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
1
Section 1
7
Section 2
13
Section 3
19
Section 4
25
Chapter 21
28
License: CyberDojo

Characterization Tests

Michael C. Feathers, who coined the term characterization test, defines it as a test that describes (characterizes) the actual behavior of a piece of code. These tests protect the existing behavior of legacy code against unintended changes via automated testing.

In other words, they don’t check what the code is supposed to do like specification tests do, but what the code actually and currently does. Having a set of characterization tests helps developers working with legacy code because they can run these tests after modifying their code, ensuring that their modification did not cause any unintended or unwanted changes in functionality somewhere else.

  1. Use a piece of code in a test harness.
  2. Write an assertion that you know will fail.
  3. Run the test and let the failure tell you what the actual behavior is.
  4. Change the test so that it expects the behavior that the code actually produces.
  5. Repeat until you are reasonably sure all the...