Verifying protected abstract methods are called using Moq

Question

Suppose I have the following class:

public class TestBase
{
  public bool runMethod1 { get; set; }

  public void BaseMethod() 
  {
    if (runMethod1)
      ChildMethod1();
    else 
      ChildMethod2();
  }

  protected abstract void ChildMethod1();
  protected abstract void ChildMethod2();
}

I also have the class

public class ChildTest : TestBase
{
  protected override void ChildMethod1()
  {
    //do something
  } 

  protected override void ChildMethod2()
  {
    //do something completely different
  }

}

I'm using Moq, and I'd like to write a test that verifies ChildMethod1() is being called when I call BaseMethod() and runMethod1 is true. Is it possible to create an implemention of TestBase with Moq, call BaseMethod() and verify that ChildMethod was called on the Moq implementation?

[Test]
public BaseMethod_should_call_correct_child_method()
{
  TestBase testBase;

  //todo: get a mock of TestBase into testBase variable

  testBase.runMethod1 = true;

  testBase.BaseMethod();

  //todo: verify that ChildMethod1() was called

}

Answer 1

You can also set the expectation/setup as Verifiable and do without a strict mock:

  //expect that ChildMethod1() will be called once. (it's protected)
  testBaseMock.Protected().Expect("ChildMethod1")
    .AtMostOnce()
    .Verifiable();

  ...

  //make sure the method was called
  testBase.Verify();

Edit This syntax does not work in current versions of Moq. See this question for how to do it as of at least 4.0.10827

Answer 2

I figured out how to do this. You can can mock protected methods with Moq, and by making a strict mock, you can verify that they were called. Now I can test the base class without having to make any subclasses.

[Test]
public BaseMethod_should_call_correct_child_method()
{
  //strict mocks will make sure all expectations are met
  var testBaseMock = new Mock<TestBase>(MockBehavior.Strict);

  //expect that ChildMethod1() will be called once. (it's protected)
  testBaseMock.Protected().Expect("ChildMethod1")
    .AtMostOnce();

  var testBase = testBaseMock.Object;

  testBase.runMethod1 = true;
  testBase.BaseMethod();

  //make sure the method was called
  testBase.VerifyAll();
}