Treesitter postfix snippet only expand correctly when `trig` is wholly matched

[sharpchen]

In the following example, treesitter_postfix snippet only expand correctly when type .var, any fuzzy match such as .v would capture nil for @prefix.

• completion: blink.cmp

• snippet:

  luasnip/cs.lua

  local ls = require('luasnip')
  local snip = ls.snippet --[[@as fun(trigger: string | { trig: string, name: string, desc: string }, node: any[] | any)]]
  local ins = ls.insert_node --[[@as fun(idx: integer, placeholder?: string)]]
  local fn = ls.function_node
  local sn = ls.snippet_node
  local dyn = ls.dynamic_node
  local fmt = require('luasnip.extras.fmt').fmt --[[@as fun(body: string, nodes: any[] | any, opts?: table)]]
  local rep = require('luasnip.extras').rep --[[@as fun(idx: integer)]]
  local text = ls.text_node
  local ref = require('luasnip.extras').lambda
  local postfix = require('luasnip.extras.postfix').postfix
  local ts_post = require('luasnip.extras.treesitter_postfix').treesitter_postfix
  local postfix_builtin = require('luasnip.extras.treesitter_postfix').builtin
  
  return {
    ts_post({
      trig = '.var',
      matchTSNode = {
        query = [[
              [
                (invocation_expression)
                (member_access_expression)
                (identifier)
              ] @prefix
          ]],
        query_lang = 'c_sharp',
        match_captures = { 'prefix' },
      },
    }, {
      dyn(1, function(_, parent)
        local node_content = parent.snippet.env.LS_TSCAPTURE_PREFIX
        if type(node_content) == 'table' then
          node_content = table.concat(node_content, '\n')
        end
        return sn(nil, fmt('var {} = {};', { ins(1), text(node_content) }))
      end),
    }),
  }