Debounce a function firing

debounce.js

/**
 * Debounce a function firing
 * @param {function} func The function to potentially fire
 * @param {number} wait Debounced wait duration (millisecs)
 * @param {boolean} immediate Should leading occurrence exec fn immediately
 * @return {void}
 */
debounce = function(func, wait, immediate) {
  var timeout;
  return function() {
    var context = this, args = arguments;
    var later = function() {
      timeout = null;
      if (!immediate) {
        func.apply(context, args);
      }
    };
    var callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait);
    if (callNow) {
      func.apply(context, args);
    }
  };
};