Test automation mostly using unit testing is a key feature of extreme programming and agile software development, where it is known as test-driven development (TDD) or test-first development. Unit tests can be written to define the functionality before the code is written. However, these unit tests evolve and are extended as coding progresses, issues are discovered and the code is subjected to refactoring. Only when all the tests for all the demanded features pass is the code considered complete. Proponents argue that it produces software that is both more reliable and less costly than code that is tested by manual exploration. It is considered more reliable because the code coverage is better, and because it is run constantly during development rather than once at the end of a waterfall development cycle. The developer discovers defects immediately upon making a change, when it is least expensive to fix. Finally, code refactoring is safer when unit testing is used; transforming the code into a simpler form with less code duplication, but equivalent behavior, is much less likely to introduce new defects when the refactored code is covered by unit tests.
Software tests have to be repeated often during development cycles to ensure quality. Every time source code is modified software tests should be repeated. For each release of the software it may be tested on all supported operating systems and hardware configurations. Manually repeating these tests is costly and time consuming. Once created, automated tests can be run over and over again at no additional cost and they are much faster than manual tests. Automated software testing can reduce the time to run repetitive tests from days to hours. A time savings that translates directly into cost savings.
One way to generate test cases automatically is model-based testing through use of a model of the system for test case generation, but research continues into a variety of alternative methodologies for doing so. In some cases, the model-based approach enables non-technical users to create automated business test cases in plain English so that no programming of any kind is needed in order to configure them for multiple operating systems, browsers, and smart devices.
Robust GUI test automation begins with the reliable object identification provided by Ranorex Spy. This tool can be used alone or from within the Ranorex Studio environment to deliver industry-leading recognition of GUI objects and controls, and ensure that each user interface element is uniquely identified using the powerful RanoreXPath syntax. Information on identified objects can be shared with team members through snapshot files, or stored in the Ranorex object repository for use in automated tests. The object repository in Ranorex Studio manages identified UI objects, so that they are editable and re-usable across testing projects. Features of the repository include the ability to assign meaningful names to repository objects to make them more maintainable, set default values, or link objects to parameter values. Ranorex Studio tools support best practices in automated test case design, including separation of test data from procedures, use of local and global parameters to pass values, and easily reusable code modules that can be shared by the entire team.