attempt to index field 'effective_child_ext_opts' (a nil value)

[sharpchen]

I was trying to make a wrapper for creating simple snippet by fmt.

The wrapper is pretty long

  --- simple snippet definition
  --- only for snippets have successive index
  --- use <> as delimiters by default
  ---@param filetype string | string[]
  ---@param trigger string | { trig: string, name: string, desc: string }
  ---@param body string
  ---@param opts? { delimiters?: string }
  M.snippet.add = function(filetype, trigger, body, opts)
    local ok, ls = pcall(require, 'luasnip')
    if not ok then return end
    local snip = ls.snippet --[[@as fun(trigger: string | { trig: string, name: string, desc: string }, node: any[] | any)]]
    local insert = ls.i --[[@as fun(idx: integer, placeholder: string)]]
    local fmt = require('luasnip.extras.fmt').fmt --[[@as fun(body: string, nodes: any[] | any, opts: table)]]

    opts = (opts and opts.delimiters) and opts or { delimiters = '<>' }
    local l, r = opts.delimiters:sub(1, 1), opts.delimiters:sub(2, 2)
    local placeholders = Collect(body:gmatch(l:verbatim() .. '(.-)' .. r:verbatim()))
    local body, count = body:gsub(l:verbatim() .. '.-' .. r:verbatim(), opts.delimiters)
    local nodes = {}

    for i = 1, count do
      table.insert(nodes, insert(i, placeholders[i]))
    end

    if type(filetype) == 'table' then
      for _, ft in ipairs(filetype) do
        ls.add_snippets(ft, {
          snip(trigger, fmt(body, nodes, opts)),
        })
      end
    else
      ls.add_snippets(filetype, {
        snip(trigger, fmt(body, nodes, opts)),
      })
    end

    vim.notify(vim.inspect(placeholders))
  end

-- the following are utils used in the wrapper
function string.verbatim(str)
  local regex = ('^$()%.[]*+-?'):to_array()
  local percent = '%'
  _G.my_regex_special = _G.my_regex_special
    or ('([%s])'):format(
      vim
        .iter(regex)
        :fold('', function(sum, current) return sum .. '%' .. current end)
    )
  local ret, _ = str
    :gsub('%%', '%%%%')
    :gsub(_G.my_regex_special, '%%%1')
    :gsub(percent:rep(8), percent:rep(4))
  return ret
end

---@generic TResult
---@return TResult[]
---@param iterator fun(): TResult
function Collect(iterator)
  local ret = {}
  for element in iterator do
    table.insert(ret, element)
  end
  return ret
end

The wrapper works fine for other uses, but error happens on following snippet:

M.snippet.add(
      { 'cs', 'typescript', 'javascript', 'lua' },
      'lambda',
      '([param]) => [/* body */]',
      { delimiters = '[]' }
    )

failed to resolve item with error: ...local/share/nvim/lazy/LuaSnip/lua/luasnip/nodes/node.lua:424: attempt to index field 'effective_chi
ld_ext_opts' (a nil value)

I am using blink.cmp, it shows following error:

blink.cmp  ERROR ...k.cmp/lua/blink/cmp/completion/windows/documentation.lua:66: attempt to index local 'item' (a ni
l value)

What's strange is that this error happens for filetype cs, javascript, typescript but works ok for lua and json. I have no idea what I did wrong, any particular mistake would cause this error? Please help!

[L3MON4D3]

Hi :)

I've tried your wrapper, and it seems to work as expected

-- the following are utils used in the wrapper
function string.verbatim(str)
  local regex = {"^","$","(",")","%",".","[","]","*","+","-","?",}
  local percent = '%'
  _G.my_regex_special = _G.my_regex_special
    or ('([%s])'):format(
      vim
        .iter(regex)
        :fold('', function(sum, current) return sum .. '%' .. current end)
    )
  local ret, _ = str
    :gsub('%%', '%%%%')
    :gsub(_G.my_regex_special, '%%%1')
    :gsub(percent:rep(8), percent:rep(4))
  return ret
end

---@generic TResult
---@return TResult[]
---@param iterator fun(): TResult
function Collect(iterator)
  local ret = {}
  for element in iterator do
    table.insert(ret, element)
  end
  return ret
end

--- simple snippet definition
--- only for snippets have successive index
--- use <> as delimiters by default
---@param filetype string | string[]
---@param trigger string | { trig: string, name: string, desc: string }
---@param body string
---@param opts? { delimiters?: string }
local add = function(filetype, trigger, body, opts)
  local ok, ls = pcall(require, 'luasnip')
  if not ok then return end
  local snip = ls.snippet --[[@as fun(trigger: string | { trig: string, name: string, desc: string }, node: any[] | any)]]
  local insert = ls.i --[[@as fun(idx: integer, placeholder: string)]]
  local fmt = require('luasnip.extras.fmt').fmt --[[@as fun(body: string, nodes: any[] | any, opts: table)]]

  opts = (opts and opts.delimiters) and opts or { delimiters = '<>' }
  local l, r = opts.delimiters:sub(1, 1), opts.delimiters:sub(2, 2)
  local placeholders = Collect(body:gmatch(l:verbatim() .. '(.-)' .. r:verbatim()))
  local body, count = body:gsub(l:verbatim() .. '.-' .. r:verbatim(), opts.delimiters)
  local nodes = {}

  for i = 1, count do
    I(placeholders[i])
    table.insert(nodes, insert(i, placeholders[i]))
  end

  I(body)
  if type(filetype) == 'table' then
    for _, ft in ipairs(filetype) do
      ls.add_snippets(ft, {
        snip(trigger, fmt(body, nodes, opts)),
      })
    end
  else
    ls.add_snippets(filetype, {
      snip(trigger, fmt(body, nodes, opts)),
    })
  end

  vim.notify(vim.inspect(placeholders))
end

require("luasnip").add_snippets("all", {
	add(
		  { 'cs', 'typescript', 'javascript', 'lua' },
		  'lambda',
		  '([param]) => [/* body */]',
		  { delimiters = '[]' }
		)
}, { key = "043fd491-ba06-4133-a415-b858f1bf795e" })

Could you also try my code? I think there may be something else interfering.

I'm using the current master of luasnip, maybe that's a difference?

[sharpchen]

Hi, thanks for the review, unfortunately master reproduced the same error on my machine :|