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)

Just-in-Time Dependency Injection

With traditional dependency injection (DI) methods, the parent or calling object supplies the dependencies to the child class. However, there are many cases where the dependencies have a single implementation. In these cases, a pragmatic approach would be to ask yourself, why inject the dependency at all? In this chapter, we will examine just-in-time (JIT) dependency injection, a strategy that gives us many of the benefits of DI, like decoupling and testability, without adding parameters to our constructors or methods.

The following topics will be covered in this chapter:

  • JIT injection
  • Advantages of JIT injection
  • Applying JIT injection
  • Disadvantages of JIT injection