Code to find project root path in a visual studio project

ProjectSourcePath.cs

using System.Runtime.CompilerServices;
// Ripped from S.O. answer: https://stackoverflow.com/a/66285728/1594171
// 1. Put this code in ProjectSourcePath.cs at root of project
// 2. Reference project path like this: ProjectSourcePath.Value
internal static class ProjectSourcePath
{
    private const string myRelativePath = nameof(ProjectSourcePath) + ".cs";
    private static string? lazyValue;
    public static string Value => lazyValue ??= CalculatePath();

    private static string CalculatePath()
    {
        string pathName = GetSourceFilePathName();
        return pathName.Substring(0, pathName.Length - myRelativePath.Length);
    }

    public static string GetSourceFilePathName([CallerFilePath] string? callerFilePath = null) => 
        callerFilePath ?? "";
}

https://stackoverflow.com/a/66285728/1594171