Function getBordersSize

app/src/static/js/react-bootstrap.js:3322–3326

(styles, axis)

function getBordersSize(styles, axis) {
  var sideA = axis === 'x' ? 'Left' : 'Top';
  var sideB = sideA === 'Left' ? 'Right' : 'Bottom';
  return parseFloat(styles['border' + sideA + 'Width'], 10) + parseFloat(styles['border' + sideB + 'Width'], 10);
}

function getSize(axis, body, html, computedStyle) {
  return Math.max(body['offset' + axis], body['scroll' + axis], html['client' + axis], html['offset' + axis], html['scroll' + axis], isIE(10) ? parseInt(html['offset' + axis]) + parseInt(computedStyle['margin' + (axis === 'Height' ? 'Top' : 'Left')]) + parseInt(computedStyle['margin' + (axis === 'Height' ? 'Bottom' : 'Right')]) : 0);