gistfile1.txt

Friend.findOne({
    userId: req.signedCookies.userid
}, function (err, signedInUser) {
    var friends = signedInUser.friends.map(
        function (a) { return { user: a, type: 'friend' }; }
    ),

    sentRequests = signedInUser.request_sent_to.map(
        function (a) { return { user: a, type: 'sent' }; }
    ),

    receivedRequests = signedInUser.request_received_from.map(
        function (a) { return { user: a, type: 'received' }; }
    );

    var res = [ { user: signedInUser, type: 'self' } ]
           .concat(friends)
           .concat(sentRequests)
           .concat(receivedRequests);

    // weed out any duplicates (erroneous!)
    var seen = [];
    res = res.filter(function (a) {
        if (seen.indexOf(a) === -1) {
            seen.push(a);
            return true;
        }
        console.error('Friend state error:', {
            'self': loggedInUser,
            'culprit': a
        });
        return false;
    });

    doSomethingWith(res);
});