Undo History Refined

astrolsp_no_undo.lua

-- Disable undo history for LSP formatting/code actions
-- This prevents import organization and formatting from cluttering undo history

---@type LazySpec
return {
  "AstroNvim/astrolsp",
  opts = {
    autocmds = {
      format_on_save_preserve_undo = {
        {
          event = "BufWritePre",
          desc = "Preserve undo history during LSP formatting",
          callback = function(args)
            -- Only proceed if format on save is enabled
            local astrolsp = require "astrolsp"
            if not astrolsp.config.formatting.format_on_save.enabled then return end

            -- Get the current buffer's filetype
            local ft = vim.bo[args.buf].filetype

            -- Check if we should preserve undo for this filetype
            local affected_filetypes = {
              typescript = true,
              typescriptreact = true,
              javascript = true,
              javascriptreact = true,
            }

            if affected_filetypes[ft] then
              -- Save the current undo tree to a temporary file
              local tmpfile = vim.fn.tempname()
              vim.cmd("wundo! " .. tmpfile)

              -- Store the temp file path in buffer variable for restoration
              vim.b[args.buf].undo_tmpfile = tmpfile

              -- Clear undo history
              local undolevels = vim.o.undolevels
              vim.o.undolevels = -1
              vim.o.undolevels = undolevels
            end
          end,
        },
        {
          event = "BufWritePost",
          desc = "Restore undo history after LSP formatting",
          callback = function(args)
            -- Check if we saved undo history for this buffer
            if vim.b[args.buf].undo_tmpfile then
              local tmpfile = vim.b[args.buf].undo_tmpfile

              -- Restore the undo tree from the temporary file
              if vim.fn.filereadable(tmpfile) == 1 then
                vim.cmd("silent! rundo " .. tmpfile)
                -- Clean up the temp file
                vim.fn.delete(tmpfile)
              end

              -- Clear the buffer variable
              vim.b[args.buf].undo_tmpfile = nil
            end
          end,
        },
      },
    },
  },
}