Exception tracker

ExceptionTracker.cs

/// <summary>
/// Tracks exception which was thrown after instantiation of the tracker.
/// </summary>
/// <remarks>
/// It can be used to get the exception in finally block of try-catch-finally.
/// </remarks>
/// <example>
/// <code>
/// var tracker = new ExceptionTracker();
/// try
/// {
/// 	throw new InvalidOperationException();
/// }
/// finally
/// {
/// 	Console.WriteLine(tracker.BubblingUpException);
/// }
/// </code>
/// </example>
public readonly struct ExceptionTracker
{
	[ThreadStatic]
	private static WeakReference _currentException;

	static ExceptionTracker()
	{
		AppDomain.CurrentDomain.FirstChanceException += (s, e) =>
		{
			_currentException = new WeakReference(e.Exception, trackResurrection: false);
		};
	}

	private readonly IntPtr _exceptionAddress;

	public ExceptionTracker()
	{
		_exceptionAddress = Marshal.GetExceptionPointers();
	}

	/// <summary>
	/// Indicates exception was thrown after the tracker was instantiated.
	/// If there's no exception or it was already propagating trough the stack,
	/// this property will return <c>false</c>.
	/// </summary>
	private readonly bool IsExceptionBubblingUp
	{
		get
		{
			var curentExceptionAddr = Marshal.GetExceptionPointers();
			var isExceptionBubblingUp = _exceptionAddress != curentExceptionAddr && curentExceptionAddr != IntPtr.Zero;

			return isExceptionBubblingUp;
		}
	}

	public readonly Exception? BubblingUpException
		=>
		IsExceptionBubblingUp && _currentException.Target is Exception ex
		? ex
		: null;
}