For medium post

useControllableState.test.tsx

interface UsageProps {
  value?: number;
  changeHandler?: (value: number) => number | void;
}

function Counter({value, changeHandler}: UsageProps) {
  const [valueState, setValue] = useControllableState(value, changeHandler, 0);

  return <div>
    <span className="value">{valueState}</span>
    <button className="btn" onClick={() => setValue(valueState + 1)}>Increase</button>
  </div>
}