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)

Off-the-Shelf Injection

For our final chapter in this section, we are looking at dependency injection (DI) using a framework. Choosing a DI framework that matches your preferred style can make your life significantly easier. Even if you prefer not to use a framework, examining how it is implemented and the approach it takes can be informative and help you find improvements for your preferred implementation.

While there are many frameworks available to us, including Facebook's Inject ( and Uber's Dig (, for our sample service we are going to use Google's Go Cloud Wire (

The following topics will be covered in this chapter:

  • Off-the-shelf injection with Wire
  • Advantages of off-the-shelf injection
  • Applying off-the-shelf injection
  • Disadvantages...