Agile Testing: A Practical Guide for Testers and Agile Teams

Like the Quadrant 1 tests, they also drive development, but at a higher level. With agile development, these tests are derived from examples provided by the customer team. They describe the details of each story. Business-facing tests run at a functional level, each one verifying a business satisfaction condition. They’re written in a way business experts can easily understand using the business domain language. In fact, the business experts use these tests to define the external quality of the product and usually help to write them. It’s possible this quadrant could duplicate some of the tests that were done at the unit level; however, the Quadrant 2 tests are oriented toward illustrating and confirming desired system behavior at a higher level.

Chapter 8, “Business-Facing Tests that Support the Team,” explains business conditions of satisfaction.

Most of the business-facing tests that support the development team also need to be automated. One of the most important purposes of tests in these two quadrants is to provide information quickly and enable fast troubleshooting. They must be run frequently in order to give the team early feedback in case any behavior changes unexpectedly. When possible, these automated tests run directly on the business logic in the production code without having to go through a presentation layer. Still, some automated tests must verify the user interfaces and any APIs that client applications might use. All of these tests should be run as part of an automated continuous integration, build, and test process.

There is another group of tests that belongs in this quadrant as well. User interaction experts use mock-ups and wireframes to help validate proposed GUI (graphical user interface) designs with customers and to communicate those designs to the developers before they start to code them. The tests in this group are tests that help support the team to get the product built right but are not automated. As we’ll see in the following chapters, the quadrants help us identify all of the different types of tests we need to use in order to help drive coding.

Some people use the term “acceptance tests” to describe Quadrant 2 tests, but we believe that acceptance tests encompass a broader range of tests that include Quadrants 3 and 4. Acceptance tests verify that all aspects of the system, including qualities such as usability and performance, meet customer requirements.

Using Tests to Support the Team

The quick feedback provided by Quadrants 1 and 2 automated tests, which run with every code change or addition, form the foundation of an agile team. These tests first guide development of functionality, and when automated, then provide a safety net to prevent refactoring and the introduction of new code from causing unexpected results.

Lisa’s Story

We run our automated tests that support the team (the left half of the quadrants) in separate build processes. Unit and component tests run in our “ongoing” build, which takes about eight minutes to finish. Although the programmers run the unit tests before they check in, the build might still fail due to integration problems or environmental differences. As soon as we see the “build failed” email, the person who checked in the offending code fixes the problem. Business-facing functional tests run in our “full build,” which also runs continually, kicking off every time a code change is checked in. It finishes in less than two hours. That’s still pretty quick feedback, and again, a build failure means immediate action to fix the problem. With these builds as a safety net, our code is stable enough to release every day of the iteration if we so choose.

—Lisa

The tests in Quadrants 1 and 2 are written to help the team deliver the business value requested by the customers. They verify that the business logic and the user interfaces behave according to the examples provided by the customers. There are other aspects to software quality, some of which the customers don’t think about without help from the technical team. Is the product competitive? Is the user interface as intuitive as it needs to be? Is the application secure? Are the users happy with how the user interface works? We need different tests to answer these types of questions.

Tests that Critique the Product

If you’ve been in a customer role and had to express your requirements for a software feature, you know how hard it can be to know exactly what you want until you see it. Even if you’re confident about how the feature should work, it can be hard to describe it so that programmers fully understand it.