temp.js

const findLastRowWithValue = (sheet) => {
  const { decode_cell } = XLSX.utils;
  const { r } = decode_cell(sheet['!ref'].split(':')[1]);
  const isEmpty = (x) => sheet[`A${ x }`].v === undefined;

  let start = 1;
  let end = r + 1;
  let pivot = Math.round((end - start) / 2);

  if (pivot === 0) {
    log.error({start,end,pivot})
    return !isEmpty(start) ? start : null;
    //return start;
  }

  let iterations = 10;

  while (true) {
    if (iterations == 0) {
      break;
    }

    log.debug({
      start: [start,isEmpty(start)],
      pivot: [pivot,isEmpty(pivot)],
      end: [end,isEmpty(end)],
    })

    // base condition
    if (pivot === end && !isEmpty(pivot - 1) && isEmpty(pivot)) {
      return pivot - 1;
    }

    if (isEmpty(pivot)) {
      end = pivot;
      pivot = Math.round((pivot + start) / 2);
    } else {
      start = pivot;
      pivot = Math.round((end + pivot) / 2);
    }
    iterations--;
  }

  return pivot;
}