Reset mock verification in Moq?

Question

Setup as so:

public interface IFoo
{
    void Fizz();
}

[Test]
public void A()
{
    var foo = new Mock(MockBehavior.Loose);

    foo.Object.Fizz();         


        

Answer 1

I don't think you can reset a mock like this. Instead, if you know that Fizz should be called once when transitioning to state 1, you can do your verifies like this:

objectUnderTest.DoStuffToPushIntoState1();
foo.Verify(x => x.Fizz(), Times.Once());  // or however many times you expect it to be called

objectUnderTest.DoStuffToPushIntoState2();
foo.Verify(x => x.Fizz(), Times.Once());

Having said that, I would still create two separate tests for this. As two tests, it's easier to see whether the transition into state 1 is failing, or the transition into state 2 is failing. Additionally, when tested together like this, if your transition into state 1 fails, the test method exits and your transition into state 2 doesn't get tested.

Edit

As an example of this, I tested the following code with xUnit:

[Fact]
public void Test()
{
    var foo = new Mock<IFoo>(MockBehavior.Loose);

    foo.Object.Fizz();
    foo.Verify(x => x.Fizz(), Times.Once(), "Failed After State 1");

    // stuff here
    foo.Object.Fizz();
    foo.Verify(x => x.Fizz(), Times.Once(), "Failed after State 2"); 
}

This test fails with the message, "Failed after State 2". This simulates what would happen if your method that pushes foo into State 2 calls Fizz. If it does, the second Verify will fail.

Looking at your code again, since you are calling one method to verify it does/does not call another method on the mock, I think you need to set CallBase to true so that the base DoStuffToPushIntoState2 is called rather than the mock's override.

Answer 2

I think long after this post was created they added the functionality that the OP had asked for, there is a Moq extension method called Moq.MockExtensions.ResetCalls().

With this method you can do exactly what you wished as shown below:

[Test]
public void Justification()
{
    var foo = new Mock<IFoo>(MockBehavior.Loose);
    foo.Setup(x => x.Fizz());

    var objectUnderTest = new ObjectUnderTest(foo.Object);

    objectUnderTest.DoStuffToPushIntoState1(); // this is various lines of code and setup

    foo.Verify(x => x.Fizz());

    foo.ResetCalls(); // *** Reset the verification here with this glorious method ***

    objectUnderTest.DoStuffToPushIntoState2(); // more lines of code

    foo.Verify(x => x.Fizz(), Times.Never());
}

Update

Now instead of .ResetCalls() we should use .Invocations.Clear() on the latest version of the library:

foo.Invocations.Clear()