LessBundle

LessBundle.cs

public class LessBundle : Bundle
{
    public LessBundle(string virtualPath) : base(virtualPath, new LessTransform(), new CssMinify()) { }
}

public class LessTransform : IBundleTransform
{
    public void Process(BundleContext context, BundleResponse response)
    {
        var sb = new StringBuilder();
        foreach(var file in response.Files) {
            var importer = new Importer(new FileReader(new SimplePathResolver(file.Directory.FullName)));
            var parser = new Parser(new PlainStylizer(), importer);
            var engine = new LessEngine(parser, new DiagnosticsLogger(LogLevel.Debug), false, true);
            using (var stream = file.OpenText())
            {
                var less = stream.ReadToEnd();
                var css = engine.TransformToCss(less, null);
                sb.AppendLine(css);
            }
        }
        response.Content = sb.ToString();
        response.ContentType = "text/css";
    }
}

class MappedImporter : Importer
{
    private readonly string _currentDirectory;

    public MappedImporter(string currentDirectory)
    {
        _currentDirectory = currentDirectory;
    }

    protected override string CurrentDirectory { get { return _currentDirectory; } }
}

class SimplePathResolver : IPathResolver
{
    private readonly string _root;

    public SimplePathResolver(string root)
    {
        _root = root;
    }

    public string GetFullPath(string path)
    {
        var output = Path.Combine(_root, path);
        return output;
    }
}