单元测试：从嵌套类型引发事件

Question

我有一个接口，在另一个接口上有一个属性，

public interface IInnerInterface
{
    event EventHandler OnCompleted;
}

public class InnerClassImplementation : IInnerInterface
{
    public event EventHandler OnCompleted;

    private void CompletedState()
    {
        OnCompleted?.Invoke(this, new EventArgs());
    }
}

public interface IOuterInterface
{
    IInnerInterface InnerInterface { get; }
}

public class Main : IOuterInterface
{
    public IInnerInterface InnerInterface { get; }

    public bool IsOperationComplete { get; set; }

    public Main(IInnerInterface innerInterface)
    {
        InnerInterface = innerInterface;
        InnerInterface.OnCompleted += InnerInterface_OnCompleted;
    }

    private void InnerInterface_OnCompleted(object sender, EventArgs e)
    {
        IsOperationComplete = true;
    }
}

我正在尝试测试 Main class。测试用例之一是验证事件的处理程序方法。

我尝试了下面的代码实现来测试，

[TestClass]
public class MainTest
{
    private Mock<IInnerInterface> _innerInterfaceMock;
    private Main _main;

    [TestInitialize]
    public void Initialize()
    {
        _innerInterfaceMock = new Mock<IInnerInterface>();
        _main = new Main(_innerInterfaceMock.Object);
    }

    [TestMethod]
    public void OnCompleted_ShouldDoSomething()
    {
        //Act
        _main.Raise(m=>m.InnerInterface.OnCompleted+=null, new EventArgs());

        //Assert
        _main.IsOperationComplete.Should().BeTrue();

    }
}

我收到以下错误，

Test method Samples.MainTest.OnCompleted_ShouldDoSomething threw exception: Telerik.JustMock.Core.MockException: Unable to deduce which event was specified in the parameter. at Telerik.JustMock.Core.Behaviors.RaiseEventBehavior.RaiseEventImpl(Object instance, EventInfo evt, Object[] args) at Telerik.JustMock.Core.ProfilerInterceptor.GuardInternal(Action guardedAction) at Samples.MainTest.OnCompleted_ShouldDoSomething()

不知道我做错了什么？

Answer 1

你不应该从你的 SUT (Main) 引发事件，直接从 IInnerInterface 模拟引发它：

_innerInterfaceMock.Raise(o => o.OnCompleted+=null, new EventArgs());

顺便说一下，此代码（基于您的代码）使用 moq 而不是 justmock 但您的异常与 justmock 相关，我假设同时使用这两种方法会导致方法和重载混淆，只是选择一个并坚持下去。

单元测试：从嵌套类型引发事件

Unit Testing : Raise Event From Nested Type

c#

unit-testing

justmock