Data Flow Testing of CGI Based Web Applications

The functionality of most programs is delivered in terms of data. The values are somehow received by variables, which represent data and these values are used in computation of values for other variables. Data flow testing focuses on variable definition and variable usage. One of the fastest growing and most wide-spread application domains is the web application domain. The wide acceptance of Internet Technology requires sophisticated and high quality web applications. There are some sorts of entry forms that are provided by many web pages. These web pages require the user to supply input to the forms and click on the button or image. Sometimes, this program (commonly known as CGI program) is just an interface to an existing database, massaging user input into a database understandable format and massaging the database´s output into the web browser understandable format (usually HTML). In this paper, we propose a technique for data flow testing of CGI programs that are written in Perl. We first propose a data flow model and compute definition-use chains. Then, we identify the paths to be exercised for each of these definition-use pairs.