TFS Build activity that can delete long paths such as those created by nested node.js modules.

Readme.txt

Turns out the DeleteDirectory operation in the VB DLLs calls the Win32 APIs which is able to handle long paths:

http://stackoverflow.com/a/3282456/79842

Mind you this exposes you to a whack of Win32 quirks such as file handle / lock timing issues:

http://stackoverflow.com/a/1703799/79842

The above code tries to deal with that.

CleanWorkspace.cs

using System;
using System.Activities;
using System.IO;
using Microsoft.TeamFoundation.Build.Client;
using Microsoft.TeamFoundation.Build.Activities.Extensions;
using Microsoft.TeamFoundation.Build.Workflow.Activities;
using Microsoft.VisualBasic.FileIO;

namespace CleanWorkspaceEx
{
    [BuildActivity(HostEnvironmentOption.Agent)]
    public sealed class CleanWorkspace : CodeActivity
    {
        // Define an activity input argument of type string
        public InArgument<bool> Enabled { get; set; }
        public InArgument<string> WorkingFolder { get; set; }

        // If your activity returns a value, derive from CodeActivity<TResult>
        // and return the value from the Execute method.
        protected override void Execute(CodeActivityContext context)
        {
            if (!Enabled.Get(context)) return;

            var workingFolder = WorkingFolder.Get(context) ??
                                context.GetExtension<IEnvironmentVariableExtension>()
                                    .GetEnvironmentVariable<string>(context,
                                        WellKnownEnvironmentVariables.SourcesDirectory);

            if (!FileSystem.DirectoryExists(workingFolder)) return;
            context.TrackBuildMessage(String.Format("Deleting working folder {0}", workingFolder));
            DeleteDirectory(workingFolder);
        }

        public static void DeleteDirectory(string path)
        {
            foreach (var directory in FileSystem.GetDirectories(path))
            {
                DeleteDirectory(directory);
            }

            try
            {
                FileSystem.DeleteDirectory(path, DeleteDirectoryOption.DeleteAllContents);
            }
            catch (IOException)
            {
                File.SetAttributes(path, FileAttributes.Normal);
                FileSystem.DeleteDirectory(path, DeleteDirectoryOption.DeleteAllContents);
            }
            catch (UnauthorizedAccessException)
            {
                File.SetAttributes(path, FileAttributes.Normal);
                FileSystem.DeleteDirectory(path, DeleteDirectoryOption.DeleteAllContents);
            }
        }
    }
}