neo-tree-preview filetype doesn't work

[KerryCerqueira]

Somewhere in my config I set vim foldmethods to use treesitter expressions which causes buffers to open with folds closed. This makes neotree floating preview windows pretty useless, but according to the :h neo-tree-preview-mode

If you want to work with the floating preview mode window in autocmds or other custom code, the window will have the neo-tree-preview filetype.

However, this autocommand didn't have the intended effect.

vim.api.nvim_create_autocmd("FileType", {
	pattern = "neo-tree-preview",
	callback = function()
		vim.opt_local.foldmethod = "manual"
	end,
})

In fact, set filetype? reports that the filetype of the preview window is not being set by neotree. So, I'm not sure how to solve my problem, or what the documentation means.

[pynappo]

When the preview buffer is created it isn't immediately displayed in the preview window, therefore setting a window local option via filetype will basically do a no-op. what you have to actually do is wait until the buffer gets displayed into a window before setting foldmethod:

vim.api.nvim_create_autocmd('FileType', {
  pattern = 'neo-tree-preview',
  callback = function(args)
    vim.api.nvim_create_autocmd('BufWinEnter', {
      buffer = args.buf,
      once = true,
      callback = function() vim.wo[0].foldmethod = 'manual' end,
    })
  end,
})

I'll see if the documentation can be clearer about this. maybe we should just wait until the window opens to set the filetype but i think usually filetypes are set before being displayed in windows.