Comparison of Integration Coverage Criteria for Serverless Applications

Serverless computing is a modern computing model which is mainly based on serverless functions. These functions are combined with other serverless functions and services to build applications whose integration has to be tested. Coverage criteria are commonly used to determine the relevance of test cases within a test suite. However, it is unclear how effective these criteria are at detecting faults. To investigate this issue, we designed an experiment in which we injected faults into several applications by using mutation operators. Tests suites fulfilling different coverage criteria were run on these applications and compared to randomly generated test suites and each other. Our results showed that the use of coverage criteria can significantly improve the identification of integration-related faults. Additionally, our research suggests that it is beneficial to apply some coverage criteria in an earlier stage to quickly identify faults, before moving on to more comprehensive criteria. Therefore, by applying coverage criteria, developers can create and select relevant test cases and improve the quality of the serverless applications built.