我想对由被测类订阅的依赖项引发的事件进行单元测试。
为了设置上下文,我有以下接口(interface)和类。
ITestedService.cs
public interface ITestedService
{
Task Start();
Task Stop();
}
IDependency.cs
public interface IDependency
{
event EventHandler<SoAndSoEventArgs> SomethingHappened;
Task Start();
Task Stop();
}
ISecondDependency
public interface ISecondDependency
{
Task DoYourJob(SoAndSo soAndSo);
}
测试服务.cs
public class TestedService : ITestedService
{
readonly IDependency m_dependency;
readonly ISecondDependency m_secondDependency;
public TestedService(
IDependency dependency,
ISecondDependency secondDependency)
{
m_dependency = dependency;
m_secondDependency = secondDependency;
}
public async Task Start()
{
m_dependency.SomethingHappened += OnSomethingHanppened;
await m_dependency.Start();
}
private async void OnSomethingHanppened(object sender, SoAndSoEventArgs args)
{
SoAndSo soAndSo = SoAndSoMapper.MapToDTO(args);
await m_secondDependency.DoYourJob(soAndSo),
}
}
有了上面的上下文,我想对
Start()
进行单元测试TestedService
的方法使用 xUnit
的类.我想知道我该怎么做:
IDependency.SomethingHappened
被解雇。 OnSomethingHappened
方法执行ISecondDependency.DoYourJob(soAndSo)
叫做。 最佳答案
来自 this answer , this documentation根据@ZevSpitz 在评论中的指导,我能够为 Start() 编写以下测试。
虽然我无法验证相同的代码路径 OnSomethingHappened
被执行或者是其他一些调用 m_secondDependencyMock.DoYourJob(soAndSo)
的订阅.
TestedServiceTest.cs
public class TestedServiceTest
{
readonly Mock<IDependency> m_dependencyMock;
readonly Mock<ISecondDependency> m_secondDependencyMock;
ITestedService testedService;
public TestedServiceTest()
{
m_dependencyMock = new Mock<IDependency>();
m_secondDependencyMock = new Mock<ISecondDependency>();
testedService = new TestedService(m_dependencyMock.Object, m_secondDependencyMock.Object);
}
[Fact]
public async Start_DependencyStartInvoked()
{
// Arrange
m_dependencyMock.Setup(x=> x.Start()).Verifyable();
// Act
await testedService.Start();
// Assert
//This tests if the IDependecy.Start is invoked once.
m_dependencyMock.Verify(x=>x.Start(), Times.Once);
}
[Fact]
public async Start_EventListenerAttached()
{
// Arrange
m_dependencyMock.Setup(x=> x.Start()).Verifyable();
m_dependencyMock.SetupAdd(m => m.SomethingHappened += (sender, args) => { });
// Act
await testedService.Start();
// Assert
// The below together with SetupAdd above asserts if the TestedService.Start adds a new eventlistener
// for IDependency.SomethingHappened
m_dependencyMock.VerifyAdd(
m => m.SomethingHappened += It.IsAny<EventHandler<SoAndSoEventArgs>>(),
Times.Exactly(1));
}
[Fact]
public async Start_SomthingHappenedInvoked_HandlerExecuted()
{
// Arrange
m_dependencyMock.Setup(x=> x.Start()).Verifyable();
m_secondDependencyMock.Setup(x=> x.DoYourJob(It.IsAny<SoAndSo>())).Verifyable();
// Act
await testedService.Start();
// This will fire the event SomethingHappened from m_dependencyMock.
m_dependencyMock.Raise(m => m.SomethingHappened += null, new SoAndSoEventArgs());
// Assert
// Assertion to check if the handler does its job.
m_secondDependencyMock.Verify(x=> x.DoYourJob(It.IsAny<SoAndSo>()), Times.Once);
}
}
关于c# - 如何使用 xUnit 对 C# 事件进行单元测试,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59312203/