A very simple attribute that can be used to record assumptions (if any) for any nunit based tests; after adding this attribute with some assumption text, when the concerned nunit test is run. the assumption text is displayed in the console..

TestAssumptionAttribute.cs

    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = true) ]
    public class TestAssumptionAttribute : TestActionAttribute
    {
        private readonly string assumption;
        public TestAssumptionAttribute(string assumption)
        {
            this.assumption = assumption;
        }
        public override void BeforeTest(TestDetails testDetails)
        {
            Console.WriteLine("This test assumes that : {0}", this.assumption);
            base.BeforeTest(testDetails);
        }
        public override ActionTargets Targets
        {
            get { return ActionTargets.Test | ActionTargets.Suite; }
        }
    }