There is a lack of automatic evaluation models to measure the user experience (UX) of online systems, especially in relation to the user interaction. In this paper we propose the interaction effort score as a factor that contributes to the measure of the UX of a web page. The interaction effort is automatically computed as an aggregation of the effort on each interactive widget of a page, and for all users that have interacted with them.\nIn turn, the effort on each widget is predicted from different micro-measures computed on the user interaction, by learning from manual UX expert ratings. This paper describes the evaluation of the interaction effort of different web forms, and how it compares to other metrics of usability and user interaction. It also shows possible applications of the interaction effort score in the automatic evaluation of web pages.

Software testing is an integral and important part of the software engineering discipline, and its automation has been actively pursued in both academia and industry to reduce its high costs. In the past decades, a considerable research effort has been devoted to automatic test case generation, automatic test selection, and automatic test oracles. The practice of software test automation has also moved forward significantly, and in recent years, a large number of software test tools have been developed and released to the market. However, progress in automatic software testing (AST) research is still required. The increasing complexity, pervasiveness and inter-connection of software systems, the ever-shrinking development cycles and time-to-market, and the scarcity of tools that can support all testing tasks within one environment, have posed new challenges and stricter constraints. Thus, despite significant achievements both in theory and practice, AST remains a challenging research area, and there is an urgent requirement to improve test automation to scale up productivity and quality in software development. Many times, however, industry needs differ from the research agenda, as companies need to prioritize reducing cost and time-to-market. Moreover, practitioners may have a hard time choosing a particular testing method or technology, since the real challenges that influence the decision are usually hidden.\nThis special issue includes revised and extended versions of the best papers presented at the 2nd ACM/IEEE International Conference on Automation of Software Test (AST 2021), held in conjunction with the 43rd International Conference on Software Engineering (ICSE 2021), as well as new original submissions on the theme of “Automatic Software Testing from the Trenches.” This issue initially received a total of 13 submissions.\nBoth the extended papers from AST 2021 as well as the new original submissions underwent a rigorous review process, and ultimately, 8 submissions were accepted for inclusion in this special issue.

One of the key benefits of blockchain technology is its ability to keep a permanent, unalterable record of transactions. In business environments, where companies interact with each other without a centralized authority to ensure trust between them, this has led to blockchain platforms and smart contracts being proposed as a means of implementing trustworthy collaborative processes. Software engineers must deal with them to ensure the quality of smart contracts in all phases of the smart contract lifecycle, from requirements specifications to design and deployment. This broad scope and criticality of smart contracts in business environments means that they have to be expressed in a language that is intuitive, easy-to-use, independent of the blockchain platform employed, and oriented towards software quality assurance. In this paper we present a key component: a first outline of a UML-based smart contract meta-model that would allow us to achieve these objectives. This meta-model will be enriched in future work to represent blockchain environments and automated testing.

Usability and user interaction improvement is a central task in web development to guarantee the success of a web application. However, designers are barely able to keep up with the current development cycle because their practices are too costly, while interaction issues accumulate in applications that end-users keep suffering. In this work, we propose a method for designers to rapidly explore solutions through visual programming to the interaction problems of an application under development, even when it has been already deployed. The method is realized by a tool called UX-Painter, an exploratory tool for designers to apply quick fixes to interaction issues at the client-side of a web application without the need of any script programming knowledge. The palette of available fixes in UX-Painter are client-side web refactorings, i.e., changes to web page elements that solve specific user interaction problems without changing the underlying functionality. UX-Painter allows designers to quickly set up new versions of a web application by combining refactorings to create alternative designs for user testing or an inspection review. UX-Painter also provides the means to communicate design improvements, as a sequence of refactorings with clear semantics. We show the feedback provided by interviews with designers about UX-Painter's functionality and the results of a user test about its usability.

Client-Side Web Refactorings (CSWRs) allow improving interaction aspects of web applications by applying changes to the user interface without altering the code base, even in production settings. However, developers are not always willing, or even allowed to apply external adaptations to their applications’ user interface. Besides, CSWRs do not guarantee improvements in all contexts, so it may be unwise to install them in a production version. We propose a tool that allows creating private versions of a running web application almost automatically. Using this tool, developers or usability experts can easily combine CSWRs to create alternative versions of web applications, without the need of creating a cloned sandbox environment for each version. This yields many uses, such as quickly setting up user tests, showing live alternatives to Product Owners, and even performing A/B testing. The tool is built on top of Kobold, a service that allows applying CSWRs to fix usability smells. Kobold with versioning is available at: https://autorefactoring.lifia.info.unlp.edu.ar. A screencast of the tool is available at https://youtu.be/LVc3BOtVP3I.

While Web applications have become pervasive in today's business, social interaction and information exchange, their usability is often deficient, even being a key factor for a website success. Usability problems repeat across websites, and many of them have been catalogued, but usability evaluation and repair still remains expensive. There are efforts from both the academy and industry to automate usability testing or to provide automatic statistics, but they rarely offer concrete solutions. These solutions appear as guidelines or patterns that developers can follow manually. This paper presents Kobold, a tool that detects usability problems from real user interaction (UI) events and repairs them automatically when possible, at least suggesting concrete solutions. By using the refactoring technique and its associated concept of bad smell, Kobold mines UI events to detect usability smells and applies usability refactorings on the client to correct them. The purpose of Kobold is to deliver usability advice and solutions as a service (SaaS) for developers, allowing them to respond to feedback of the real use of their applications and improve usability incrementally, even when there are no usability experts on the team. Kobold is available at: http://autorefactoring.lifia.info.unlp.edu.ar. A screencast is available at https://youtu.be/c-myYPMUh0Q.

ABSTRACT C preprocessor directives are heavily used in C programs because they provide useful and even necessary additions to the C language. However, they are usually executed and discarded before any analysis is applied on C programs. In refactoring, preprocessor directives must be preserved through the whole process of parsing, analysis and transformation to retain editable yet correct source code. We propose a new preprocessing approach and special program representations that allow a program to be analyzed and transformed without losing its preprocessor directives, but treating them as first‐class program entities. These representations are essential for a correct refactoring tool. We also describe the challenges that preprocessor directives bring to refactoring and how the program representations that we propose solve those challenges. Finally, we give details of two refactorings and present some case studies with our successfully applied solution. Copyright © 2013 John Wiley & Sons, Ltd.

Rich Internet applications (RIAs) combine the simplicity of the hypertext paradigm with the flexibility of desktop interfaces. The quick emergence of these applications is driving a new (r)evolution in the Webfield. Building RIAs from scratch is often unfeasible because companies do not want to loose their investments in legacy Web software; additionally, most users are still accustomed to the "old" Web interaction style. In this paper we present an evolutionary approach to transform conventional Web software into RIAs; we show how to apply the well known refactoring concept to seamless introduce rich interface functionality in a Web application. By applying refactoring at the model level, we make the transition more systematic and less prone to error. We briefly introduce the problem with a simple example, and then we describe two refactorings and present our approach to specify these refactorings at the interface design level.

Preprocessor conditionals are heavily used in C programs since they allow the source code to be configured for different platforms or capabilities. However, preprocessor conditionals, as well as other preprocessor directives, are not part of the C language. They need to be evaluated and removed, and so a single configuration selected, before parsing can take place. Most analysis and program understanding tools run on this preprocessed version of the code so their results are based on a single configuration. This paper describes the approach of CRefactory, a refactoring tool for C programs. A refactoring tool cannot consider only a single configuration: changing the code for one configuration may break the rest of the code. CRefactory analyses the program for all possible configurations simultaneously. CRefactory also preserves preprocessor directives and integrates them in the internal representations. The paper also presents metrics from two case studies to show that CRefactory's program representation is practical.

Refactoring, an important technique for increasing flexibility of the source code, can be applied with much ease and efficiency by using automated tools. There is currently a lack of refactoring tools for C with full support for preprocessor directives because directives complicate refactorings in many ways. This paper describes refactoring of C programs in the presence of conditional compilation directives and how we propose to support them in a refactoring tool.