Promise.join with arrow function

promise-with-arrows.js

/**
 * This does not work on node v4.2.0
 * 
 * Reason has been determined. The first example of arrow functions is a function 
 * definition, not a function call. The second is a function call that passes the 
 * return value to Promise.join
 */
'use strict';

const Promise = require('bluebird');
const models = require('../database');

const resource = {
	browse: function browse() {
		return Promise.join(
			() => models.table_one.findAll(),
			() => models.table_two.findAll(),
			() => models.table_three.findAll(),
			function(table_one, table_two, table_three) {
				const response = {
					table_one,
					table_two,
					table_three,
				};

				return response;
			});
	},
};

module.exports = resource;

/**
 * But this does
 */
'use strict';

const Promise = require('bluebird');
const models = require('../database');

const resource = {
	browse: function browse() {
		function getTableOne() {
			return models.table_one.findAll();
		}

		function getTableTwo() {
			return models.table_two.findAll();
		}

		function getTableThree() {
			return models.table_three.findAll();
		}
		return Promise.join(
				getTableOne(),
				getTableTwo(),
				getTableThree(),
				function(table_one, table_two, table_three) {
					const response = {
						table_one,
						table_two,
						table_three,
					};

					return response;
				});
	},
};

module.exports = resource;