doc: use the correct way to check comment block

[Kaiser-Yang]

Using node:type() do not work as expected, sometimes, the type will go with a "chunk" or even empty string, we must iterate the node of current line to check if current line is inside a comment block. Besides, in the code, there is no ctx passed to the default function, just remove the parameter in the doc.

[Kaiser-Yang]

This works fine.

In non-comment context:

After I add --:

[saghen]

Sorry for the delay! I haven't gotten around to this one yet because it's quite a big recipe, to the point that I think we should include a utility function for it in the core. I'd also like to look into ways we can simplify this, if that's possible

[stefanboca]

You can replace the large if cases with vim.treesitter.node_contains(node, {row, col, row, col}).

You might also consider searching for an injected comment parser, instead of a specific node:

local function inside_comment_block()
  local ok, parser = pcall(vim.treesitter.get_parser)
  if not ok or not parser then return end
  local cursor = vim.api.nvim_win_get_cursor(0)
  local row, col = cursor[1] - 1, cursor[2]
  return parser:language_for_range({ row, col, row, col }):lang()
end

thought this only works for languages whose queries support comment injections, and only if the user has the comment parser installed.