Testability transformation: program transformation to improve testability

Testability transformation is a new form of program transformation in which the goal is not to preserve the standard semantics of the program, but to preserve test sets that are adequate with respect to some chosen test adequacy criterion. The goal is to improve the testing process by transforming a program to one that is more amenable to testing while remaining within the same equivalence class of programs defined by the adequacy criterion. The approach to testing and the adequacy criterion are parameters to the overall approach. The transformations required are typically neither more abstract nor are they more concrete than standard "meaning preserving transformations". This leads to interesting theoretical questions. but also has interesting practical implications. This chapter provides an introduction to testability transformation and a brief survey of existing results.