Error testing Private static function

Question

I'm having trouble getting my method to search for a private static method. My boss wants this to be verified (although I understand that it really doesn’t need to be verified).

Here is the code I'm trying to verify:

 namespace Retail_Utilities.Printables
    {
        public partial class WarrantyDropoffSlip : INotifyPropertyChanged
        {     
            private static string AddBusinessDays(string businessDays)
            {
                if (string.IsNullOrEmpty(businessDays)) return DateTime.Now.ToShortDateString();
                var bDays = int.Parse(businessDays);
                var date = DateTime.Now;
                while (bDays > 0)
                {
                    date = date.AddDays(1);
                    if (date.DayOfWeek != DayOfWeek.Saturday && date.DayOfWeek != DayOfWeek.Sunday)
                        bDays--;
                }
                return date.ToShortDateString();
            }
      }
}

Here is my test code.

namespace RetailUtilitiesUnitTests.Printables_TEST
{
    [TestClass]
    public class WarrantyDropoffSlipTEST
    {
        [TestMethod]
        public void AddBusinessdays_ValidInput()
        {
            PrivateObject po = new PrivateObject(typeof(WarrantyDropoffSlip));
            object[] parameters = {"Sunday"};
            po.Invoke("AddBusinessDays", parameters);
        }
    }
}

Any ideas?

Answer 1

You can use the PrivateType class to access private static methods.

You would use it this way:

var pt = new PrivateType(typeof(WarrantyDropoffSlip));
object[] parameters = {"Sunday"};
pt.InvokeStatic("AddBusinessDays", parameters);