FakeItEasy not verifying call for Full Framework SignalR test

Question

I have a simple hub that I am trying to write a test for with FakeItEasy and the verification of calling the client is not passing. I have the example working in a separate project that uses MOQ and XUnit.

public interface IScheduleHubClientContract
{
    void UpdateToCheckedIn(string id);
}

public void UpdateToCheckedIn_Should_Broadcast_Id()
{
    var hub = new ScheduleHub();
    var clients = A.Fake<IHubCallerConnectionContext<dynamic>>();
    var all = A.Fake<IScheduleHubClientContract>();

    var id= "123456789";
    hub.Clients = clients;

    A.CallTo(() => all.UpdateToCheckedIn(A<string>.Ignored)).MustHaveHappened();
    A.CallTo(() => clients.All).Returns(all);

    hub.UpdateToCheckedIn(id);
}

I'm using Fixie as the Unit Test Framework and it reports:

FakeItEasy.ExpectationException:

Expected to find it once or more but no calls were made to the fake object.

The sample below works in XUnit & MOQ:

    public interface IScheduleClientContract
    {
        void UpdateToCheckedIn(string id);

    }

    [Fact]
    public void UpdateToCheckedIn_Should_Broadcast_Id()
    {
        var hub = new ScheduleHub();
        var clients = new Mock<IHubCallerConnectionContext<dynamic>>();
        var all = new Mock<IScheduleClientContract>();
        hub.Clients = clients.Object;
        all.Setup(m=>m.UpdateToCheckedIn(It.IsAny<string>())).Verifiable();
        clients.Setup(m => m.All).Returns(all.Object);

        hub.UpdateToCheckedIn("id");

        all.VerifyAll();

    }

I'm not sure what I've missed in the conversion?

Answer 1

You're doing some steps in a weird (it looks to me, without seeing the innards of your classes) order, and I believe that's the problem.

I think your key problem is that you're attempting to verify that all.UpdateToCheckedIn must have happened before even calling hub.UpdateToCheckedIn. (I don't know for sure that hub.UpdateToCheckedIn calls all.UpdateToCheckedIn, but it sounds reasonable.

There's another problem, where you configure clients.Setup to return all.Object, which happens after you assert the call to all.UpdateToCheckedIn. I'm not sure whether that's necessary or not, but thought I'd mention it.

The usual ordering is

1. arrange the fakes (and whatever else you need)
2. act, but exercising the system under test (hub)
3. assert that expected actions were taken on the fakes (or whatever other conditions you deem necessary for success)

I would have expected to see something more like

// Arrange the fakes
var all = A.Fake<IScheduleHubClientContract>();
var clients = A.Fake<IHubCallerConnectionContext<dynamic>>();
A.CallTo(() => clients.All).Returns(all); // if All has a getter, this could be clients.All = all

// … and arrange the system under test
var hub = new ScheduleHub();
hub.Clients = clients;

// Act, by exercising the system under test
var id = "123456789";
hub.UpdateToCheckedIn(id);

// Assert - verify that the expected calls were made to the Fakes
A.CallTo(() => all.UpdateToCheckedIn(A<string>.Ignored)).MustHaveHappened();