SOURCE

const dom = document.getElementById('list')
console.log('aaa', dom.scrollHeight)

dom.addEventListener('scroll', e => {
    console.log('bbb', dom.scrollTop, dom.clientHeight)
})

<div id="list" class="list">
    <div class="item">1</div>
    <div class="item">1</div>
    <div class="item">1</div>
    <div class="item">1</div>
    <div class="item">1</div>
</div>

.list {
    height: 50px;
    background: red;
    overflow: auto;
    padding: 10px;
}
.item {
    height: 20px;
    border: 1px solid black;
    background: yellow;
}