x.js

var UserCollection = require("../dataSources/user")

var User = {
    find: function( name, skypeName, callback ) {
        if ( skypeName ) {
            findBySkypeName( name, callback );
        }
        // The rest of your logic there
    }
}

function findBySkypeName( name, callback ) {
    UserCollection.getBySkypeName( name, function( err, user ) {
        if ( !user ) {
            return UserCollection.createFromSkypeName(name, callback);
        }
        return callback( null, user );
    }
}