如何在Moq中修改传入参数的值

Question

I am writing the unit test using moq for a method which has a parameter passed by ref. I need to modify the value of that parameter after the method is called. I am trying using the Callback for Moq setup but it is not updating the value.

myMock = new Mock<IMyObject>();
Foo foo = null;
myMock.Setup(x => x.GetResult(It.IsAny<string>(), ref foo))
          .Returns("SUCCESS")
          .Callback(() => { foo = new Foo ();});

I seen similar question here but they are answered to use callback, but I get the value of foo as null always.

Answer 1

I was struggling with a similar issue for the past 12 hours and the only way I achieve the results is by manually inheriting and mocking the object.

In your case you can setup a fake object that inherits IMyObject and define it's .GetResult behavior to initialize a new Foo object and then return a "SUCCESS".

You can then use the NUnit api for asserts.