Total.js - Using Promise to get schema objects

totaljs-promise-schema.js

NEWSCHEMA('Form').make(function (schema) {
    schema.define('contact', 'FormContact', true);
    schema.define('deal', 'FormDeal', true);

    schema.addWorkflow('submit', function (error, model, options, callback, controller) {
        Promise.all([getDealById(options.deal_id), getContactById(options.contact_id)])
                    .then(function (values) {
                        let valid = (values[0] && value[1]); // 0 = getDealById, 1 = getContactById
                        if (!valid) {
                            error.push('deal', 'not found.');
                            return callback(model);
                        }

                        model.deal = values[0];
                        model.contact = value[1];
                        return callback(model);
                    }, function (err) {
                        // handle err, it was rejected by one or the other promise
                        error.push('email', err);
                        return callback(model);
                    }).catch(function (err) {
                        // handle err, unexpected error occured, e.g. unhandled exception
                        return callback(model);
                    });
    });

    function getContactById(id) {
        return new Promise(function (resolve, reject) {
            GETSCHEMA('Contact').get(id, function (err, data) {
                if (err) reject(err);
                else resolve(data);
            });
        })
    };

    function getDealById(id) {
        return new Promise(function (resolve, reject) {
            GETSCHEMA('Deal').get(id, function (err, data) {
                if (err) reject(err);
                else resolve(data);
            });
        })
    };
});