BTestBox: A Tool for Testing B Translators and Coverage of B Models

The argument of correctness in refinement-based formal software design often disregards source code analysis and code generation. To mitigate the risk of errors in these phases, certifications issued by regulation entities demand or recommend testing the generated software using a code coverage criteria. We propose improvements for the BTestBox, a tool for automatic generation of tests for software components developed with the B method. BTestBox supports several code coverage criteria and code generators for different languages. The tool uses a constraint solver to produce tests, thus being able to identify dead code and tautological branching conditions. It also generates reports with different metrics and may be used as an extension to the Atelier B. Our tool performs a double task: first, it acts on the B model, by checking the code coverage. Second, the tool performs the translation of lower level B specifications into programming language code, runs tests and compares their results with the expected output of the test cases. The present version of BTestBox uses parallelisation techniques that significantly improve its performance. The results presented here are encouraging, showing performance numbers that are one order of magnitude better than the ones obtained in the tool’s previous version.