Tree-sitter in Neovim without nvim-treesitter

nvim-treesitter.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

require "fileutils"
require "tmpdir"

TREESITTER_DIR = File.expand_path("~/.local/share/nvim/treesitter")
PARSER_DIR = File.join(TREESITTER_DIR, "parser")
QUERIES_DIR = File.join(TREESITTER_DIR, "queries")

PARSERS = {
  "html" => "tree-sitter/tree-sitter-html",
  "lua" => "tree-sitter-grammars/tree-sitter-lua",
  "python" => "tree-sitter/tree-sitter-python",
  "query" => "nvim-treesitter/tree-sitter-query",
  "ruby" => "tree-sitter/tree-sitter-ruby",
  "toml" => "tree-sitter-grammars/tree-sitter-toml",
  "tsx" => "tree-sitter/tree-sitter-typescript:tsx",
  "typescript" => "tree-sitter/tree-sitter-typescript:typescript",
  "vimdoc" => "neovim/tree-sitter-vimdoc",
  "yaml" => "tree-sitter-grammars/tree-sitter-yaml"
}.freeze

def run(*cmd)
  system(*cmd) || abort("error: command failed: #{cmd.join(" ")}")
end

def check_tree_sitter!
  return if system("command", "-v", "tree-sitter", out: File::NULL, err: File::NULL)
  abort("error: tree-sitter-cli not found -- run: brew install tree-sitter")
end

def build_parser(lang, force: false)
  existing = Dir.glob(File.join(PARSER_DIR, "#{lang}.{dylib,so}")).first
  if existing && !force
    puts("    parser -> #{existing} (cached)")
    return
  end

  entry = PARSERS.fetch(lang, "tree-sitter/tree-sitter-#{lang}")
  repo, subdir = entry.split(":", 2)

  Dir.mktmpdir do |tmp|
    src = File.join(tmp, lang)
    run("git", "clone", "--depth=1", "https://github.com/#{repo}", src, "-q")

    build_dir = subdir ? File.join(src, subdir) : src
    Dir.chdir(build_dir) { run("tree-sitter", "build") }

    parser_file = Dir.glob(File.join(build_dir, "*.{dylib,so}")).first
    abort("error: no parser file found after build for '#{lang}'") unless parser_file

    dest = File.join(PARSER_DIR, "#{lang}#{File.extname(parser_file)}")
    FileUtils.cp(parser_file, dest)
    puts("    parser -> #{dest}")
  end
end

def install(langs, force: false)
  abort("usage: nvim-treesitter install <lang> [<lang>...]") if langs.empty?
  check_tree_sitter!
  FileUtils.mkdir_p([QUERIES_DIR, PARSER_DIR])

  puts("Fetching queries...")
  Dir.mktmpdir do |tmp|
    clone_dir = File.join(tmp, "nvim-treesitter")
    paths = langs.map { |l| "runtime/queries/#{l}" }
    run(
      "git",
      "clone",
      "--depth=1",
      "--filter=blob:none",
      "--sparse",
      "https://github.com/nvim-treesitter/nvim-treesitter",
      clone_dir,
      "-q"
    )
    run("git", "-C", clone_dir, "sparse-checkout", "set", *paths)

    langs.each do |lang|
      src = File.join(clone_dir, "runtime/queries", lang)
      dest = File.join(QUERIES_DIR, lang)

      if !Dir.exist?(src)
        warn("  warning: no queries found for '#{lang}' in nvim-treesitter")
      elsif !Dir.exist?(dest) || force
        FileUtils.cp_r(src, dest)
        puts("  + #{lang}")
      end
    end
  end

  puts("Building parsers...")
  langs.each do |lang|
    puts("  #{lang}")
    build_parser(lang, force: force)
  end

  puts("\nDone!")
end

def sync(force: false)
  install(PARSERS.keys, force: force)
end

case ARGV.shift
when "sync"
  sync(force: ARGV.delete("--force"))
when "install"
  install(ARGV)
else
  puts(
    <<~USAGE
      nvim-treesitter -- manage tree-sitter parsers and queries for Neovim

      Usage:
        nvim-treesitter sync [--force]       fetch all queries + build parsers
        nvim-treesitter install <lang>...    fetch queries + build parser for specific language(s)

      Add to init.lua:
        vim.opt.runtimepath:prepend(vim.fn.expand("~/.local/share/nvim/treesitter"))
    USAGE
  )
end

This script downloads the parsers from their respective repos and pulls in the queries from the archived nvim-treesitter, building them with Tree-sitter.

Ensure the parsers are available in your Neovim config with:

vim.opt.runtimepath:prepend(vim.fn.expand("~/.local/share/nvim/treesitter"))

and ensure you're starting Tree-sitter in Neovim with:

vim.api.nvim_create_autocmd("FileType", {
  callback = function(args)
    pcall(vim.treesitter.start, args.buf)
  end,
})