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)

Starting a new service with DI

Throughout this book, we have applied DI to an existing service. While this is by far the most common situation we will find ourselves in, sometimes we will have the honor of starting a new project from scratch.

So, what could we do differently?

The user experience

The first thing we should always do is stop and think about the problem we are trying to solve. Go back to the UX discovery survey (Chapter 3, Coding for User Experience). Ask yourselves the following:

  • Who are our users?
  • What do our users want to achieve?
  • What are our users capable of?
  • How do our users expect to use the system we are going to create?

Imagine that you were starting the ACME registration service, how would you answer...