SOURCE

const input = document.getElementById('input');
const span = document.getElementById('span');
const obj = {};
Object.defineProperty(obj, 'text', {
    configurable: true,
    enumerable: true,
    get() {
        console.log('hhaah');
    },
    set(val) {
        span.innerHTML = val;
        input.value = val;
        console.log('hhh')
    }
})
input.addEventListener("keyup", function(e) {
    obj.text = e.target.value;
})

<input id="input" type="text">
<span id="span"></span>