Adding Test Categories with xUnit

When writing unit tests it can be helpful to group unit tests using categories. For example, if I have both unit and integration tests in the same solution I can group the unit tests by adding a trait:

using Xunit;

namespace MyNamespace
{
    [Trait("Category", "Unit")]
    public class MyUnitTests
    {
        [Fact]
        public void MyTest()
        {
            ...
        }
    }
}

This is fine for small projects, but if there are numerous test classes in a project it can become cumbersome and easy to miss one or two out.

Assembly-Level Traits

Fortunately it is possible to apply a trait to an entire test project.

At the root of your test project create a folder called Properties.

In that folder, create a file named AssemblyInfo.cs. Copy the following content into the file:

using Xunit;
[assembly: AssemblyTrait("Category", "Unit")]

Now all your tests in that project will have the Unit category.

• C Sharp
• XUnit
• Unit Testing