHappened();