Can I assert that a C# method has a certain attribute?-CodePudding

[DummyAttribute]
public void DummyMethod() {
  return;
}

I want to write a Nunit test that will assert that DummyMethod is decorated with DummyAttribute, can I do that ?

CodePudding user response：

Yes, with reflection. One possible solution:

var dummyAttribute = typeof(YourClassName)
    .GetMethod(nameof(YourClassName.DummyMethod))!
    .GetCustomAttributes(inherit: false)
    .OfType<DummyAttribute>()
    .SingleOrDefault();

Assert.That(dummyAttribute, Is.Not.Null);

CodePudding user response：

These kinds of tests are often useful to define the functional specification of the codebase.

@kardo's code is absolutely fine and seems it solved your problem as well.

However, if anyone looks for more descriptive unit tests later to specify the functional specs, then I would suggest giving a try on fluent assertions.

typeof(YourClassName).GetMethod(nameof(YourClassName.DummyMethod)).Should().BeDecoratedWith<DummyAttribute>();

CodePudding user response：

Yes, you can reflect or use "fluent assertions" package.

Alternatively, since you're using NUnit already...

Assert.That(typeof(YourClassName).GetMethod(nameof(SomeMethod)),
    Has.Attribute(typeof(DummyAttribute)));