Quality Assurance in PHP Projects

This is an abstract for a chapter from a book on Quality Assurance in PHP Projects.

swoodoo, the Germany-based flight search engine, has gone through a wild evolution. In 2003 it started out as a peer-to-peer network with ActiveX browser plugins written in C++ to query cheap flights. It went through a Java-centric solution using various techniques for screenscraping data from airline websites and finally has evolved into a robust architecture where Java and MySQL are used in the backend and PHP plays a major role in all frontend-related tasks as well as in data gathering from airlines.

Besides technology, the software architecture has also changed immensely: from distributed objects to a "big ball of mud" and finally into a Service-Oriented Architecture (SOA) with clearly defined interfaces between separate services. In order to have a better control of swoodoo evolution, project management was switched to Extreme Programming (XP) in the beginning of 2007. At the same time we introduced unit testing using JUnit and PHPUnit as well as PHP-driven Selenium acceptance testing. Initially we made heavy use of Selenium but recently we have reduced the amount of Selenium tests - a tradeoff we had to make because of the nature of our SOA-based architecture.

In this case study we want to show the evolution of our agile management techniques, testing environment, tools and approaches we use and why we decided to change in case we did.

Lars Jankowfsky is the CTO of Germany-based swoodoo AG.