Why am I getting an Exception with the message “Invalid setup on a non-virtual (overridable in VB) member…”?

Question

I have a unit test where I have to mock a non-virtual method that returns a bool type

public class XmlCupboardAccess
{
    public bool IsDataEntityInXmlCupbo         


        

Answer 1

Instead of mocking concrete class you should mock that class interface. Extract interface from XmlCupboardAccess class

public interface IXmlCupboardAccess
{
    bool IsDataEntityInXmlCupboard(string dataId, out string nameInCupboard, out string refTypeInCupboard, string nameTemplate = null);
}

And instead of

private Mock _xmlCupboardAccess = new Mock();

change to

private Mock _xmlCupboardAccess = new Mock();