Abstract As we move toward developing object‐oriented (OO) programs, the complexity traditionally found in functions and procedures is moving to the connections among components. Different faults occur when components are integrated to form higher‐level structures that aggregate the behavior and state. Consequently, we need to place more effort on testing the connections among components. Although OO technologies provide abstraction mechanisms for building components that can then be integrated to form applications, it also adds new compositional relations that can contain faults. This paper describes techniques for analyzing and testing the polymorphic relationships that occur in OO software. The techniques adapt traditional data flow coverage criteria to consider definitions and uses among state variables of classes, particularly in the presence of inheritance, dynamic binding, and polymorphic overriding of state variables and methods. The application of these techniques can result in an increased ability to find faults and to create an overall higher quality software. Copyright © 2010 John Wiley & Sons, Ltd.

Contemporary programmers have a predominately visual experience. Computer code is read from sophisticated text editors, analyzed using visual tools, designed using UML, and debugged using a watch window. Little research has attempted to create tools for the non-sighted programmer, using either haptic or aural feedback. In this paper, we present WAD, the wicked audio debugger, a new debugger for Microsoft Visual Studio 2005 that sonifies computer code as an aid to the programmer. This paper has two primary contributions, namely the tool itself and the results of a feasibility study. We conducted this feasibility study to test participants' ability to comprehend dynamic program behavior, including tracking the value of state variables and control flow. Results of our feasibility study show that participants were able to comprehend approximately 86% of dynamic program behavior using audio only.

We present a candidate fault model for pointcuts in AspectJ programs. The fault model identifies faults that we believe are likely to occur when writing pointcuts in the AspectJ language. Categories of fault types are identified, and each individual fault type is described as categorized. We argue that a fault model that focuses on the unique constructs of the AspectJ language is needed for the systematic and effective testing of AspectJ programs. Our pointcut fault model is a first step towards such a model

Layered program auralization uses music for debugging computer code. Layers of musical structure represent the state and behavior of a computer program while it is running, taking advantage of metaphorical relationships between musical structure and programming constructs. This paper makes three contributions to the debugging and program auralization literature. We use cadences, recognizable patterns of chords that usually dictate an ending, to metaphorically represent nesting depth and hierarchical control structures. Auralizations, in our system, use more than one perceptual mapping at a time. Further, we decompose our auralizations into units, which we call layers. This decomposition is similar to using classes in object oriented programming. We see debugging as a time consuming, difficult task, and present a solution where music is played to the programmer during program execution. Our goal is to increase debugging effectiveness and to improve a programmer's comprehension of the runtime behavior of computer programs

Access control features are often spread across and tangled with other functionality in a design. This makes modifying and replacing these features in a design difficult. Aspect-oriented modeling (AOM) techniques can be used to support separation of access control concerns from other application design concerns. Using an AOM approach, access control features are described by aspect models and other application features are described by a primary model. Composition of aspect and primary models yields a design model in which access control features are integrated with other application features. In this paper, we present, through an example, an AOM approach that supports verifiable composition of behaviors described in access control aspect models and primary models. Given an aspect model, a primary model, and a specified property, the composition technique produces proof obligations as the behavioral descriptions in the aspect and primary models are composed. One has to discharge the proof obligations to establish that the composed model has the specified property.

Although program faults are widely studied, there are many aspects of faults that we still do not understand, particularly about OO software. In addition to the simple fact that one important goal during testing is to cause failures and thereby detect faults, a full understanding of the characteristics of faults is crucial to several research areas. The power that inheritance and polymorphism brings to the expressiveness of programming languages also brings a number of new anomalies and fault types. In prior work we presented a fault model for the appearance and realization of OO faults that are specific to the use of inheritance and polymorphism. Many of these faults cannot appear unless certain syntactic patterns are used. The patterns are based on language constructs, such as overriding methods that directly define inherited state variables and non-inherited methods that call inherited methods. If one of these syntactic patterns is used, then we say the software contains an anomaly and possibly a fault. We describe the syntactic patterns for each OO fault type. These syntactic patterns can potentially be found with an automatic tool. Thus, faults can be uncovered and removed early in development.

Fault insertion based techniques have been used for measuring test adequacy and testability of programs. Mutation analysis inserts faults into a program with the goal of creating mutation-adequate test sets that distinguish the mutant from the original program. Software testability is measured by calculating the probability that a program will fail on the next test input coming from a predefined input distribution, given that the software includes a fault. Inserted faults must represent plausible errors. It is relatively easy to apply standard transformations to mutate scalar values such as integers, floats, and character data, because their semantics are well understood. Mutating objects that are instances of user defined types is more difficult. There is no obvious way to modify such objects in a manner consistent with realistic faults, without writing custom mutation methods for each object class. We propose a new object mutation approach along with a set of mutation operators and support tools for inserting faults into objects that instantiate items from common Java libraries heavily used in commercial software as well as user defined classes. Preliminary evaluation of our technique shows that it should be effective for evaluating real-world software testing suites.

Object-oriented programs cause a shift in focus from software units to the way software classes and 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, which can be covered using testing criteria that take the effects of inheritance and polymorphism into account. This paper demonstrates, via a set of experiments, the relative effectiveness of several coupling-based OO testing criteria and branch coverage. OO criteria are all more effective at detecting faults due to the use of inheritance and polymorphism than branch coverage.

Although program faults are widely studied, there are many aspects of faults that we still do not understand, particularly about OO software. In addition to the simple fact that one important goal during testing is to cause failures and thereby detect faults, a full understanding of the characteristics of faults is crucial to several research areas. The power that inheritance and polymorphism brings to the expressiveness of programming languages also brings a number of new anomalies and fault types. This paper presents a model for the appearance and realization of OO faults and defines and discusses specific categories of inheritance and polymorphic faults. The model and categories can be used to support empirical investigations of object-oriented testing techniques, to inspire further research into object-oriented testing and analysis, and to help improve design and development of object-oriented software.

Mutation analysis inserts faults into a program to create test sets that distinguish the mutant from the original program. Inserted faults must represent plausible errors. Standard transformations can mutate scalar values such as integers, floats, and character data. Mutating objects is an open problem, because object semantics are defined by the programmer and can vary widely. We develop mutation operators and support tools that can mutate Java library items that are heavily used in commercial software. Our mutation engine can support reusable libraries of mutation components to inject faults into objects that instantiate items from these common Java libraries. Our technique should be effective for evaluating real-world software testing suites.

This research is part of a project to develop practical, effective, formalizable, automatable techniques for integration testing. Integration testing is an important part of the testing process, but few integration testing techniques have been systematically studied or defined. This paper discusses the design and implementation of an analysis tool for measuring the amount of coverage achieved by a set of test data according to a set of previously defined coupling criteria. This tool can be used to support integration testing of software components. The coupling-based testing technique, which has been described elsewhere, is summarized, and coverage algorithms are discussed. The focus of this paper is on the instrumentation techniques and an analysis tool built for Java programs. It was built in Java using the general Java parser JavaCC and the Java Tree Builder (JTB). We are currently using this tool to gather experimental data on the efficacy and the usefulness of the technique.

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. The 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 quasi-interprocedural data flow analysis. These testing criteria can improve the quality of object oriented software by ensuring that integration tests are high quality.