/**
 *
 * @param {number} delay - milliseconds to delay the call
 * @param {function} fn - the callback to be fired when delay fires
 * @return {function} a function to call multiple times
 */
module.exports = function debounce(delay, fn) {
  if (typeof delay !== 'number') {
    throw new Error('you must pass in a number');
  }

  if (typeof fn !== 'function') {
    throw new Error('you must pass in a function');
  }

  let timer;

  return function () {
    clearTimeout(timer);
    timer = setTimeout.apply(setTimeout, [fn, delay, ...arguments]);
  };
};