Software Testing can take up to half of the resources of the development of new software. Although there has been a lot of work on automating the testing phase, fixing a bug after its presence has been discovered is still a duty of the programmers. Techniques to help the software developers for locating bugs exist though, and they take name of Automated Debugging. However, to our best knowledge, there has been only little attempt in the past to completely automate the actual changing of the software for fixing the bugs. Therefore, in this paper we propose an evolutionary approach to automate the task of fixing bugs. The basic idea is to evolve the programs (e.g., by using Genetic Programming) with a fitness function that is based on how many unit tests they are able to pass. If a formal specification of the buggy software is given, more sophisticated fitness functions can be designed. Moreover, by using the formal specification as an oracle, we can generate as many unit tests as we want. Hence, a co-evolution between programs and unit tests might take place to give even better results. It is important to know that, to fix the bugs in a program with this novel approach, a user needs only to provide either a formal specification or a set of unit tests. No other information is required.

In the past five years there has been a dramatic increase in work on Search Based Software Engineering (SBSE), an approach to software engineering in which search based optimisation algorithms are used to address problems in Software Engineering. SBSE has been applied to problems throughout the Software Engineering lifecycle, from requirements and project planning to maintenance and re-engineering. The approach is attractive because it offers a suite of adaptive automated and semi-automated solutions in situations typified by large complex problem spaces with multiple competing and conflicting objectives. This paper 1 provides a review and classification of literature on SBSE. The paper identifies research trends and relationships between the techniques applied and the applications to which they have been applied and highlights gaps in the literature and avenues for further research.

Software testing can be re-formulated as a search problem, hence search algorithms (e.g., Genetic Algorithms) can be used to tackle it. Most of the research so far has been of empirical nature, in which novel proposed techniques have been validated on software testing benchmarks. However, only little attention has been spent to understand why metaheuristics can be effective in software testing. This insight knowledge could be used to design novel more successful techniques. Recent theoretical work has tried to fill this gap, but it is very complex to carry out. This has limited its scope so far to only small problems. In this paper, we want to get insight knowledge on a difficult software testing problem. We combine together an empirical and theoretical analysis, and we exploit the benefits of both.

Testing and fault localization are very expensive software engineering tasks that have been tried to be automated. Although many successful techniques have been designed, the actual change of the code for fixing the discovered faults is still a human-only task. Even in the ideal case in which automated tools could tell us exactly where the location of a fault is, it is not always trivial how to fix the code. In this paper we analyse the possibility of automating the complex task of fixing faults. We propose to model this task as a search problem, and hence to use for example evolutionary algorithms to solve it. We then discuss the potential of this approach and how its current limits can be addressed in the future. This task is extremely challenging and mainly unexplored in literature. Hence, this paper only covers an initial investigation and gives directions for future work. A research prototype called JAFF and a case study are presented to give first validation of this approach.

Abstract—Previous approaches to search based test data generation tend to focus on coverage, rather than oracle cost. While there may be an aspiration that systems should have models, checkable specifications and/or contract driven development, this sadly remains an aspiration; in many real cases, system behaviour must be checked by a human. This painstaking checking process forms a significant cost, the oracle cost, which previous work on automated test data generation tends to overlook. One simple way to reduce oracle cost consists of reducing the number of tests generated. In this paper we introduce three algorithms which do this without compromising coverage achieved. We present the results of an empirical study of the effectiveness of the three algorithms on five benchmark programs containing non trivial search spaces for branch coverage. The results indicate that it is, indeed, possible to make reductions in the number of test cases produced by search based testing, without loss of coverage.

Automatic Programming (AP) [15] is an ambitious goal that has been greedily sought since the 1950s. During the history of computer science, the term AP has been used for different concepts. Here, with the term AP we define the automation of implementing software given a starting formal specification. In the past, the work about AP was based on transformations (e.g., [11]), in which formal rules were

Most of the software developed in the world follows the object-oriented (OO) paradigm. However, the existing work on evolutionary testing is mainly targeted to procedural languages. All this work can be used with small changes on OO programs, but object orientation introduces new features that are not present in procedural languages. Some important issues are polymorphism and inheritance. In this paper we want to make a contribution to the inheritance field by proposing some approaches that use the information of the class hierarchy for helping test case generators to better guide the search. To the best of our knowledge, no work exists using this information to propose test cases. In this work we define a branch distance for logical expressions containing the instanceof operator in Java programs. In addition to the distance measure, we propose two mutation operators based on the distance. We study the behaviour of the mutation operators on a benchmark set composed of nine OO programs. The results show that the information collected from the class hierarchy helps in the search for test cases.

Search algorithms have been used to tackle software engineering problems with promising results. Although the field has attracted a lot of attention recently, it still lacks a theoretical foundation. It has been empirically shown that search algorithms are successful in some software engineering tasks, but we need to understand why and when they are successful. The long term goal is to get insight of how search algorithms work on software engineering problems, so we can exploit this knowledge to design more efficient algorithms. Runtime Analysis is a type of theoretical investigation that aims to determine, via rigorous mathematical proofs, the time a search algorithm needs to find an optimal solution. Runtime analysis has previously been carried out on traditional combinatorial problems. In this paper, we advocate that runtime analysis would be helpful in search based software engineering as well. We give the first runtime analysis of search heuristics in the software testing domain.