Test if a class has an attribute?

check that

Attribute.GetCustomAttribute(typeof(ScheduleController),
    typeof(SubControllerActionToViewDataAttribute))

isn't null (Assert.IsNotNull or similar)

(the reason I use this rather than IsDefined is that most times I want to validate some properties of the attribute too....)

The same you would normally check for an attribute on a class.

Here's some sample code.

typeof(ScheduleController)
.IsDefined(typeof(SubControllerActionToViewDataAttribute), false);

I think in many cases testing for the existence of an attribute in a unit test is wrong. As I've not used MVC contrib's sub controller functionality I can't comment whether it is appropriate in this case though.

I know this thread is really old, but if somebody stumble upon on it you may find fluentassertions project very convenient for doing this kind of assertions.

typeof(MyPresentationModel).Should().BeDecoratedWith<SomeAttribute>();

It is also possible to use generics on this:

var type = typeof(SomeType);
var attribute = type.GetCustomAttribute<SomeAttribute>();

This way you do not need another typeof(...), which can make the code cleaner.