RethinkDbConnection.js

var Promise = require('bluebird');
var rdb = Promise.promisify(require('rethinkdb'));

module.exports = function(config) {
    return {
        connectToDb: function(){
            return Promise.try(
                function(){
                    return rdb.connect(config);
                }
            )
        }
    }
}

testRethinkConnection.js

var Promise = require('bluebird');
var rdb = Promise.promisify(require('rethinkdb'));
var config = { host: "localhost", port: 28015 }
var RethinkDbConnection = require('./lib/RethinkDbConnection')(config).connectToDb();
var tableName = "testdb"; // <------ just for testing

var createTable = function(tableName){
    RethinkDbConnection.then( (connectionResult) => {
        rdb.db('test').tableCreate(tableName).run(connectionResult).then( (tableCreationResult) => {
            console.log(JSON.stringify(tableCreationResult, null, 2));
        });
    });
}

createTable(tableName);