async parsing data URIs remotely (with nested promises)

datauris.js

var request = require('request');
var Promise = require('es6-promise').Promise;


var promisesApps = [];
promisesApps.push(new Promise(function (resolveApp, rejectApp) {
    var urls = [
        'https://marketplace-dev.mozflare.net/img/uploads/addon_icons/405/405402-64.png?modified=1384390457',
        'https://marketplace-dev.mozflare.net/img/uploads/previews/full/81/81268.png?modified=1368635236'
    ];

    var promisesDataUris = [];

    urls.forEach(function () {
        var req = request(urls[0]);

        promisesDataUris.push(new Promise(function (resolveDataUri, rejectDataUri) {
            req.end();
            req.on('response', function (res) {
                var body = '';
                var prefix = 'data:' + res.headers['content-type'] + ';base64,';

                res.setEncoding('binary');
                res.on('data', function (chunk) {
                    if (res.statusCode == 200) {
                        body += chunk;
                    }
                }).on('end', function () {
                    var base64 = new Buffer(body, 'binary').toString('base64');
                    var data = prefix + base64;
                    if (data) {
                        resolveDataUri(data);
                    } else {
                        rejectDataUri(data);
                    }
                }).on('error', function () {
                    rejectDataUri();
                });
            });
        }));
    });

    Promise.all(promisesDataUris).then(function (data) {
        console.log('data URIs done');
        resolveApp(data);
    }, function () {
        console.log('data URIs error');
        rejectApp();
    });
}));


Promise.all(promisesApps).then(function (data) {
    console.log('app done', data);
}, function () {
    console.log('app error');
});