A Technique for Mutation of Java Objects

Mutation analysis inserts faults into a program to create test sets that distinguish the mutant from the original program. Inserted faults must represent plausible errors. Standard transformations can mutate scalar values such as integers, floats, and character data. Mutating objects is an open problem, because object semantics are defined by the programmer and can vary widely. We develop mutation operators and support tools that can mutate Java library items that are heavily used in commercial software. Our mutation engine can support reusable libraries of mutation components to inject faults into objects that instantiate items from these common Java libraries. Our technique should be effective for evaluating real-world software testing suites.