Agile Testing: A Practical Guide for Testers and Agile Teams

Like a lot of terminology, “agile development” and “agile testing” mean different things to different people. In this chapter, we explain our view of agile, which reflects the Agile Manifesto and general principles and values shared by different agile methods. We want to share a common language with you, the reader, so we’ll go over some of our vocabulary. We compare and contrast agile development and testing with the more traditional phased approach. The “whole team” approach promoted by agile development is central to our attitude toward quality and testing, so we also talk about that here.

Agile Values

“Agile” is a buzzword that will probably fall out of use someday and make this book seem obsolete. It’s loaded with different meanings that apply in different circumstances. One way to define “agile development” is to look at the Agile Manifesto (see Figure 1-1).

Figure 1-1 Agile Manifesto

Using the values from the Manifesto to guide us, we strive to deliver small chunks of business value in extremely short release cycles.

We use the word “agile” in this book in a broad sense. Whether your team is practicing a particular agile method, such as Scrum, XP, Crystal, DSDM, or FDD, to name a few, or just adopting whatever principles and practices make sense for your situation, you should be able to apply the ideas in this book. If you’re delivering value to the business in a timely manner with high-quality software, and your team continually strives to improve, you’ll find useful information here. At the same time, there are particular agile practices we feel are crucial to any team’s success. We’ll talk about these throughout the book.

Chapter 21, “Key Success Factors,” lists key success factors for agile testing.

What Do We Mean by “Agile Testing”?

You might have noticed that we use the term “tester” to describe a person whose main activities revolve around testing and quality assurance. You’ll also see that we often use the word “programmer” to describe a person whose main activities revolve around writing production code. We don’t intend that these terms sound narrow or insignificant. Programmers do more than turn a specification into a program. We don’t call them “developers,” because everyone involved in delivering software is a developer. Testers do more than perform “testing tasks.” Each agile team member is focused on delivering a high-quality product that provides business value. Agile testers work to ensure that their team delivers the quality their customers need. We use the terms “programmer” and “tester” for convenience.

Several core practices used by agile teams relate to testing. Agile programmers use test-driven development (TDD), also called test-driven design, to write quality production code. With TDD, the programmer writes a test for a tiny bit of functionality, sees it fail, writes the code that makes it pass, and then moves on to the next tiny bit of functionality. Programmers also write code integration tests to make sure the small units of code work together as intended. This essential practice has been adopted by many teams, even those that don’t call themselves “agile,” because it’s just a smart way to think through your software design and prevent defects. Figure 1-2 shows a sample unit test result that a programmer might see.

Figure 1-2 Sample unit test output

This book isn’t about unit-level or component-level testing, but these types of tests are critical to a successful project. Brian Marick [2003] describes these types of tests as “supporting the team,” helping the programmers know what code to write next. Brian also coined the term “technology-facing tests,” tests that fall into the programmer’s domain and are described using programmer terms and jargon. In Part II, we introduce the Agile Testing Quadrants and examine the different categories of agile testing. If you want to learn more about writing unit and component tests, and TDD, the bibliography will steer you to some good resources.