JavaScript Observable

js-observable.js

const debounce = (fn, ms = 0) => {
  let id;
  return (...args) => {
    if (id) clearTimeout(id);
    id = setTimeout(() => fn(...args), ms);
  };
};
const observable = (render) => {
  const that = {};
  const _render = debounce(render);
  const handler = {
    get(target, prop) {
      return target[prop];
    },
    set(target, prop, value) {
      if (target[prop] === value) return target;
      target[prop] = value;
      _render(target);
      return target;
    },
  };
  return new Proxy(that, handler);
};
const log = console.log.bind(null, new Date());
const state = observable(log);
state.b = "b";
state.b1 = "b1";
state.b2 = "b2";
state.b2 = "b2";
state.b3 = "b3";
log(state.b);