aspnetcore/test/Microsoft.AspNetCore.WebSockets.ConformanceTest/Helpers.cs

using System;
using System.IO;

namespace Microsoft.AspNetCore.WebSockets.ConformanceTest
{
    public class Helpers
    {
        public static string GetApplicationPath(string projectName)
        {
            var applicationBasePath = AppContext.BaseDirectory;

            var directoryInfo = new DirectoryInfo(applicationBasePath);
            do
            {
                var solutionFileInfo = new FileInfo(Path.Combine(directoryInfo.FullName, "WebSockets.sln"));
                if (solutionFileInfo.Exists)
                {
                    return Path.GetFullPath(Path.Combine(directoryInfo.FullName, "test", projectName));
                }

                directoryInfo = directoryInfo.Parent;
            }
            while (directoryInfo.Parent != null);

            throw new Exception($"Solution root could not be found using {applicationBasePath}");
        }
    }
}