Remove all blocks in rtf fonttbl code

Remove all blocks in rtf code

function removeAllBlocksInRtfFonttblCode(rtf) {
  let newRtf = '', firstIndex, lastIndex, count, tagOpen = 1;
  firstIndex = rtf.indexOf('\\fonttbl');
  count = firstIndex;

  while(count < rtf.length && tagOpen > 0) {
    if(rtf[count] == '{')
      tagOpen++;
    else if(rtf[count] == '}') {
      if(tagOpen > 1)
        tagOpen--;
      else {
        tagOpen--;
        newRtf += rtf[count];
        lastIndex = count;
      }
    } else
        newRtf += rtf[count];
    count++;
  }
  return rtf.substring(0, firstIndex) + newRtf + rtf.substring(lastIndex+1);
}

if(rtf.indexOf("\fonttbl{") == -1){
return rtf;
}

let tokens = rtf.split("");
let tokensReverted = _.reverse(tokens);
if(tokensReverted[0] != "}"){
  let found  = false;
  tokensReverted = _.filter(tokensReverted, el=>{
    if(!found && el == "}") found = true;
    if(found){
      return el;
    }
  });
  tokens = _.reverse(tokensReverted);
  rtf = tokens.join("");
}