Book Image

Hands-On Dependency Injection in Go

By : Corey Scott
Book Image

Hands-On Dependency Injection in Go

By: Corey Scott

Overview of this book

Hands-On Dependency Injection in Go takes you on a journey, teaching you about refactoring existing code to adopt dependency injection (DI) using various methods available in Go. Of the six methods introduced in this book, some are conventional, such as constructor or method injection, and some unconventional, such as just-in-time or config injection. Each method is explained in detail, focusing on their strengths and weaknesses, and is followed with a step-by-step example of how to apply it. With plenty of examples, you will learn how to leverage DI to transform code into something simple and flexible. You will also discover how to generate and leverage the dependency graph to spot and eliminate issues. Throughout the book, you will learn to leverage DI in combination with test stubs and mocks to test otherwise tricky or impossible scenarios. Hands-On Dependency Injection in Go takes a pragmatic approach and focuses heavily on the code, user experience, and how to achieve long-term benefits through incremental changes. By the end of this book, you will have produced clean code that’s easy to test.
Table of Contents (15 chapters)

Introduction to our system

Welcome to the project! So what do you need to know to join the team? As with any project, the first thing you want to know is what it does, its users, and the business environment in which it is deployed.

The system we are working on is an HTTP-based event registration service. It is designed to be called by our web application or native mobile applications. The following diagram shows how it fits into our network:

Currently, there are three endpoints, listed as follows:

  • Register: This will create a new registration record
  • Get: This will return the full details of an existing registration record
  • List: This will return a list of all the registrations

All request and response payloads are in JSON. The data is stored in a MySQL database.

We also have an upstream currency conversion service—which we call during registration—to...