Debounce & Throttle

debounce.js

/*
 * Call dembounced function only after `limit` amount of time
 * has passed since the last call. The limit resets if the function is called
 * before before `limit` amount of duraction has passed from the last call.
 * This impliesa delay between the last event and handle function call.
 */
export default customDebounce (func, limit) {
  let timeout;
  return debouncedFunction () {
    let context = this, args = arguments;
    const effect = () => {
      timeout = null;
      func.apply(context, args);
    };
    clearTimeout(timeout);
    timeout = setTimeout(effect, limit);
  };
}

throttle.js

/*
 * Call throttled function only once per `limit` amount of time.
 * Every other call in between is rejected or ignored.
 */
export default customThrottle (func, limit) {
  let flag = true;
  return function throttledFunc () {
    let context = this, args = arguments;
    if (flag) {
      func.apply(context, args);
      flag = false;
      setTimeout(() => {
        flag = true;
      }, limit);
    }
  }
}

References:

1. Debounce vs Throttle by Artem Zakharchenko
2. Lodash Debounce
3. Lodash Throttle
4. CSS Tricks

Lodash implements Throttle using their Debounce implementation.