Git won't tracked directory changes so you need remove them yourself after checkout. Unity would generate .meta file for every file and directory. So these hooks use to remove empty directory and its .meta file for consistency.

• Git for Windows
• Git on macOS

Just copy install-hooks.sh and hooks directory to your git repository, then run install-hooks.sh.

• file mode

  hooks/post-checkout and hooks/post-merge don't set executable attribute but set when run install-hooks.sh. It's because of Git for Windows. Git for Windows doesn't set core.filemode to true. So every file is always 644.

• depth first

  When find empty directories, we need find to perform depth-first traversal. And we need delete every empty directory when encountered. So that we could remove nested empty directories.

• useless files

  There are too many useless files exist in working dir, include .DS_Store, Thumbs.db, Desktop.ini, desktop.ini. They are generated occasionally by Operating System. These files are usually ignored in .gitignore file. Then Git treat containing directory didn't exist but Unity don't think so. Unity would generate corresponding .meta for directory. We need delete these useless ignored files.

You could run hooks/testcase.sh to build test directory structure. And then you could run hooks/post-checkout.sh or hooks/post-merge to remove empty directories.

• 3pjgames/unity-git-hooks: Git hooks for Unity3D project