Question

enter code here我有一个方法可以在该方法中抛出异常时记录错误。该方法在单例内是非静态的。

    public object MethodA()
    {
        try
        {
            //code
                             SomeObj.Print(); //updated
        }
        catch (Exception ex)
        {
            log.Error(ex);
        }
    }

下面的单元测试代码抛出NullreferenceException：

                    var fakeLogger = A.Fake<ILog>();

        MySingleton.Instance.Initialize(fakeLogger);

        A.CallTo(() => MySingleton.Instance.MethodA()
            .Invokes((x) => { throw new Exception(); });
               //.Throws(new Exception()); --even this doesnt work
        A.CallTo(() => fakeLogger.Error(A<object>.Ignored)).MustHaveHappened();


Stack trace:
at FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyInterceptionValidator.GetReasonForWhyMethodCanNotBeIntercepted(MethodInfo method)
at FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyInterceptionValidator.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason)
at FakeItEasy.Creation.CastleDynamicProxy.CastleDynamicProxyGenerator.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason)
at FakeItEasy.Creation.ProxyGeneratorSelector.MethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget, String& failReason)
at FakeItEasy.Configuration.DefaultInterceptionAsserter.AssertThatMethodCanBeInterceptedOnInstance(MethodInfo method, Object callTarget)
at FakeItEasy.Configuration.FakeConfigurationManager.AssertThatMemberCanBeIntercepted(LambdaExpression callSpecification)
at FakeItEasy.Configuration.FakeConfigurationManager.CallTo(Expression`1 callSpecification)
at FakeItEasy.A.CallTo(Expression`1 callSpecification)

解决方案：我不得不让我的非假方法抛出异常，这就是我做的。

var fakeLogger = A.Fake<ILog>();
var someObject = A.Fake<SomeObject>();
MySingleton.Instance.Initialize(fakeLogger);
A.CallTo(() => someObject.Print()).Throws(new Exception()); //key
MySingleton.Instance.MethodA();
A.CallTo(() => fakeLogger.Error(A<object>.Ignored)).MustHaveHappened();

Answer 1

MySingleton.Instance并未指出您的假货，您伪造了ILog，而不是MySingleton，您只能在假货上配置方法。

例如：

A.CallTo(() => fakeLogger.MethodA()).Throws(new Exception());

你必须弄清楚在try catch-block中引发异常的其他方法。

Answer 2

试试这个：

A.CallTo(() => MySingleton.Instance.MethodA()).Throws(new Exception());
MySingleton.Instance.MethodA();
A.CallTo(() => fakeLogger.Error(A<object>.Ignored)).MustHaveHappened();

如果方法在该方法中引发异常时记录错误，则使用fake进行测试

2 个答案: