Grader service tests

GraderService.Tests.cs

using NUnit.Framework;
using Grader.Service;

namespace Tests
{
    public class Tests
    {
        private GradeConverter gc = new GradeConverter();

        [TestCase(90)]
        [TestCase(91)]
        [TestCase(95)]
        [TestCase(100)]
        [TestCase(101)]
        public void ShouldGetA(int value)
        {
            Assert.AreEqual('A', gc.GetLetterGrade(value));
        }

        [TestCase(80)]
        [TestCase(81)]
        [TestCase(89)]
        public void ShouldGetB(int value)
        {
            Assert.AreEqual('B', gc.GetLetterGrade(value));
        }


    }
}