Java Power Tools

Chapter 11. Next-Generation Testing with TestNG

Introducing TestNG

TestNG is an innovative unit test framework, written by Cédric Beust and Alexandru Popescu, designed to overcome many of the perceived shortcomings of JUnit 3 (see JUnit 3.8 and JUnit 4). Like JUnit 4, TestNG improves on JUnit 3 in many ways, removing syntactical constraints and adding flexible, nonintrusive annotation-based testing. In addition, TestNG also supports many powerful features such as test groups, dependencies, and parallel testing—features that are not yet supported by JUnit 4 at the time of this writing. TestNG integrates well with IDEs such as Eclipse and build tools like Ant and Maven. All of these features make it easier to write better-designed, faster and more flexible unit tests.

Creating Simple Unit Tests with TestNG

Before discussing the more advanced features of TestNG, we will take a quick introductory tour. Let’s look at how to get started with TestNG.

TestNG classes are ordinary Java classes with ordinary methods: They don’t have to extend a particular class, nor do their methods have to follow any particular naming convention. You simply use the @Test annotation to flag unit test methods, and use Java 5 asserts to test calculated values against expected ones. Throughout this chapter, we will use the example of a class that calculates GST (goods and services tax, also known as a value added tax in some countries), which we introduced in JUnit 3.8 and JUnit 4. This class is supposed to calculate ...