Add 2 numbers, fix floating point problem, example: 0.1 + 0.2, not support Node.js :Đ

add.js

function add(a, b) {
  if (a === 0) return b;
  if (b === 0) return a;
  let sign = 1;
  if (a < 0 && b < 0) {
    a = -a;
    b = -b;
    sign = -1;
  }
  if (b < 0) {
    [a, b] = [b, a];
  }
  const el = document.createElement('input');
  el.type = 'number';
  el.min = a;
  el.value = a;
  el.step = b;
  el.stepUp();
  return el.valueAsNumber * sign;
}