Book Image

Accelerating Server-Side Development with Fastify

By : Manuel Spigolon, Maksim Sinik, Matteo Collina
5 (1)
Book Image

Accelerating Server-Side Development with Fastify

5 (1)
By: Manuel Spigolon, Maksim Sinik, Matteo Collina

Overview of this book

This book is a complete guide to server-side app development in Fastify, written by the core contributors of this highly performant plugin-based web framework. Throughout the book, you’ll discover how it fosters code reuse, thereby improving your time to market. Starting with an introduction to Fastify’s fundamental concepts, this guide will lead you through the development of a real-world project while providing in-depth explanations of advanced topics to prepare you to build highly maintainable and scalable backend applications. The book offers comprehensive guidance on how to design, develop, and deploy RESTful applications, including detailed instructions for building reusable components that can be leveraged across multiple projects. The book presents guidelines for creating efficient, reliable, and easy-to-maintain real-world applications. It also offers practical advice on best practices, design patterns, and how to avoid common pitfalls encountered by developers while building backend applications. By following these guidelines and recommendations, you’ll be able to confidently design, implement, deploy, and maintain an application written in Fastify, and develop plugins and APIs to contribute to the Fastify and open source communities.
Table of Contents (21 chapters)
Part 1:Fastify Basics
Part 2:Build a Real-World Project
Part 3:Advanced Topics

Managing GQL errors

The GraphQL specification defines the error’s format. We have seen an example of it in the Implementing our first GQL query resolver section. The common properties are:

  • message: A message description
  • locations: The GraphQL request document’s coordinates that triggered the error
  • path: The response field that encountered the error
  • extensions: Optional field to include custom output properties

With Mercurius, we can customize the message error by throwing or returning an Error object:

  const resolvers = {
    Query: {
      family: async function familyFunc (parent, args,
      context, info) {
        const familyData =
          await context.familyDL.load(
        if (!familyData) {