Question

In some of my unit tests I am trying to return the string passed as a parameter using Moq.

If I ask it to return a specified string such as “home.aspx” it will work.

var navMock = new Mock<INavigationService>();
navMock
    .Setup(x => x.GetUrlForSystem(It.IsAny<NavigationService.System>(), It.IsAny<string>()))
    .Returns("home.aspx");

However when asking it to return the parameter I receive a

System.Reflection.TargetParameterCountException : Parameter count
mismatch.

var navMock = new Mock<INavigationService>();
navMock
    .Setup(x => x.GetUrlForSystem(It.IsAny<NavigationService.System>(), It.IsAny<string>()))
    .Returns((string s) => s);

Answer 1

    var navMock = new Mock<INavigationService>();  
     navMock  
    .Setup(x => x.GetUrlForSystem(It.IsAny<NavigationService.System>(), It.IsAny<string>()))  
    .Returns((NavigationService.System n, string s) => s);