local function open_nvim_tree(data)

  -- buffer is a real file on the disk
  local real_file = vim.fn.filereadable(data.file) == 1

  -- buffer is a [No Name]
  local no_name = data.file == "" and vim.bo[data.buf].buftype == ""

  if not real_file and not no_name then
    return
  end

  -- open the tree, find the file but don't focus it
  require("nvim-tree.api").tree.toggle({ focus = false, find_file = true, })
end

-- Auto open
-- vim.api.nvim_create_autocmd({ "VimEnter" }, { callback = open_nvim_tree })

-- Auto close
vim.api.nvim_create_autocmd({"QuitPre"}, {
    callback = function() vim.cmd("NvimTreeClose") end,
})

-- Go to last used hidden buffer when deleting a buffer
vim.api.nvim_create_autocmd("BufEnter", {
  nested = true,
  callback = function()
    -- Only 1 window with nvim-tree left: we probably closed a file buffer
    if #vim.api.nvim_list_wins() == 1 and require("nvim-tree.utils").is_nvim_tree_buf() then
      local api = require('nvim-tree.api')
      -- Required to let the close event complete. An error is thrown without this.
      vim.defer_fn(function()
        -- close nvim-tree: will go to the last hidden buffer used before closing
        api.tree.toggle({find_file = true, focus = true})
        -- re-open nivm-tree
        api.tree.toggle({find_file = true, focus = true})
        -- nvim-tree is still the active window. Go to the previous window.
        vim.cmd("wincmd p")
      end, 0)
    end
  end
})