debounce.js

function debounce(fn, ms, obj){
  return Object.assign( function fx(...args){
    const now = Date.now();
    if(now - fx.lastCall > ms){
      fx.lastCall = now;
      return fx.fn.call(fx.obj,...args);
    }
    if(fx.timeout) clearTimeout(fx.timeout);
    fx.timeout = setTimeout(()=>fx(...args), fx.lastCall + ms - now);
  }, { fn, obj, lastCall: 0, timeout: null });
}