FLACOCO: Fault Localization for Java based on Industry-grade Coverage

TL;DR

FLACOCO is a Java fault localization tool leveraging industry-grade code coverage, demonstrating effectiveness comparable to state-of-the-art tools and supporting industry adoption through reliable coverage analysis.

Contribution

It introduces FLACOCO, a fault localization tool built on JaCoCo, integrating industry-grade coverage for improved accuracy and usability in Java debugging.

Findings

Effectively replaces state-of-the-art fault localization libraries.

Supports all Java versions with a user-friendly interface.

Validated on automatic program repair use-cases.

Abstract

Fault localization is an essential step in the debugging process. Spectrum-Based Fault Localization (SBFL) is a popular fault localization family of techniques, utilizing code-coverage to predict suspicious lines of code. In this paper, we present FLACOCO, a new fault localization tool for Java. The key novelty of FLACOCO is that it is built on top of one of the most used and most reliable coverage libraries for Java, JaCoCo. FLACOCO is made available through a well-designed command-line interface and Java API and supports all Java versions. We validate FLACOCO on two use-cases from the automatic program repair domain by reproducing previous scientific experiments. We find it is capable of effectively replacing the state-of-the-art FL library. Overall, we hope that FLACOCO will help research in fault localization as well as industry adoption thanks to being founded on industry-grade code coverage. An introductory video is available at https://youtu.be/RFRyvQuwRYA