underscore merge function

underscore_merge.js

var _ = require('lodash');

var obj1 = {foo:'bar',baz:'bang', arr:[1,3,5,7], objecter : { 'connor' : 2, 'sky':'toot', 'new':'dude' } };
var obj2 = {foo:'bar',baz:'bang', arr:[2,4,6,8], newz:1, objecter : { 'sky' : 'mills'} };

merge(obj1,obj2);
merge(null,2);
merge(4,6);

console.log(obj1);

/* object 1 rules */
function merge(obj1, obj2) {
  var type1 = getType(obj1);
  var type2 = getType(obj2);

  if ( type1 !== type2 ) {
    return;
  }
  if ( _.isEqual(obj1,obj2) ) {
    return;
  }

  if ( type1 === 'array' ) {
    _.each(obj2, function(obj2item) {
      if ( _.indexOf(obj1, obj2item) < 0 ) {
        obj1.push(obj2item);
      }
    });
  } else if ( type1 === 'object' ) {
    _.each(obj2, function(obj2item, obj2key) {
      if ( ! _.has(obj1, obj2key) ) {
        obj1[obj2key] = obj2item;
      } else {
        var merged = merge(obj1[obj2key], obj2item);
      } 
    });
  }
}

function getType (val) {
  if (typeof val === 'undefined') return 'undefined';
  if (typeof val === 'object' && !val) return 'null';
  return ({}).toString.call(val).match(/\s([a-zA-Z]+)/)[1].toLowerCase();
}