Upgrading the nvim-treesitter plugin

Every couple of weeks, I run MiniDeps’s :DepsUpdate and cross my fingers that everything is going to be fine. Most of the time it is but not this morning¹.

Immediately, I got the following errors:

Error detected while processing ~/.config/nvim/init.lua:
E5113: Error while calling lua chunk: ~/.config/nvim/lua/_/ui/treesitter.lua:1: module 'nvim-treesitter.configs' not found:
        no field package.preload['nvim-treesitter.configs']
        no file '/nix/store/w997z7g0ii6figi4z98id0b0yn2jzala-luajit-2.1.1741730670-env/share/lua/5.1/nvim-treesitter/configs.lua'
        no file '/nix/store/w997z7g0ii6figi4z98id0b0yn2jzala-luajit-2.1.1741730670-env/share/lua/5.1/nvim-treesitter/configs/init.lua'
        no file '/nix/store/bmdviv9ljgqb6siq2p3dsll497fjzpif-luajit2.1-fzy-1.0.3-1/share/lua/5.1/nvim-treesitter/configs.lua'
        no file '/nix/store/bmdviv9ljgqb6siq2p3dsll497fjzpif-luajit2.1-fzy-1.0.3-1/share/lua/5.1/nvim-treesitter/configs/init.lua'
        no file '/nix/store/w997z7g0ii6figi4z98id0b0yn2jzala-luajit-2.1.1741730670-env/lib/lua/5.1/nvim-treesitter/configs.so'
        no file '/nix/store/bmdviv9ljgqb6siq2p3dsll497fjzpif-luajit2.1-fzy-1.0.3-1/lib/lua/5.1/nvim-treesitter/configs.so'
        no file '/nix/store/w997z7g0ii6figi4z98id0b0yn2jzala-luajit-2.1.1741730670-env/lib/lua/5.1/nvim-treesitter.so'
        no file '/nix/store/bmdviv9ljgqb6siq2p3dsll497fjzpif-luajit2.1-fzy-1.0.3-1/lib/lua/5.1/nvim-treesitter.so'

Investigating further, I saw that the master branch of nvim-treesitter is now frozen and they’re now working on the main branch. The new branch is a complete rewrite. The fix could have been a simple:

  MiniDeps.add({
    source = 'nvim-treesitter/nvim-treesitter',
-   checkout = 'master',
+   checkout = 'main',
    hooks = { post_checkout = function() vim.cmd('TSUpdate') end },
  })

However, since I was there and I figured I’ll just do the update properly. First, my configuration looked like this:

local configs = require('nvim-treesitter.configs')
local mdx = require('mdx')

---@diagnostic disable-next-line: missing-fields
configs.setup({
  auto_install = true,
  highlight = { enable = true },
  endwise = { enable = true },
  indent = { enable = true },
})

The rewrite removes the need for manual config except for customization on where the parsers are installed. To keep the behaviours I had before, in my case, the auto_install option and the highlighting, I update my config like this:

1. First, I installed parsers for files in my dotfile on startup. Thankfully, this is a no-op when they’re already installed:

local ts = require('nvim-treesitter')

-- Wait at most 30 seconds to finish installation.
ts.install(
  {
    'lua', 'vim', 'vimdoc', 'query',
    'markdown', 'markdown_inline',
    'json', 'yaml',
  },
  -- Do not print summary, as this will run at startup always, all the time.
  { summary = false }
):wait(30000)

2. Then, I install the parser and enable highlighting and other plugin using an autocmd that triggers on FileType:

---@type fun(args: vim.api.keyset.create_autocmd.callback_args): boolean?
local install_parser_and_enable_features = function(event)
  local lang = event.match

  -- Try to start the parser install for the language.
  local ok, task = pcall(ts.install, { lang }, { summary = true })
  if not ok then return end

  -- Wait for the installation to finish (up to 10 seconds).
  task:wait(10000)

  -- Enable syntax highlighting for the buffer
  ok, _ = pcall(vim.treesitter.start, event.buf, lang)
  if not ok then return end

  -- Enable other features as needed.

  -- Enable indentation based on treesitter for the buffer.
  -- vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"

  -- Enable folding based on treesitter for the buffer.
  -- vim.wo.foldexpr = 'v:lua.vim.treesitter.foldexpr()'
end

-- Install missing parsers on file open.
vim.api.nvim_create_autocmd('FileType', {
  group = vim.api.nvim_create_augroup('ui.treesitter', { clear = true }),
  pattern = { '*' },
  callback = install_parser_and_enable_features
})

And like that, no more errors and treesitter works as expected. I should probably read more about the reasons of the rewrite, but I’ll leave this for another Friday.