Automatic test data generation for programs with integer and float variables

The paper presents a novel approach for automated test data generation of imperative programs containing integer, boolean and/or float variables. Our approach is based on consistency techniques integrating integer and float variables. We handle statement, branch and path coverage criteria. Our purpose is thus to automatically generate test data that will cause the program to execute a statement, to traverse a branch or to traverse a specified path. For path coverage, the specified path is transformed into a path constraint which is solved by an interval-based constraint solving algorithm handling integer, boolean and real variables. A valid test input is then extracted from the interval solutions. For statement (and branch) coverage, a path reaching the specified statement or branch is dynamically constructed. Our algorithm for path coverage is then applied. The search for a suitable path and the solving of path constraints make extensive use of consistency techniques. We propose a simple consistency notion called eBox consistency, for generalizing box consistency to integer and float variables. The eBox consistency is sufficient for our purpose. A prototype has been developed and experimental results show the feasibility of our approach. This work is an extension of work by A. Gotlieb (2000) for float and boolean variables.