SurrogatePairDetection.cs

using System.Collections.Generic;
using System.Linq;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace SurrogatePairDetection
{
	[TestClass]
	public class SurrogatePairDetection
	{
		[TestMethod]
		public void LengthTest()
		{
			var s = "𠮷hal𠮷lo野";
			var symbols = Symbols(s).ToList();
			Assert.AreEqual(8, symbols.Count());
		}

		[TestMethod]
		public void SymbolsTest()
		{
			var s = "𠮷hal𠮷lo野";
			var symbols = Symbols(s).ToList();
			CollectionAssert.AreEqual(new List<string> { "𠮷", "h", "a", "l", "𠮷", "l", "o", "野" }, symbols);
		}

		private IEnumerable<string> Symbols(string s)
		{
			for (int i = 0; i < s.Length; i++)
			{
				if (i + 1 < s.Length && char.IsSurrogatePair(s[i], s[i + 1]))
				{
					yield return new string(new[] { s[i], s[i + 1] });
					i++;
				}
				else
				{
					yield return s[i].ToString();
				}
			}
		}
	}
}