namespace Nancy.Testing

{

using System;

using System.IO;

using System.Linq;

public static class PathHelper

{

/// <summary>

/// Traverses up a directory tree

/// </summary>

/// <param name="path">Start path.</param>

/// <param name="levels">Levels to climb.</param>

/// <returns>A <see cref="string"/> containing the new path.</returns>

public static string GetParent(string path, int levels)

{

if (string.IsNullOrEmpty(path))

{

throw new ArgumentException("path cannot be null or empty", "path");

}

if (levels < 0)

{

throw new ArgumentException("levels cannot be negative", "levels");

}

if (levels == 0)

{

return path;

}

var parts = path.Split(Path.DirectorySeparatorChar);

if (parts.Length <= levels)

{

throw new InvalidOperationException("Cannot go up beyond the root.");

}

return

parts.Take(parts.Length - levels).Aggregate(

(p1, p2) => String.Format("{0}{1}{2}", p1, Path.DirectorySeparatorChar, p2));

}

}

}