Skip testmethods in custom fxcop rule

Question

I am writing a custom fxcop rule which checks for Unused locals. (Yes, there is an existing one, but I want to exclude TestMethods from being checked.)

Where Introspector shows me that the TestMethodAttribute is available at compiletime:

I can not seem to be able to actually check if the Attribute exists.

I tried the following methods:

Method 1.

_TestAttribType = FrameworkAssemblies.Mscorlib.GetType(Identifier.For("Microsoft.VisualStudio.TestTools.UnitTesting"), Identifier.For("TestMethodAttribute"));
AttributeNode testAttribute = method.GetAttribute(_TestAttribType);
if (testAttribute != null)
    return null;

Method 2.

if(method.Attributes.Any(attrib => attrib.ToString().Contains("Test")))
    return null;

Method 3.

if(method.Attributes.Any(attrib => attrib.Type == typeof(TestMethodAttribute))
    return null;

Method 1 would not work because Microsoft.VisualStudio.TestTools.Unittesting is not in mscorlib. The second method didn't work either, I am not sure why. Third method does not compile, because TestMethodAttribute is not supported by the FxCop-API.

How can I exclude testmethods from being checked in my FxCop-rule?

Answer 1

A simple approach based on the name only would be:

method.Attributes.Any(a => a.Type.Name.Name == "TestMethodAttribute")

If you want a more complete solution with some performance enhancements, take a look at the implementation of the IsVSUnitTestMethod method in the MarkMembersAsStatic rule in a decompiler.