The very last Configuration Section Handler I hope I'll ever need

using System;
using System.IO;
using System.Reflection;

using Haack.Example;
using NUnit.Framework;

namespace UnitTests.Haack.Configuration
{
	/// <summary>
	/// Performs a quick test showing that the settings object 
	/// does indeed track changes to the config file.
	/// </summary>
	[TestFixture]
	public class ConfigurationTests
	{
		/// <summary>
		/// Grabs an instance of MyStuff, overwrites the config file, then 
		/// makes sure the instance has its settings updated.
		/// </summary>
		[Test]
		public void TestTrackChanges()
		{
			//Grab the settings object. 
			// Could have used the static MyStuff.Settings property as well.
			MyStuff settings = (MyStuff)System.Configuration.ConfigurationSettings.GetConfig("MyStuff");

			//Assert the original values
			Assertion.AssertEquals("A bunch of information", settings.Bar);
			Assertion.AssertEquals(1.234, settings.Foo);
			
			//Ok, we're ready to make a change to the config file.
			WriteConfigFile("UnitTests.Haack.Configuration.NewApp.config");

			//Let's give a small bit of time for the change to propagate.
			System.Threading.Thread.Sleep(200); //plenty of time.

			//Moment of truth. Did the settings object get updated 
			//with the new values???  The public wants to know!
			//Note the same instance of settings.
			Assertion.AssertEquals("Nothing useful here.", settings.Bar);
			Assertion.AssertEquals(2.718281, settings.Foo);	
		}

		/// <summary>
		/// Writes the embedded App.config file into the appropriate directory.
		/// </summary>
		[SetUp]
		private void SetUp()
		{
			WriteConfigFile("UnitTests.Haack.Configuration.App.config");
		}

		// Overwrites the config file with the file embedded in the unit test assembly.
		void WriteConfigFile(string resourceName)
		{
			Assembly assembly = Assembly.GetExecutingAssembly();
			using(Stream resourceStream = assembly.GetManifestResourceStream(resourceName))
			{
				using(StreamReader reader = new StreamReader(resourceStream))
				{
					using(StreamWriter writer = new StreamWriter(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile))
					{
						writer.Write(reader.ReadToEnd());
						writer.Flush();
					}
				}
			}
		}

		/// <summary>
		/// Deletes the config file.
		/// </summary>
		[TearDown]
		private void TearDown()
		{
			try
			{
				File.Delete(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile);
			}
			catch(Exception e)
			{
				Console.WriteLine("Something bad happened." + e.Message);
			}
		}
	}
}