# Practical Constraint Solving for Generating System Test Data

## TL;DR

This paper introduces a novel hybrid approach combining metaheuristic search and SMT solving to generate complex system test data efficiently, improving scalability and applicability over existing methods.

## Contribution

It presents a new method that integrates metaheuristics with SMT solving for constraint-based test data generation in system testing.

## Key findings

- Significant scalability improvements over existing methods.
- Effective handling of complex constraints in industrial case studies.
- Demonstrated applicability to real-world system testing scenarios.

## Abstract

The ability to generate test data is often a necessary prerequisite for automated software testing. For the generated data to be fit for its intended purpose, the data usually has to satisfy various logical constraints. When testing is performed at a system level, these constraints tend to be complex and are typically captured in expressive formalisms based on first-order logic. Motivated by improving the feasibility and scalability of data generation for system testing, we present a novel approach, whereby we employ a combination of metaheuristic search and Satisfiability Modulo Theories (SMT) for constraint solving. Our approach delegates constraint solving tasks to metaheuristic search and SMT in such a way as to take advantage of the complementary strengths of the two techniques. We ground our work on test data models specified in UML, with OCL used as the constraint language. We present tool support and an evaluation of our approach over three industrial case studies. The results indicate that, for complex system test data generation problems, our approach presents substantial benefits over the state of the art in terms of applicability and scalability.