How do I use MoqSequence

Question

I want to test the order of execution of the methods of three dependencies within a class. That is, check to ensure a method is called on class a, then b and then c and are executed and in that order.

I was going to use the Moq.Sequence library but I have found that sequence testing is now supported out of the box. The only thing is that documentation is very light on the ground about the MoqSequence class, and I cant find a concrete example.

Also, my question is not about whether this is right or wrong specifically, but I believe testing the order of execution is a valid test (bit of a grey area here?)

Answer 1

There is bug when using MockSequence on same mock. It definitely will be fixed in later releases of Moq library (you can also fix it manually by changing Moq.MethodCall.Matches implementation).

If you want to use Moq only, then you can verify method call order via callbacks:

int callOrder = 0;
writerMock.Setup(x => x.Write(expectedType)).Callback(() => Assert.That(callOrder++, Is.EqualTo(0))); 
writerMock.Setup(x => x.Write(expectedId)).Callback(() => Assert.That(callOrder++, Is.EqualTo(1))); 
writerMock.Setup(x => x.Write(expectedSender)).Callback(() => Assert.That(callOrder++, Is.EqualTo(2)));