How do I tell ReSharper that an attribute means that a method is used?

Roger Lipscombe picture Roger Lipscombe · May 20, 2010 · Viewed 7k times · Source

I'm playing with SpecFlow, and ReSharper thinks that my step definitions are unused (I guess because they're used via reflection):

[Binding]
public class StepDefinitions
{
    // ...

    [When(@"I press add")]
    public void WhenIPressAdd()   // R# thinks this is unused
    {
        _calculator.PressAdd();
    }

    // ...
}

How can I tell ReSharper that methods with [Given], [When], [Then] attributes (etc.) are actually used? I don't want to use // ReSharper disable UnusedMember.Global comments.

I could also mark each method (or the whole class) with [JetBrains.Annotations.UsedImplicitly]. I don't particularly want to do that either.

Answer

Ilya Ryzhenkov picture Ilya Ryzhenkov · May 21, 2010

You need to use JetBrains Annotations, and mark the attribute with an MeansImplicitUseAttribute. You can either reference JetBrains.Annotations.dll directly, or you can copy the annotations source code (from ReSharper / Options / Code Inspection / Code Annotations) into your solution.

If you need to annotate some external assembly you don't own, you need to create an External Annotation file (xml) in the following folder: %ReSharperInstallDir%\Bin\ExternalAnnotations. There are plenty of examples, you can just copy some.

The external annotations file can also be in the same path as the DLL if you name it DllNameWithoutExtension.ExternalAnnotations.xml.