Book Image

Agile Technical Practices Distilled

By : Pedro M. Santos, Marco Consolaro, Alessandro Di Gioia
Book Image

Agile Technical Practices Distilled

By: Pedro M. Santos, Marco Consolaro, Alessandro Di Gioia

Overview of this book

The number of popular technical practices has grown exponentially in the last few years. Learning the common fundamental software development practices can help you become a better programmer. This book uses the term Agile as a wide umbrella and covers Agile principles and practices, as well as most methodologies associated with it. You’ll begin by discovering how driver-navigator, chess clock, and other techniques used in the pair programming approach introduce discipline while writing code. You’ll then learn to safely change the design of your code using refactoring. While learning these techniques, you’ll also explore various best practices to write efficient tests. The concluding chapters of the book delve deep into the SOLID principles - the five design principles that you can use to make your software more understandable, flexible and maintainable. By the end of the book, you will have discovered new ideas for improving your software design skills, the relationship within your team, and the way your business works.
Table of Contents (31 chapters)
Free Chapter
Section 1
Section 2
Section 3
Section 4
Chapter 21
License: CyberDojo

Breaking Dependencies Using a Seam

Sometimes it is not possible to write tests due to excessive coupling. If your code is dealing with external dependencies, we can break the dependency to allow the Subject Under Test to be exercised independently.

If the dependency is injected through the constructor or setters, replacing the dependency with a test double should be enough. Unfortunately, that’s not always the case. Sometimes you have to deal with static dependencies or locally generated ones. In those cases, you will have to segregate the dependency, introducing a seam in your code (as specified in Working Effectively with Legacy Code by Michael C. Feathers).

In clothing, a seam joins parts together to form a piece of clothing. In code, we can use this concept to find soft points where we can separate coupled parts. If your language supports passing functions as parameters, you can use the Peel-and-Slice technique by Llewellyn Falco.

We should be extremely careful...