base.js

exports.searchContactPost = function(req, res) {
  if(req.body.searchContacts === '') { res.send('Oops you searching for nothing, well here is nothing!'); };
  async.waterfall([
                  function(callback) {
    User.find({$or:[
              {firstName: req.body.searchContacts.toLowerCase()},
              {lastName: req.body.searchContacts.toLowerCase()},
              {email: req.body.searchContacts.toLowerCase()}]
    }, function(err, users) {
      if(err || users.length === 0) { res.send(err);}
      callback(null, users)

    });
  },

  function(users, callback) {
    var userMap = {};
    var friendIds = users.map(function (user) {
      userMap[user._id] = user;
      return user._id;
    });
    Friend.find({userId: req.signedCookies.userid, friend_id: {$in: friendIds}, friend_status: 3}, function(err, friends) {
      if(err || !friends.length) {
        console.log("houston we got a problem.")
        return callback(err)
      }

      friends = friends.map(function (friend) {
        return userMap[friend._id];
      });

      callback(null, friends);
    });
  }

  ],

  function(err, results) {
    console.log(results);
    res.render('contactListResults', {title: 'Weblio', friendsFound: results});

  });

};