C# WaitForExitAsync implementation

ProcessExtensions.cs

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

namespace Daniel15.Extensions
{
	/// <summary>
	/// Extensions for <see cref="Process"/>
	/// </summary>
	public static class ProcessExtensions
	{
		/// <summary>
		/// Asynchronously waits for the process to exit.
		/// </summary>
		public static async Task<int> WaitForExitAsync(this Process process, CancellationToken cancellationToken = default)
		{
			var tcs = new TaskCompletionSource<int>();
			void ExitHandler(object sender, EventArgs e) => tcs.TrySetResult(process.ExitCode);

			int exitCode;
			try
			{
				process.EnableRaisingEvents = true;
				process.Exited += ExitHandler;
				if (process.HasExited)
				{
					tcs.TrySetResult(process.ExitCode);
				}

				await using (cancellationToken.Register(() => tcs.TrySetCanceled()))
				{
					exitCode = await tcs.Task.ConfigureAwait(false);
				}
			}
			finally
			{
				process.Exited -= ExitHandler;
			}

			return exitCode;
		}
	}
}