undotree

Add the following line to your configuration file depending on your plugin manager, then run the corresponding install command:

• Vundle: Plugin 'mbbill/undotree' (Run :PluginInstall)
• Vim-Plug: Plug 'mbbill/undotree' (Run :PlugInstall)
• Packer: use 'mbbill/undotree' (Run :PackerSync)

To install undotree manually using Vim's native package system, run the following commands in your terminal:

mkdir -p ~/.vim/pack/mbbill/start
cd ~/.vim/pack/mbbill/start
git clone https://github.com/mbbill/undotree.git
vim -u NONE -c "helptags undotree/doc" -c q

By default, Vim's undo history is lost when the session ends. To persist undo history across sessions, you can configure a dedicated directory in your .vimrc:

if has("persistent_undo")
   let target_path = expand('~/.undodir')

    " create the directory and any parent directories
    if !isdirectory(target_path)
        call mkdir(target_path, "p", 0700)
    endif

    let &undodir=target_path
    set undofile
endif

Alternatively, you can persist the undo history for only the currently open file by running the command :UndotreePersistUndo.

To enable debugging, create a file named undotree_debug.log in your home directory. The plugin will automatically append logs to this file. You can monitor the logs in real-time using tail:

touch ~/undotree_debug.log
tail -F ~/undotree_debug.log

To disable debugging, simply delete the ~/undotree_debug.log file.

The undotree window uses specific markers to indicate the state of the undo history:

• > number <: The current state.
• { number }: The next state that will be restored by :redo or <ctrl-r>.
• [ number ]: The most recent change.
• s: Saved changes.
• S: The most recent saved change.
• Every change includes a sequence number displayed before the timestamp.

Use the :UndotreeToggle command to open or close the undo-tree visualization panel.

To map this to a key in your .vimrc (e.g., F5):

noremap <F5> :UndotreeToggle<CR>

To map this in Neovim using Lua:

vim.keymap.set('n', '<leader><F5>', vim.cmd.UndotreeToggle)