Is there a callback for window.scrollTo?

I wrote a generic function based on the solution of George Abitbol, without overwriting window.onscroll:

/**
 * Native scrollTo with callback
 * @param offset - offset to scroll to
 * @param callback - callback function
 */
function scrollTo(offset, callback) {
    const fixedOffset = offset.toFixed();
    const onScroll = function () {
            if (window.pageYOffset.toFixed() === fixedOffset) {
                window.removeEventListener('scroll', onScroll)
                callback()
            }
        }

    window.addEventListener('scroll', onScroll)
    onScroll()
    window.scrollTo({
        top: offset,
        behavior: 'smooth'
    })
}

I found a way to achieve what I want but I think it's a bit hacky, isn't it?

let el = document.getElementById('input')
let elScrollOffset = el.getBoundingClientRect().top
let scrollOffset = window.pageYOffset || document.documentElement.scrollTop
let padding = 12
let target = elScrollOffset + scrollOffset - padding
window.scrollTo({
  top: target,
  behavior: 'smooth'
})
window.onscroll = e => {
  let currentScrollOffset = window.pageYOffset || document.documentElement.scrollTop
  // Scroll reach the target
  if (currentScrollOffset === target) {
    el.focus()
    window.onscroll = null // remove listener
  }
}