Extreme Testing

In the 1990s a new software development methodology termed Extreme Programming (XP) was born.

A project manager named Kent Beck is credited with conceiving the lightweight, agile development process, first testing it while working on a project at Daimler-Chrysler in 1996. Although several other agile software development processes have since been created, XP is by far the most popular. In fact, numerous open-source tools exist to support it, which verifies XP’s popularity among developers and project managers.

XP was likely developed to support the adoption of programming languages such as Java, Visual Basic, and C#. These object-based languages

allow developers to create large, complex applications much more quickly than with traditional languages such as C, C++, FORTRAN, or COBOL. Developing with these languages often requires building general-purpose libraries to support your efforts. Methods for common tasks such as printing, sorting, networking, and statistical analysis are not standard components. Languages such as C# and Java ship with full-featured application programming interfaces (APIs) that eliminate or reduce the need for custom library creation.

However, with the benefits of rapid application development languages come liabilities. Although developers were creating applications much more quickly, the quality was not guaranteed. If the application worked, it often failed to meet the program specification.

The purpose of the XP development methodology is to create quality programs in short time frames. Classical software processes still work, but often take too much time, which equates to lost income in the competitive arena of software development.

The XP model relies heavily on unit and acceptance testing of modules. In general, you must run unit tests for every incremental

code change, no matter how small, to ensure that the code base still meets its specification. In fact, testing is of such importance in XP that the process requires that you create the unit (module) and acceptance tests first, then create your code base. This form of testing is called, appropriately, Extreme Testing (XT).