Book Image

Advanced Node.js Development

By : Andrew Mead
Book Image

Advanced Node.js Development

By: Andrew Mead

Overview of this book

Advanced Node.js Development is a practical, project-based book that provides you with all you need to progress as a Node.js developer. Node is a ubiquitous technology on the modern web, and an essential part of any web developer’s toolkit. If you're looking to create real-world Node applications, or you want to switch careers or launch a side-project to generate some extra income, then you're in the right place. This book was written around a single goal: turning you into a professional Node developer capable of developing, testing, and deploying real-world production applications. There's no better time to dive in. According to the 2018 Stack Overflow Survey, Node is in the top ten for back-end popularity and back-end salary. This book is built from the ground up around the latest version of Node.js (version 9.x.x). You'll be learning all the cutting-edge features available only in the latest software versions. This book delivers advanced skills that you need to become a professional Node developer. Along this journey you'll create your own API, you'll build a full real-time web app and create projects that apply the latest Async and Await technologies. Andrew Mead maps everything out for you in this book so that you can learn how to build powerful Node.js projects in a comprehensive, easy-to-follow package designed to get you up and running quickly.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Handling errors and awaiting async function


We're going to kick this section off by converting both getExchangeRate and getCountries over to async functions. They're good candidates because we do have promises and we could just await those promises instead. Then we're going to talk about errors, how we can throw them and how we can customize errors that get thrown by other code. It's going to make it really useful and it'll make it a lot easier to actually use async/await in the real world where you do need to handle errors.

Converting getExchangeRate and getCountries into the async function

So the first thing we're going to do is convert getExchangeRate and getCountries. The first step I'm going to take is to make this an async function, otherwise we can't use await. Then we're going to go ahead and set up a variable, a const response, and we are going to set this equal to await. Then we're going to await the following promise, the one that comes back from axios.get. I'm going to copy it...