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)

Single responsibility principle (SRP)

"A class should have one, and only one, reason to change."
                                                                                     –Robert C. Martin

Go doesn't have classes, but if we squint a little and replace the word class with objects (structs, functions, interfaces or packages), then the concept still applies.

Why do we want our objects to do only one thing? Let's look at a couple of objects that do one thing:

These objects are simple and easy to use, and have a wide range of uses.

Designing objects so that they all do only one thing sounds okay in the abstract....