bug: highlighting doesn't work with nvim-treesitter main branch

[iguanacucumber]

Describe the bug

• On the treesitter main branch (rewrite of treesitter, and now the default branch):
  when opening a markdown with a codeblock inside, it displays this warning:

[otter] No treesitter parser found for current buffer. Can't activate.
Code highlighting doesn't happen

• On the treesitter master branch:
  It just works

To Reproduce
Use those init.lua and open a markdown file with a lua codeblock inside:

• Treesitter master branch

vim.env.LAZY_STDPATH = ".repro-master"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro({
	spec = {
		{
			"nvim-treesitter/nvim-treesitter",
			build = ":TSUpdate",
      lazy = false,
			branch = "master",
			config = function()
				require("nvim-treesitter.configs").setup({
					ensure_installed = { "c", "lua", "vim", "vimdoc", "query", "markdown", "markdown_inline" },
          auto_install = true,
          highlight = { enable = true }
				})
			end,
		},

		{
			"jmbuhr/otter.nvim",
			dependencies = "nvim-treesitter/nvim-treesitter",
			config = function()
				require("otter").activate({ "lua" }, false, false, nil)
			end,
		},
	},
})

• Treesitter main branch

vim.env.LAZY_STDPATH = ".repro-main"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro({
	spec = {
		{
			"nvim-treesitter/nvim-treesitter",
			build = ":TSUpdate",
      lazy = false,
			branch = "main",
			config = function()
				require("nvim-treesitter").setup()
				require("nvim-treesitter").install({
          "c", "lua", "vim", "vimdoc", "query", "markdown", "markdown_inline"
				})
			end,
		},

		{
			"jmbuhr/otter.nvim",
			dependencies = "nvim-treesitter/nvim-treesitter",
			config = function()
				require("otter").activate({ "lua" }, false, false, nil)
			end,
		},
	},
})

System

• OS: Arch linux
• Nvim version: Stable and nightly
• otter.nvim version: c44d645

[jmbuhr]

Thanks for the detailed reprex! Just to clarify, otter doesn't do any highlighting, that is just from treesitter/neovim itself. What we do is look for the injections and add LSP features for those.

But what otter requires is for treesitter to be active for the buffer for which it is being activated. The new treesitter seems to require explicit activation: https://github.com/nvim-treesitter/nvim-treesitter/tree/main?tab=readme-ov-file#highlighting.
I haven't tested it myself, but I don't see this in your reprex, do you get treesitter highlighting anywhere?

Also, it looks like you are activating otter directly in the config function, which is usually meant for setup and options. I suspect by doing that you are attempting to activate otter while not even in a buffer yet and while treesitter is also not set up. Try putting the activate call in an autocommand or e.g. at the bottom of an ftplugin/markdown.lua file.

[SandyJackson]

I've come across this issue. Think I have worked out at least part of the issue. My TS Main setup sets up treesitter on a per file basis with an autocommand like this (based off MiniMax and LazyVim):

      vim.api.nvim_create_autocmd("FileType", {
        group = vim.api.nvim_create_augroup("treesitter-setup", { clear = true }),
        pattern = filetypes,
        callback = function(event)
          local lang = vim.treesitter.language.get_lang(event.match)
          end
          vim.treesitter.start(event.buf, lang)
-- Callback continues here...

Now when it wasn't working I did print(vim.inspect(event)) and found a table that looks like this:

{
  buf = 4,
  event = "FileType",
  file = "/Your/File/Path/yourfile.qmd.otter.yml",
  group = 19,
  id = 56,
  match = "yaml"
}

So this means the autocommand ONLY triggers with YAML and its the only TS parser started. So the markdown seems to fallback to pandoc regex highlighting with some undesirable behaviours.

The workaround (for now) seems to be using ~/.config/nvim/after/ftplugin/quarto.lua and putting vim.treesitter.start(0,"markdown"). I still seem to get codeblock and frontmatter highlighting (presumably via otter).

I think it's just that the way otter works confuses with the FileType autocommand event. Took me a good few hours to figure that one out! (The regex highlighting was awful).

TL;DR: You can get Treesitter main to work in quarto with otter using a file at ~/.config/nvim/after/ftplugin/quarto.lua with a single line that says vim.treesitter.start(0, "markdown")

Edit: Just read this issue more carefully, seems like a different problem but the pattern I use above isn't uncommon so hopefully it helps someone in a similar position!