Element animator for jQuery

jquery.animator.js

/**
 * Element fadeIn plugin for jQuery.
 * @author Stefan Aichholzer <https://github.com/aichholzer>
 * @param options -Object defining the animation's end result.
 *
 * {
 *   opacity: 1,
 *   marginBottom: 5,
 *   duration: 50
 * }
 */
(function ($) {
  $.fn.animator = function animator(options = null) {
    if (!options) {
      return this;
    }

    this.toArray()
      .map(item => () => $(item).animate(options, options.duration).promise())
      .reduce((current, next) => current.then(next), $().promise());
  };
}(jQuery));