Calculate distance between elements

distance.js

const getPositionAtCenter = function (element) {
  let data = element.getBoundingClientRect();
  return {
    x: data.left + data.width / 2,
    y: data.top + data.height / 2
  };
};

const getDistanceBetweenElements = function(a, b) {
  let aPosition = getPositionAtCenter(a);
  let bPosition = getPositionAtCenter(b);

  return Math.sqrt(
    Math.pow(aPosition.x - bPosition.x, 2) + 
    Math.pow(aPosition.y - bPosition.y, 2) 
  );
};