Orthogonal exploration of the search space in evolutionary test case generation

  • Authors:
  • Fitsum M. Kifetew;Annibale Panichella;Andrea De Lucia;Rocco Oliveto;Paolo Tonella

  • Affiliations:
  • Fondazione Bruno Kessler, Italy;University of Salerno, Italy;University of Salerno, Italy;University of Molise, Italy;Fondazione Bruno Kessler, Italy

  • Venue:
  • Proceedings of the 2013 International Symposium on Software Testing and Analysis
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

The effectiveness of evolutionary test case generation based on Genetic Algorithms (GAs) can be seriously impacted by genetic drift, a phenomenon that inhibits the ability of such algorithms to effectively diversify the search and look for alternative potential solutions. In such cases, the search becomes dominated by a small set of similar individuals that lead GAs to converge to a sub-optimal solution and to stagnate, without reaching the desired objective. This problem is particularly common for hard-to-cover program branches, associated with an extremely large solution space. In this paper, we propose an approach to solve this problem by integrating a mechanism for orthogonal exploration of the search space into standard GA. The diversity in the population is enriched by adding individuals in orthogonal directions, hence providing a more effective exploration of the solution space. To the best of our knowledge, no prior work has addressed explicitly the issue of evolution direction based diversification in the context of evolutionary testing. Results achieved on 17 Java classes indicate that the proposed enhancements make GA much more effective and efficient in automating the testing process. In particular, effectiveness (coverage) was significantly improved in 47% of the subjects and efficiency (search budget consumed) was improved in 85% of the subjects on which effectiveness remains the same.