CODEWITHSUNDEEP
c#unit-testingattributes
JoshRivers
JoshRivers

Reputation: 10300

Test if a class has an attribute?

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 unit test that the class has that attribute assigned to it?

Upvotes: 144

Views: 102289

Answers (4)

Kroltan
Kroltan

Reputation: 5156

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.

Upvotes: 24

Aleksey L.
Aleksey L.

Reputation: 38046

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>();

Upvotes: 13

RichardOD
RichardOD

Reputation: 29157

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.

Upvotes: 100

Marc Gravell
Marc Gravell

Reputation: 1064324

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....)

Upvotes: 163

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