Neovim Tree-Sitter node motion

node_motion.lua

local api = vim.api
local ctrlv = api.nvim_replace_termcodes('<C-V>', true, true, true)

local function exit_vmode()
  local mode = vim.fn.mode()
  if mode == 'v' or mode == 'V' or mode == ctrlv then
    vim.cmd('normal! ' .. mode)
  end
end

---Motion over the best-match named node under the cursor/selection.
local function node_motion()
  local bufnr = api.nvim_win_get_buf(0)
  local ok, lang_tree = pcall(vim.treesitter.get_parser, bufnr)
  if not ok then return end

  local cpos = api.nvim_win_get_cursor(0)
  local vpos = vim.fn.getpos('v')
  local node = lang_tree:named_node_for_range(
    { vpos[2] - 1, vpos[3] - 1, cpos[1] - 1, cpos[2] + 1 },
    { ignore_injections = false }
  )
  if not node then return end

  exit_vmode()
  local start_row0, start_col0, end_row0, end_col0 = node:range()
  api.nvim_win_set_cursor(0, { start_row0 + 1, start_col0 })
  vim.cmd('normal! v')
  if node:parent() then
    api.nvim_win_set_cursor(0, { end_row0 + 1, end_col0 - 1 })
  else
    -- It is the root node, so avoid setting the cursor position outside of
    -- buffer.
    vim.cmd('normal! G$h')
  end
end

vim.keymap.set({ 'x', 'o' }, 'n', function() node_motion() end)