TypeScript でライブラリを使わずに簡易 throttle, debounce

凝ったオプションを使いたい場合は lodash を使いましょう

throttle.ts

function throttle(fn: (...args: any[]) => void, wait: number) {
  let timerId: number | null = null;
  return (...args: any[]) => {
    if (timerId !== null) {
      return;
    }
    timerId = window.setTimeout(() => {
      timerId = null;
      return fn(...args);
    }, wait);
  };
}

debounce.ts

function debounce(fn: (...args: any[]) => void, wait: number) {
  let timerId: number | null = null;
  return (...args: any[]) => {
    if (timerId) {
      clearTimeout(timerId);
    }
    timerId = window.setTimeout(() => {
      fn(...args);
    }, wait);
  };
}