Automated tests are a very useful way of improving code quality. They provide a context for development, documentation, and an on-going check of code correctness. These benefits give you the confidence to build on and refactor code knowing that it will continue to work as designed. This chapter covers the application testing facilities provided by Fabric3. Some familiarity with Ant, Maven, JUnit and mock objects are assumed.
Unit Testing
Java-based components in SCA are in most cases simple POJOs with optional annotations. This means that this guide has little to add to the already well-covered topics of test-driven development and unit testing. It is important to note, however, that even with Fabric3's strong support for integration testing (examined below), it remains easier to find and fix a whole class of bugs by running lightweight tests as opposed to a (slower) test-harness.
Integration Testing
Fabric 3 integration tests ensure that component implementations and composites provide the expected functionality and interact with other services and runtime resources in the expected way. They are referred to as 'itests'.
While Fabric 3 does provide a lightweight standalone runtime environment, the recommended way to drive automated integration tests is through the specialized Maven plug-in or Ant Task. These handle the creation of an embedded Fabric3 runtime, deployment, and test execution. Fast runtime bootstrap and test execution makes iterative development easier. Since the Maven plug-in and Ant Task provide the same execution environment as the standalone server, component behavior verification can be done with little overhead. Use of the Maven plug-in and Ant Task also allows integration tests to be initiated in exactly the same way on development machines and the build server.