How to Moq methods that return "this"

c#, moq, unit-testing

Solution

Assuming that you are using `Moq`, you can simply `Setup` the mock to return itself:

var mock = new Mock<IService>();

mock.Setup(service => service.Configure()).Returns(mock.Object);

var testClass = new TestClass(mock.Object);

Then validate if the method returned what you expect:

Assert.AreEqual(mock.Object, testClass.DoStuff());

Problem

I have an interface ``` interface IService { IService Configure(); bool Run(); } ``` The "real" implementation does this: ``` class RealService : IService { public IService Configure() { return this; } public bool Run() { return true; } } ``` Using Moq to mock the service creates a default implementation of `Configure()` that returns `null`. Is there a way to setup methods in Moq that return the mocked instance?

Original source