Moq a base class function from a derived class

Question

I am new to Moq and I just watched the pluralsight video on Moqing so I felt empowered to go and write some tests. I have a Base Class let’s say Sheet which implements an in

Answer 1

Moq is for imitating a dependency or dependencies of your system under test so that you can isolate that from the rest of your application or externalities, not for replacing your system under test. It's not the right tool for what you are trying to do here.

Answer 2

If you change

var MockSheet = new Moq<Page>();

into

var MockSheet = new Moq<Page> { CallBase = true, };

your mock (which you can think of as a derived class of Page) will call the implementation from Page in the mock's own override of CreateSheet.

The default behavior (if you do not change CallBase) is for Moq to override every method and property it can, and use an empty implementation. Setting CallBase to true makes Moq call the Page implementation instead, like I said.

(Of course, use MockSheet.Setup(x => x.CreateDocSheet()).Callback(() => { /* something */ }) if you want CreateDocSheet to do something non-trivial.)

In the case where you removed the virtual modifier from CreateSheet, Moq can no longer override or mock this member. Think of it: How could Moq "mock" a non-virtual method? Therefore, the call bypasses Moq's class completely.