We present and evaluate an automatic tool for extracting algebraic specifications from Java classes. Our tool maps a Java class to an algebraic signature and then uses the signature to generate a large number of terms. The tool evaluates these terms and based on the results of the evaluation, it proposes equations. Finally, the tool generalizes equations to axioms and eliminates many redundant axioms. Since our tool uses dynamic information, it is not guaranteed to be sound or complete. However, we manually inspected the axioms generated in our experiments and found them all to be correct.

Several module and class testing techniques have been applied to object-oriented programs, but researchers have only recently begun developing test criteria that evaluate the use of key OO features such as inheritance, polymorphism, and encapsulation. Mutation testing is a powerful testing technique for generating software tests and evaluating the quality of software. However, the cost of mutation testing has traditionally been so high it cannot be applied without full automated tool support. This paper presents a method to reduce the execution cost of mutation testing for OO programs by using two key technologies, Mutant Schemata Generation (MSG) and bytecode translation. This method adapts the existing MSG method for mutants that change the program behavior and uses bytecode translation for mutants that change the program structure. A key advantage is in performance: only two compilations are required and both the compilation and execution time for each is greatly reduced. A mutation tool based on the MSG/bytecode translation method has been built and used to measure the speedup over the separate compilation approach. Experimental results show that the MSG/bytecode translation method is about five times faster than separate compilation.

The emphasis in object-oriented programs is on defining abstractions that have both state and behavior. This emphasis causes a shift in focus from software units to the way software components are connected. Thus, we are finding that we need less emphasis on unit testing and more on integration testing. The compositional relationships of inheritance and aggregation, especially when combined with polymorphism, introduce new kinds of integration faults. This paper presents results from an ongoing research project that has the goal of improving the quality of object-oriented software. New testing criteria are introduced that take the effects of inheritance and polymorphism into account. These criteria are based on the new analysis technique of quasiinterprocedural data flow analysis. These testing criteria can improve the quality of object-oriented software by ensuring that integration tests are high quality.

Programs developed with object technologies have unique features that often make traditional testing methods inadequate. Consider, for instance, the dependence between the state of an object and the behavior of that object: The outcome of a method executed by an object often depends on the state of the object when the method is invoked. It is therefore crucial that techniques for testing of classes exercise class methods when the method's receiver is in different states. The state of an object at anygiven time depends on the sequence of messages received by the object up to that time. Thus, methods for testing object-oriented software should identify sequences of method invocations that are likely to uncover potential defects in the code under test. However, testing methods for traditional software do not provide this kind of information.

Where the development, understanding, and assessment of software testing and regression testing techniques are concerned, controlled experimentation is an indispensable research methodology. Obtaining the infrastructure necessary to support rigorous controlled experimentation with testing techniques, however, is difficult and expensive. As a result, progress in experimentation with testing techniques has been slow, and empirical data on the costs and effectiveness of testing techniques remains relatively scarce. To help address this problem, we have been designing and constructing infrastructure to support controlled experimentation with software testing and regression testing techniques. This paper reports on the challenges faced by researchers experimenting with testing techniques, including those that inform the design of our infrastructure. The paper then describes the infrastructure that we are creating in response to these challenges, and that we are now making available to other researchers, and discusses the impact that this infrastructure has and can be expected to have on controlled experimentation with testing techniques.

Despite their benefits, programmers rarely use formal specifications, because they are difficult to write and they require an up front investment in time. To address these issues, we present a tool that helps programmers write and debug algebraic specifications. Given an algebraic specification, our tool instantiates a prototype that can be used just like any regular Java class. The tool can also modify an existing application to use the prototype generated by the interpreter instead of a hand-coded implementation. The tool improves the usability of algebraic specifications in the following ways: (i) A programmer can “run ” an algebraic specification to study its behavior. The tool reports in which way a specification is incomplete for a client application. (ii) The tool can check whether a specification and a hand-coded implementation behave the same for a particular run of a client application. (iii) A prototype can be used when a hand-coded implementation is not yet available. Two case studies demonstrate how to use the tool. 1.

WS-BPEL applications are a kind of service-oriented application. They use XPath extensively to integrate loosely-coupled workflow steps. However, XPath may extract wrong data from the XML messages received, resulting in erroneous results in the integrated process. Surprisingly, although XPath plays a key role in workflow integration, inadequate researches have been conducted to address the important issues in software testing. This paper tackles the problem. It also demonstrates a novel transformation strategy to construct artifacts. We use the mathematical definitions of XPath constructs as rewiring rules, and propose a data structure called XPath Rewriting Graph (XRG), which not only models how an XPath is conceptually rewritten but also tracks individual rewritings progressively. We treat the mathematical variables in the applied rewriting rules as if they were program variables, and use them to analyze how information may be rewritten in an XPath conceptually. We thus develop an algorithm to construct XRGs and a novel family of data flow testing criteria to test WS-BPEL applications. Experiment results show that our testing approach is promising.

Abstract — We present a structured reformulation of the seminal algorithm for automatic generation of test cases for a context-free grammar. Our reformulation simplifies the algorithm in several ways. First, we provide a structured reformulation so that it is obvious where to proceed at each step. Second, we partition the intricate third phase into five functions, so that the discussion and comprehension of this phase can be modularized. Our implementation of the algorithm provides information about the grammatic, syntactic and semantic correctness of the generated test cases for two important languages in use today: C and C++. The results of our study of C and C++ highlight a lacuna latent in the research to date. In particular, if one or more of the automatically generated test cases is syntactically or semantically incorrect, then the confidence of structural “coverage ” may be compromised for the particular grammar-based tool under test. Our ongoing work focuses on a solution to this problem. Keywords — Structural-based testing, implementation-based testing, black-box testing, white-box testing, context-free grammar, parsing, re-engineering. I.

The characteristics of object-oriented software affect type and relevance of faults. In particular, the state of the objects may cause faults that cannot be easily revealed with traditional testing techniques. This paper proposes a new technique for interclass testing, that is, the problem of deriving test cases for suitably exercising interactions among clusters of classes. The proposed technique uses data-flow analysis for deriving a suitable set of test case specifications for interclass testing. The paper then shows how to automatically generate feasible test cases that satisfy the derived specifications using symbolic execution and automated deduction. Finally, the paper demonstrates the effectiveness of the proposed technique by deriving test cases for a microscope controller developed for the European Space Laboratory of the Columbus Orbital Facility.

An important activity in software development is the testing of developed software using the appropriate techniques. Obviously, these techniques have to take into account the type of the software process and the type of the developed software. This article proposes a technique for testing classes developed during a special type of software process, namely object-oriented prototyping. Furthermore, the technique developed is suited for application domains requiring a high degree of quality of the deployed software. The main idea of our approach is to interpret each prototyping iteration as a correction of the software, similar to corrections taken during the maintenance phase. With this interpretation in mind, we tried to adopt regression testing techniques for testing prototype classes. Unfortunately, all regression testing techniques we have studied have some shortcomings limiting their applicability to testing prototypes. Therefore, we have developed a new technique that integrates two existing techniques resulting in one which can be used for both white- and black-box testing. Keywords Integrated white- and black-box testing, class-level