请简单实现双向数据绑定mvvm

const data = {};
const input = document.getElementById('input');
const span= document.getElementById('span');
Object.defineProperty(data, 'text', {
  set(value) {
    input.value = value;
    this._value = value;
  },
  get(){
    span.innerText= this._value
  }
});
input.onchange = function(e) {
  data.text = e.target.value;
}