ReSuMo: a regression strategy and tool for mutation testing of solidity smart contracts

Mutation testing is a powerful test adequacy assessment tech- nique that can guarantee the deployment of deeply scrutinized and more reliable Smart Contract code. However, regularly evaluating the test suite during the evolution of a project can be unfeasible due to the high costs of the assessment. This paper presents ReSuMo, the first regression mutation testing approach and tool for Solidity Smart Contracts. ReSuMo uses a static and file-level technique to select a subset of Smart Contracts to mutate, and a subset of test files to re-run during a regression mutation test- ing campaign. After a mutation testing run, ReSuMo incrementally updates the results using the test outcomes of the mutation cam- paign registered on the previous program revision. In this way, it can speed up the mutation testing process for evolving projects, while providing a comprehensive adequacy assessment of the whole test suite.