GAssert: A Fully Automated Tool to Improve Assertion Oracles

TL;DR

GASSERT is an automated tool that enhances assertion oracles in Java programs by reducing false positives and negatives using a novel co-evolutionary algorithm, improving the reliability of program assertions.

Contribution

It introduces GASSERT, the first fully automated tool to improve assertion oracles, employing a co-evolutionary algorithm guided by multiple fitness functions.

Findings

Reduces false positives and negatives in assertions

Automatically improves assertion quality in Java methods

Uses a novel co-evolutionary algorithm for assertion refinement

Abstract

This demo presents the implementation and usage details of GASSERT, the first tool to automatically improve assertion oracles. Assertion oracles are executable boolean expressions placed inside the program that should pass (return true) for all correct executions and fail (return false) for all incorrect executions. Because designing perfect assertion oracles is difficult, assertions are prone to both false positives (the assertion fails but should pass) and false negatives (the assertion passes but should fail). Given a Java method containing an assertion oracle to improve, GASSERT returns an improved assertion with fewer false positives and false negatives than the initial assertion. Internally, GASSERT implements a novel co-evolutionary algorithm that explores the space of possible assertions guided by two fitness functions that reward assertions with fewer false positives, fewer false negatives, and smaller size.