The advent of async/await for Node.js - Node.js v7 has now arrived

By: (plus.google.com) +David Herron; Date: 2016-10-25 08:35

Tags: Node.JS » Asynchronous Programming

With today's first release of Node.js version 7, we now have async/await as a base feature of the platform. This is a significant milestone that wasn't even mentioned in the commit message. The async/await feature is so important that I'm preparing a short book to discuss JavaScript asynchronous programming patterns, that highly features async/await.

$ nvm install 7
Downloading https://nodejs.org/dist/v7.0.0/node-v7.0.0-darwin-x64.tar.xz...
######################################################################## 100.0%

That's how easy it is now to install Node.js version 7, if you have nvm installed. Implementing async/await is just a command line option away.

'use strict';

const fs    = require('fs-extra-promise');
const util  = require('util');

async function twofiles() {
    var texts = [
        await fs.readFileAsync('hello.txt', 'utf8'),
        await fs.readFileAsync('goodbye.txt', 'utf8')
    ];
    console.log(util.inspect(texts));
}

twofiles();

Try this code ... Run npm init to generate a package.json, and then: npm install fs-extra-promise --save

Finally, put suitable text into hello.txt and goodbye.txt ...

Your first attempt at running this might result in this:

$ node  2files.js
/Users/david/ebooks/Callbacks-Promises-Async/examples/asyncawait/2files.js:6
async function twofiles() {
      ^^^^^^^^
SyntaxError: Unexpected token function
    at Object.exports.runInThisContext (vm.js:76:16)
    at Module._compile (module.js:545:28)
    at Object.Module._extensions..js (module.js:582:10)
    at Module.load (module.js:490:32)
    at tryModuleLoad (module.js:449:12)
    at Function.Module._load (module.js:441:3)
    at Module.runMain (module.js:607:10)
    at run (bootstrap_node.js:382:7)
    at startup (bootstrap_node.js:137:9)
    at bootstrap_node.js:497:3

That's because you're missing a flag. The async/await feature is behind a --harmony flag. Run this instead:

$ node --harmony-async-await 2files.js
[ 'Hello, world!\n', 'Goodbye, world!\n' ]

Have fun. Ponder the code above. It is so fetchingly simple, yet does asynchronous execution. This is our future. I'll shortly have an initial version of my book available.

« Memory-efficient CSV transformation in Node.js Easily import your CSV data into MySQL with Node.js »
2016 Election Acer C720 Ad block AkashaCMS Amazon Amazon Kindle Amiga Android Anti-Fascism Apple Apple Hardware History Apple iPhone Apple iPhone Hardware April 1st Arduino ARM Compilation Astronomy Asynchronous Programming Authoritarianism Automated Social Posting Ayo.JS Bells Law Big Brother Big Finish Black Holes Blade Runner Blogger Blogging Books Botnet Botnets Cassette Tapes Cellphones Christopher Eccleston Chrome Chrome Apps Chromebook Chromebooks Chromebox ChromeOS CIA CitiCards Citizen Journalism Civil Liberties Clinton Cluster Computing Command Line Tools Computer Hardware Computer Repair Computers Cross Compilation Crouton Curiosity Rover Cyber Security Cybermen Daleks Darth Vader Data backup Data Storage Database Database Backup Databases David Tenant DDoS Botnet Detect Adblocker Developers Editors Digital Photography DIY DIY Repair DNP3 Docker Doctor Who Doctor Who Paradox Drobo Drupal Drupal Themes DVD E-Books E-Readers Early Computers Election Hacks Electric Bicycles Electric Vehicles Electron Emdebian Energy Efficiency Enterprise Node EPUB ESP8266 Ethical Curation Eurovision Event Driven Asynchronous Express Facebook Fake News Fedora VirtualBox File transfer without iTunes FireFly Fraud Freedom of Speech Gallifrey git Gitlab GMAIL Google Google Chrome Google Gnome Google+ Government Spying Great Britain Heat Loss Hibernate Home Automation HTTPS I2C Protocol Image Analysis Image Conversion Image Processing ImageMagick InfluxDB Infrared Thermometers Insulation Internet Internet Advertising Internet Law Internet of Things Internet Policy Internet Privacy iOS Devices iPad iPhone iPhone hacking Iron Man Iternet of Things iTunes Java JavaScript JavaScript Injection JDBC John Simms Journalism Joyent Kindle Marketplace Lets Encrypt LibreOffice Linux Linux Hints Linux Single Board Computers Logging Mac OS Mac OS X MacOS X setup Make Money Online MariaDB Mars Matt Lucas MEADS Anti-Missile Mercurial Michele Gomez Micro Apartments Military Hardware Minification Minimized CSS Minimized HTML Minimized JavaScript Missy Mobile Applications MODBUS Mondas MongoDB Mongoose Monty Python MQTT Music Player Music Streaming MySQL NanoPi Nardole NASA Net Neutrality Node Web Development Node.js Node.js Database Node.js Testing Node.JS Web Development Node.x North Korea Online advertising Online Fraud Online Journalism Online Video Open Media Vault Open Source Governance Open Source Licenses Open Source Software OpenAPI OpenVPN Personal Flight Peter Capaldi Photography PHP Plex Plex Media Server Political Protest Postal Service Power Control Privacy Production use Public Violence Raspberry Pi Raspberry Pi 3 Raspberry Pi Zero Recycling Remote Desktop Republicans Retro-Technology Reviews Right to Repair River Song Robotics Rocket Ships RSS News Readers rsync Russia Russia Troll Factory SCADA Scheme Science Fiction Season 1 Season 10 Season 11 Security Security Cameras Server-side JavaScript Shell Scripts Silence Simsimi Skype Social Media Warfare Social Networks Software Development Space Flight Space Ship Reuse Space Ships SpaceX Spear Phishing Spring Spring Boot SQLite3 SSD Drives SSD upgrade SSH SSH Key SSL Swagger Synchronizing Files Telescopes Terrorism The Cybermen The Daleks The Master Time-Series Database Torchwood Total Information Awareness Trump Trump Administration Ubuntu UDOO Virtual Private Networks VirtualBox VLC VNC VOIP Web Applications Web Developer Resources Web Development Web Development Tools Web Marketing Website Advertising Weeping Angels WhatsApp Window Insulation Wordpress YouTube