ExLi: An Inline-Test Generation Tool for Java

Abstract

We present ExLi, a tool for automatically generating inline tests, which were recently proposed for statement-level code validation. ExLi is the first tool to support retrofitting inline tests to existing codebases, towards increasing adoption of this type of tests. ExLi first extracts inline tests from unit tests that validate methods that enclose the target statement under test. Then, ExLi uses acoverage-then-mutants based approach to minimize the set of initially generated inline tests, while preserving their fault-detection capability. ExLi works for Java, and we use it to generate inlinetests for 645 target statements in 31 open-source projects. ExLi reduces the initially generated 27,415 inline tests to 873. ExLi improves the fault-detection capability of unit test suites from which inline tests are generated: the final set of inline tests kills up to 24.4% more mutants on target statements than developer written and automatically generated unit tests. ExLi is open sourced at https://github.com/EngineeringSoftware/exli and a video demo is available at https://youtu.be/qaEB4qDeds4.