Rhino Mocks未抛出异常

Question

我试图从测试中抛出一个异常(使用rhino和nunit)，但它不能像预期的那样工作

接口

public interface IEmailService
{
    void SendEmail(string to, string subject, string body);
}

public interface IWebService
{
    void LogError(string message);
}

类

public class MockService : IWebService
{
    public string LastError;

    public void LogError(string message)
    {
        LastError = message;
    }
}

public class LogAnalyzerDynamicMockWithEmail
{
    public  IWebService Service { get; set; }
    public IEmailService Email { get; set; }

    public void Analyze(string fileName)
    {
        try
        {
            if (fileName.Length < 8)
                Service.LogError("Filename too short:" + fileName);
        }
        catch (Exception exception)
        {
            Email.SendEmail("a", "subject", exception.Message);
        }
    }
}

这是测试方法

[Test]
    public void Analyze_WebServiceThrows_SendsEmail()
    {
        var mockRepository = new MockRepository();
        var stubWebService = mockRepository.Stub<IWebService>();
        var mockEmailService = mockRepository.StrictMock<IEmailService>();

        var logAnalyzerDynamicMockWithEmail = new LogAnalyzerDynamicMockWithEmail
        {
            Service = stubWebService,
            Email = mockEmailService
        };

        stubWebService.Stub(m => m.LogError("whatever")).IgnoreArguments().Throw(new Exception("fake exception"));


        Assert.Throws<Exception>(() => { logAnalyzerDynamicMockWithEmail.Analyze("abc.ext"); });
        mockEmailService.AssertWasCalled(m => m.SendEmail("a", "subject", "fake exception"));

    }

但是测试失败了，消息是"Expected: <system.exception>, but was: null“

有人能帮我指出我这里遗漏了什么吗？

Answer 1

我不确定为什么您的模拟没有抛出异常，但我建议使用较新的RhinoMock语法(不需要实例化MockRepository)。此外，您的Assert.Throws调用将不起作用，因为您的代码正在捕获异常。只有当异常未被捕获时，Assert.Throws才有用。

下面是一个有效的示例。请注意，我将SendEmail期望移到了Analyze调用之上。不管mock上的期望值有多少，调用VerifyAllExpectations将确保它们得到满足。

[Test]
public void Analyze_WebServiceThrows_SendsEmail_Modified()
{
    var stubWebService = MockRepository.GenerateMock<IWebService>();
    var mockEmailService = MockRepository.GenerateMock<IEmailService>();

    var logAnalyzerDynamicMockWithEmail = new LogAnalyzerDynamicMockWithEmail
    {
        Service = stubWebService,
        Email = mockEmailService
    };

    // Set up our expectations
    stubWebService.Expect(m => m.LogError("whatever")).IgnoreArguments().Throw(new Exception("fake exception"));
    mockEmailService.Expect(m => m.SendEmail("a", "subject", "fake exception")).Repeat.Once();

    logAnalyzerDynamicMockWithEmail.Analyze("abc.ext");

    // Verify our SendEmail method was called
    mockEmailService.VerifyAllExpectations();
}

Answer 2

您的.Analyze()方法正在捕获异常，而不是重新抛出它，因此它永远不会返回到Assert.Thows()调用。

catch (Exception exception)
{
    Email.SendEmail("a", "subject", exception.Message);
}

因此，您的测试正确地失败了。对Analyze()的调用不会引发异常。相反，它捕获由您的mock抛出的异常，发送一封电子邮件并继续。如果你想让它抛出，你需要在你的catch块中重新抛出异常，如下所示：

catch (Exception exception)
{
     Email.SendEmail("a", "subject", exception.Message);
     throw;
}