相关疑难解决方法(0)

我在使用NSubstitute几次时遇到了一个奇怪的问题,虽然我知道如何解决它,但我从来没有能够解释它.

我已经精心设计了证明问题的最低要求测试,它似乎与使用方法创建替代返回值有关.

public interface IMyObject
{
    int Value { get; }
}

public interface IMyInterface
{
    IMyObject MyProperty { get; }
}

[TestMethod]
public void NSubstitute_ReturnsFromMethod_Test()
{
    var sub = Substitute.For<IMyInterface>();

    sub.MyProperty.Returns(MyMethod());
}

private IMyObject MyMethod()
{
    var ob = Substitute.For<IMyObject>();
    ob.Value.Returns(1);
    return ob;
}

当我运行上面的测试时,我得到以下异常:

Test method globalroam.Model.NEM.Test.ViewModel.DelayedAction_Test.NSubstitute_ReturnsFromMethod_Test threw exception: 
NSubstitute.Exceptions.CouldNotSetReturnException: Could not find a call to return from.
Make sure you called Returns() after calling your substitute (for example: mySub.SomeMethod().Returns(value)).
If you substituted for a class rather than …