JSON asserting

Json.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web.Script.Serialization;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace Test
{
  static class Json
	{
		public static void CompareJson(string expected, string actual)
		{
			var serializer = new JavaScriptSerializer();
			object expectedValue = serializer.DeserializeObject(expected);
			object actualValue = serializer.DeserializeObject(actual);
			CompareValue(expectedValue, actualValue);
		}

		static void CompareValue(object expected, object actual)
		{
			if (expected is Dictionary<string, object> && actual is Dictionary<string, object>)
			{
				CompareObject(expected as Dictionary<string, object>, actual as Dictionary<string, object>);
			}
			else if (expected is object[] && actual is object[])
			{
				CompareArray(expected as object[], actual as object[]);
			}
			else
			{
				Assert.AreEqual(expected, actual);
			}
		}

		static void CompareObject(Dictionary<string, object> expected, Dictionary<string, object> actual)
		{
			foreach (string key in expected.Keys.Union(actual.Keys))
			{
				if (!actual.ContainsKey(key))
				{
					Assert.Fail("Missing property '{0}' in JSON.", key);
				}
				if (!expected.ContainsKey(key))
				{
					Assert.Fail("Unexpected property '{0}' in JSON.", key);
				}
				CompareValue(expected[key], actual[key]);
			}
		}

		static void CompareArray(object[] expected, object[] actual)
		{
			Assert.AreEqual(expected.Length, actual.Length);
			for (int i = 0; i < expected.Length; i++)
			{
				CompareValue(expected[i], actual[i]);
			}
		}
	}
}