Simple underscore function to create secure "inmutable" (recursive deep copy) JavaScript Objects

deep-clone-underscore.js

  /**
   * Simple underscore function to create secure inmutable (recursive deep copy) JavaScript Objects 
   * @param {Object/Array} obj Target Object. Required
   * @param {Number} depth Depth level. Defaults to 1
   * @return {Object/Array) Super inmutable new Object
   * @method deepClone
   */
  _.deepClone = function deepClone(obj, depth) {
    var clone, key;
    depth = depth || 1;
    if (typeof obj !== 'object' || obj === null) { return obj; }
    if (_.isString(obj)) { return obj.splice(); }
    if (_.isDate(obj)) { return new Date(obj.getTime()); }
    if (_.isFunction(obj.clone)) { return obj.clone(); }
    clone = _.isArray(obj) ? obj.slice() : _.extend({}, obj);
    if (depth !== undefined && depth > 0) {
      for (key in clone) {
          clone[key] = deepClone(clone[key], depth-1);
      }
    }
    return clone;
  }