terminal :enew buffer should set buftype=terminal before BufWinEnter autocmd

[stringTrimmer]

Problem

I have some code I'd like to run when most buffers enter a window, so I create an autocmd for BufWinEnter. But there are some buffers on which I do not want to run this code. I can exclude most of these cases by checking the filetype or buftype. One case that I'd like to exclude is terminal buffers. However when a terminal buffer is created via :terminal and my BufWinEnter autocmd is executed the first time, the buftype is still empty. I've also checked other terminal buffer related variables: b:term_title, the channel local option and getwininfo(buf).[1].terminal, but these are also empty during the initial BufWinEnter. Note: they are present in subsequent BufWinEnters.

This might be fine if I wanted to avoid this code running for any buffer that has empty buftype, filetype, event.file, event.match (as terminal buffers do during initial BufWinEnter), but I do want this code to run on normal new buffers like with :enew (which have the same state).

My current hack is to run the code with vim.defer_fn() after x ms, after which buftype has usually then been set to 'terminal'.

Steps to reproduce:

1. Write the below code to a file 'test.lua'
2. nvim --clean test.lua
3. :source %
4. check the messages to see if buftype et al. have values initially and after the delay.

vim.api.nvim_create_autocmd({ 'BufWinEnter' }, {
  group = vim.api.nvim_create_augroup('DetectTerminalBufWin', { clear = true }),
  desc = 'Find a way to detect if this bufer is (or is going to be) a terminal buffer',
  pattern = '*',
  callback = function(evt)
    vim.print(
      evt.event,
      ('filetype:%s'):format(vim.bo[evt.buf].filetype),
      ('buftype:%s'):format(vim.bo[evt.buf].buftype),
      ('b:term_title:%s'):format(vim.b.term_title),
      ('channel:%s'):format(vim.bo.channel),
      ('getwininfo.terminal:%s'):format(vim.fn.getwininfo(vim.api.nvim_get_current_win())[1].terminal)
    )

    if evt.file == '' and evt.match == '' and vim.bo[evt.buf].filetype == '' and vim.bo[evt.buf].buftype == '' then
      vim.defer_fn(
        function()
          vim.print(
            ' ',
            'defered',
            ('filetype:%s'):format(vim.bo[evt.buf].filetype),
            ('buftype:%s'):format(vim.bo[evt.buf].buftype),
            ('b:term_title:%s'):format(vim.b.term_title),
            ('channel:%s'):format(vim.bo.channel),
            ('getwininfo.terminal:%s'):format(vim.fn.getwininfo(vim.api.nvim_get_current_win())[1].terminal)
          )
        end,
        200
      )
    end
  end,
})
vim.cmd.terminal()

System: Windows 11
nvim: v0.11.0

Expected behavior

Either buftype is set to 'terminal' prior to initial BufWinEnter autocmds or there is some other variable/mechanism to detect a terminal buffer at this time.

[justinmk]

when a terminal buffer is created via :terminal and my BufWinEnter autocmd is executed the first time, the buftype is still empty. I've also checked other terminal buffer related variables: b:term_title, the channel local option and getwininfo(buf).[1].terminal, but these are also empty during the initial BufWinEnter

Surely the name is set? Terminal buffer name always starts with term:// (though it can be renamed later).

[zeertzjq]

BufWinEnter is triggered by the :enew, not the termopen().