BinarySearch in C#

BinarySearchTests.cs

using System;
using System.Linq;
using NUnit.Framework;

namespace Alexw.Katas.BinarySearch
{
    public class BinarySearchTests
    {
        private static readonly DataItem[] Items = 
        {
            new DataItem(1, true),
            new DataItem(2, true),
            new DataItem(3, true),
            new DataItem(4, true),
            new DataItem(5, true),
            new DataItem(6, true),
            new DataItem(7, true),
            new DataItem(8, true),
            new DataItem(9, true),
            new DataItem(10, true),
            new DataItem(11, true),
            new DataItem(12, true),
            new DataItem(13, false)
        };

        [Test]
        public void GivenListOfItems_FindTheFirstElementBroken()
        {
            var result = new BinarySearcher().Find(Items);

            Assert.That(result, Is.EqualTo(11));
        }
    }

    public class BinarySearcher
    {
        private const bool SearchingFor = true;

        public int Find(DataItem[] input)
        {
            var min = 1;
            var max = input.Length;
            var current = max / 2;
            while (true)
            {
                var itemBelow = input.ElementAtOrDefault(current - 1);
                var item = input.ElementAt(current);
                var itemAbove = input.ElementAtOrDefault(current + 1);

                var result = IsMatch(itemBelow, item, itemAbove);
                if (result > 0)
                {
                    // we think it's above us
                    min = current + 1;
                }
                else if (result < 0)
                {
                    // we think it's below us
                    max = current - 1;
                }
                else
                {
                    // this is the item
                    return current;
                }

                current = (min + max) / 2;
            }
        }

        public int IsMatch(DataItem itemBelow, DataItem item, DataItem itemAbove)
        {
            if (itemAbove != null && itemAbove.Value == SearchingFor)
                return 1;
            
            if (item.Value)
                return 0;
            
            return -1;
        }
    }

    public class DataItem
    {
        public int Key { get; }
        public bool Value { get; }

        public DataItem(int key, bool value)
        {
            Key = key;
            Value = value;
        }
    }
}