Check if the class has an attribute?

Question

I'm trying to do a little Test-First development, and I'm trying to verify that my classes are marked with an attribute:

[SubControllerActionToViewDataAttribute] public class ScheduleController : Controller 

How do I assign a unit test to this class class?

Answer 1

check that

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

non-null ( Assert.IsNotNull or similar)

(the reason I use this, rather than IsDefined , is because in most cases I want to check some attribute properties as well ....)

Answer 2

You usually check the same for an attribute in a class.

Here is a sample code.

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

I think in many cases, testing for an attribute in a unit test is incorrect. Since I did not use the functions of the MVC contrib subcontroller, I cannot comment on whether this is appropriate in this case.

Answer 3

You can also use generics:

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

This way you don't need another typeof(...) that can make the code cleaner.

Answer 4

I know that this branch is really old, but if someone stumbles upon it, you can find a fluentassertions project that is very convenient for such statements.

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