Can I test method call order with AAA syntax in Rhino-Mocks 3.6?

Question

Is it possible to test for the following example if the Method1 called 1st, then Method2 called after and then Method3 by using the AAA syntax, in Rhino-mocks 3.6 ?

Answer 1

Here's how to do it by building assertions into each method invocation.

// Arrange - Build the necessary assertions into the stubbed method invocations.
var mock = MockRepository.GenerateMock();
mock.Stub(m => m.Method1()).WhenCalled(inv => mock.AssertWasNotCalled(m => m.Method2()));
mock.Stub(m => m.Method2()).WhenCalled(inv => mock.AssertWasNotCalled(m => m.Method3()));

// Act
myObject.Service = mock;

// Assert - Ensure each expected method was called.
mock.AssertWasCalled(m => m.Method1());
mock.AssertWasCalled(m => m.Method2());
mock.AssertWasCalled(m => m.Method3());

Since this is mixes up normal arrange-act-assert pattern by running assertions in mid-act, I like to include very specific error messages for these instances to identify test failures more easily.

mock.Stub(m => m.Method1()).WhenCalled(inv =>
    mock.AssertWasNotCalled(m => m.Method2(), opt =>
        opt.Message("Method2 cannot be called before Method1.")));

You could also achieve a similar result by saving the result of each invocation in a variable during the act step, and then checking the variable states during the assert step. This better preserves the division of the arrange-act-assert pattern, but it is more plumbing code to write and maintain.

// Arrange - Build the necessary state variables into the stubbed method invocations.
bool wasMethod1Called;
bool wasMethod2Called;
bool wasMethod2CalledBeforeMethod1;
bool wasMethod3CalledBeforeMethod2;

var mock = MockRepository.GenerateMock();
mock.Stub(m => m.Method1()).WhenCalled(inv =>
{
    wasMethod1Called = true;
});
mock.Stub(m => m.Method2()).WhenCalled(inv =>
{
    wasMethod2Called = true;
    wasMethod2CalledBeforeMethod1 = !wasMethod1Called;
});
mock.Stub(m => m.Method3()).WhenCalled(inv =>
{
    wasMethod3CalledBeforeMethod2 = !wasMethod2Called;
});

// Act
myObject.Service = mock;

// Assert - Ensure each expected method was called, and that they were called in the right order.
mock.AssertWasCalled(m => m.Method1());
mock.AssertWasCalled(m => m.Method2());
mock.AssertWasCalled(m => m.Method3());
Assert.That(wasMethod2CalledBeforeMethod1, Is.False, "Method2 cannot be called before Method1.");
Assert.That(wasMethod3CalledBeforeMethod2, Is.False, "Method3 cannot be called before Method2.");