How to follow curr file's project root dir?

[qiine]

The idea is to find the project's root dir based on current file, when entering a buffer and set neotree's root accordingly IF neotree is already open.
But it seems more complicated than I thought.

I have tried this:

     vim.api.nvim_create_autocmd('BufEnter', {
                callback = function()
                local fp =  vim.api.nvim_buf_get_name(0)
                local rootdir = vim.fs.root(fp, {'README.md', "Makefile", ".git"})

                require("neo-tree.command").execute({
                    reveal = false,
                    focus = false,
                    dir = rootdir
                })
            end,
        })

But it does not work properly because it constantly open and try re-focus neotree, which puzzle me..

[qiine]

In fact I realize that I do not know how to set neotree's root dir without opening it in lua.

[pynappo]

For the focusing issue you can add action = "show"

To only do it when neo-tree is open, the current way is basically to loop over open windows and check for vim.bo[bufnr].filetype = "neo-tree"

  local neo_tree_open = function()
    local wins = vim.api.nvim_tabpage_list_wins()
    for i, win in ipairs(wins) do
      local buf = vim.api.nvim_win_get_buf(win)
      if vim.bo[buf].filetype == "neo-tree" then
        return true
      end
    end
    return false
  end
  vim.api.nvim_create_autocmd("BufEnter", {
    callback = function()
      if not neo_tree_open() then
        return
      end
      local fp = vim.api.nvim_buf_get_name(0)
      local rootdir = vim.fs.root(fp, { "README.md", "Makefile", ".git" })

      require("neo-tree.command").execute({
        reveal = false,
        focus = false,
        action = "show",
        dir = rootdir,
      })
    end,
  })