Unity3DEmptyFolderTool.cs

/// <summary>
/// This tool helps to identify and remove empty folders from your Unity 3D project.
///
/// /// Why do I need this:
/// Empty folders are not committed by git but the connected meta files are.
/// So there will be a creation - deletion cycle between between person with and without such a folder.
///
/// /// Usage:
/// The tool adds a new menu Tools->Empty Folder Tool.
/// 1. If you "Toggle Auto Delete", every time you remove or move something in your project
/// it will remove empty folders connected to the specific operation path. It will put the a Debug.Log for each removed folder.
/// 2. "Show Empty Folder" will put a Debug.Log for each empty folder in your project.
/// 3. "Delete Empty Folder" will delete all empty folders in your project and put a Debug.Log for each removed folder.
///
/// /// Acknowledgment:
/// The basecode is partly from http://ideaplusplus.com/emptydirectoriesremover-cs/, https://gist.github.com/liortal53/780075ddb17f9306ae32
/// </summary>

[InitializeOnLoad]
public class EmptyFolderTool : AssetPostprocessor
{
    private static bool autoDelete;
    private const string MENU_NAME = "Tools/Empty Folder Tool/";
    private const string MENU_NAME_AUTO_DELETE = MENU_NAME + "Toggle Auto Delete";
    private const string ASSET_STRING = "Assets";

    /// Called on load thanks to the InitializeOnLoad attribute
    static EmptyFolderTool()
    {
        autoDelete = EditorPrefs.GetBool(MENU_NAME_AUTO_DELETE, false);

        /// Delaying until first editor tick so that the menu
        /// will be populated before setting check state, and
        /// re-apply correct action
        EditorApplication.delayCall += () =>
        {
            PerformAction(autoDelete);
        };
    }

    [MenuItem(MENU_NAME_AUTO_DELETE)]
    private static void ToggleAction()
    {
        /// Toggling action
        PerformAction(!autoDelete);
    }

    public static void PerformAction(bool enabled)
    {
        /// Set checkmark on menu item
        Menu.SetChecked(MENU_NAME_AUTO_DELETE, enabled);
        /// Saving editor state
        EditorPrefs.SetBool(MENU_NAME_AUTO_DELETE, enabled);

        autoDelete = enabled;
    }

    /// <summary>
    /// Remove Folders Automatically if auto delete is active
    /// </summary>
    private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets, string[] movedAssets, string[] movedFromAssetPaths)
    {
        if (autoDelete)
        {
            DeleteEmptyDirectories(deletedAssets);
            DeleteEmptyDirectories(movedFromAssetPaths);
        }
    }

    private static void DeleteEmptyDirectories(string[] paths)
    {
        foreach (string path in paths)
            DeleteUpmostEmptyDirectory(path);
    }

    private static void DeleteUpmostEmptyDirectory(string assetPath)
    {
        try
        {
            string assetDir = Path.GetDirectoryName(assetPath);
            if (assetDir == ASSET_STRING)
                return;
            string absoluteDir = AssetPathToAbsolutePath(assetDir);
            string[] files = Directory.GetFiles(absoluteDir, "*.*", SearchOption.AllDirectories);
            if (files.Length == 0)
            {
                AssetDatabase.DeleteAsset(assetDir);
                Debug.Log("Deleting : " + assetDir);
                DeleteUpmostEmptyDirectory(Path.GetDirectoryName(assetPath));
            }
        }
        catch
        {
        }
    }

    private static string AssetPathToAbsolutePath(string assetPath)
    {
        if (assetPath == ASSET_STRING)
            return Application.dataPath;
        else
            return Path.Combine(Application.dataPath, assetPath.Substring(ASSET_STRING.Length + 1));
    }

    [MenuItem(MENU_NAME + "Show empty folders")]
    private static void ShowEmptyFoldersMenuItem()
    {
        RemoveEmptyFoldersFunc(true);
        Debug.Log("Show empty folders is done.");
    }

    [MenuItem("Tools/Empty Folder Tool/Remove empty folders")]
    private static void RemoveEmptyFoldersMenuItem()
    {
        RemoveEmptyFoldersFunc(false);
        Debug.Log("Remove empty folders is done.");
    }

    private static void RemoveEmptyFoldersFunc(bool dryRun)
    {
        var index = Application.dataPath.IndexOf("/Assets");
        var projectSubfolders = Directory.GetDirectories(Application.dataPath, "*", SearchOption.AllDirectories);

        // Create a list of all the empty subfolders under Assets.
        var emptyFolders = projectSubfolders.Where(path => IsEmptyRecursive(path)).ToArray();

        foreach (var folder in emptyFolders)
        {
            // Verify that the folder exists (may have been already removed).
            if (Directory.Exists(folder))
            {
                if (dryRun)
                {
                    Debug.Log("Found Empty Folder : " + folder);
                }

                if (!dryRun)
                {
                    Debug.Log("Deleting : " + folder);
                    // Remove dir (recursively)
                    Directory.Delete(folder, true);

                    // Sync AssetDatabase with the delete operation.
                    AssetDatabase.DeleteAsset(folder.Substring(index + 1));
                }
            }
        }

        // Refresh the asset database once we're done.
        AssetDatabase.Refresh();
    }

    /// <summary>
    /// A helper method for determining if a folder is empty or not.
    /// </summary>
    private static bool IsEmptyRecursive(string path)
    {
        // A folder is empty if it (and all its subdirs) have no files (ignore .meta files)
        return Directory.GetFiles(path).Select(file => !file.EndsWith(".meta")).Count() == 0
            && Directory.GetDirectories(path, string.Empty, SearchOption.AllDirectories).All(IsEmptyRecursive);
    }
}

Hey. Cool script, thanks.

Having a few issues with it.

Firstly - it's missing imports:

using UnityEngine;
using UnityEditor;
using System.IO;
using System.Linq;

And next issue is that the auto delete doesn't seem to work or stay on. I think I'd like to hook it up so that it deletes empty folder before save project. If I make any changes I'll make sure to fork and comment.

Ah, correction. The auto delete option seems to work but then toggles itself off.