Как я могу прочитать текущее значение textarea.rows и cols?

const getRows = textarea => {
  const computedStyle = getComputedStyle(textarea);
  const { offsetWidth: realOffsetWidth, scrollWidth: realScrollWidth } =
    getSize(textarea);
  const realScrollbarWidth = realOffsetWidth - realScrollWidth;

  const tempElement = document.createElement('textarea');

  tempElement.rows = 1;
  tempElement.style.font = computedStyle.font;
  tempElement.style.border = computedStyle.border;
  tempElement.style.padding = computedStyle.padding;
  tempElement.style.lineHeight = computedStyle.lineHeight;
  tempElement.style.overflowY = 'scroll';
  tempElement.style.position = 'absolute';
  tempElement.style.visibility = 'hidden';

  document.body.appendChild(tempElement);

  const { offsetWidth, scrollWidth } = getSize(tempElement);
  const scrollbarWidth = offsetWidth - scrollWidth;
  tempElement.style.width = realScrollbarWidth
    ? realOffsetWidth + 'px'
    : realOffsetWidth + scrollbarWidth + 'px';

  tempElement.textContent = textarea.value;

  const { offsetHeight, scrollHeight } = getSize(tempElement);

  document.body.removeChild(tempElement);

  return Math.floor(scrollHeight / offsetHeight);
};

const getSize = el => {
  const computedStyle = getComputedStyle(el);
  const paddingTop = parseFloat(computedStyle.paddingTop);
  const paddingBottom = parseFloat(computedStyle.paddingBottom);
  const paddingLeft = parseFloat(computedStyle.paddingLeft);
  const paddingRight = parseFloat(computedStyle.paddingRight);
  const borderTop = parseFloat(computedStyle.borderTopWidth);
  const borderBottom = parseFloat(computedStyle.borderBottomWidth);
  const borderLeft = parseFloat(computedStyle.borderLeftWidth);
  const borderRight = parseFloat(computedStyle.borderRightWidth);

  const offsetHeight =
    el.offsetHeight - paddingTop - paddingBottom - borderTop - borderBottom;
  const scrollHeight = el.scrollHeight - paddingTop - paddingBottom;
  const offsetWidth =
    el.offsetWidth - paddingLeft - paddingRight - borderLeft - borderRight;
  const scrollWidth = el.scrollWidth - paddingLeft - paddingRight;

  return { offsetHeight, scrollHeight, offsetWidth, scrollWidth };
};

output.textContent = getRows(textarea);

textarea.addEventListener('input', function () {
  output.textContent = getRows(this);
});

const resizeObserver = new ResizeObserver(() => {
  output.textContent = getRows(textarea);
});
resizeObserver.observe(textarea);

<p>
How can I read the current textarea rows and cols?
</p>
<textarea id = "textarea">how big
am I?</textarea>
<div id = "output"></div>