30 Years of Software Refactoring Research: A Systematic Literature Review

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155872/4/30YRefactoring.pd

30 Years of Software Refactoring Research:A Systematic Literature Review

Due to the growing complexity of software systems, there has been a dramatic increase and industry demand for tools and techniques on software refactoring in the last ten years, defined traditionally as a set of program transformations intended to improve the system design while preserving the behavior. Refactoring studies are expanded beyond code-level restructuring to be applied at different levels (architecture, model, requirements, etc.), adopted in many domains beyond the object-oriented paradigm (cloud computing, mobile, web, etc.), used in industrial settings and considered objectives beyond improving the design to include other non-functional requirements (e.g., improve performance, security, etc.). Thus, challenges to be addressed by refactoring work are, nowadays, beyond code transformation to include, but not limited to, scheduling the opportune time to carry refactoring, recommendations of specific refactoring activities, detection of refactoring opportunities, and testing the correctness of applied refactorings. Therefore, the refactoring research efforts are fragmented over several research communities, various domains, and objectives. To structure the field and existing research results, this paper provides a systematic literature review and analyzes the results of 3183 research papers on refactoring covering the last three decades to offer the most scalable and comprehensive literature review of existing refactoring research studies. Based on this survey, we created a taxonomy to classify the existing research, identified research trends, and highlighted gaps in the literature and avenues for further research.Comment: 23 page

Dynamically typed languages

Dynamically typed languages such as Python and Ruby have experienced a rapid grown in popularity in recent times. However, there is much confusion as to what makes these languages interesting relative to statically typed languages, and little knowledge of their rich history. In this chapter I explore the general topic of dynamically typed languages, how they differ from statically typed languages, their history, and their defining features

Engineering Enterprise Software Systems with Interactive UML Models and Aspect-Oriented Middleware

Large scale enterprise software systems are inherently complex and hard to maintain. To deal with this complexity, current mainstream software engineering practices aim at raising the level of abstraction to visual models described in OMG’s UML modeling language. Current UML tools, however, produce static design diagrams for documentation which quickly become out-of-sync with the software, and thus obsolete. To address this issue, current model-driven software development approaches aim at software automation using generators that translate models into code. However, these solutions don’t have a good answer for dealing with legacy source code and the evolution of existing enterprise software systems. This research investigates an alternative solution by making the process of modeling more interactive with a simulator and integrating simulation with the live software system. Such an approach supports model-driven development at a higher-level of abstraction with models without sacrificing the need to drop into a lower-level with code. Additionally, simulation also supports better evolution since the impact of a change to a particular area of existing software can be better understood using simulated “what-if” scenarios. This project proposes such a solution by developing a web-based UML simulator for modeling use cases and sequence diagrams and integrating the simulator with existing applications using aspect-oriented middleware technology

Parsing Fortran-77 with proprietary extensions

Far from the latest innovations in software development, many organizations still rely on old code written in "obsolete" programming languages. Because this source code is old and proven it often contributes significantly to the continuing success of these organizations. Yet to keep the applications relevant and running in an evolving environment, they sometimes need to be updated or migrated to new languages or new platforms. One difficulty of working with these "veteran languages" is being able to parse the source code to build a representation of it. Parsing can also allow modern software development tools and IDEs to offer better support to these veteran languages. We initiated a project between our group and the Framatome company to help migrate old Fortran-77 with proprietary extensions (called Esope) into more modern Fortran. In this paper, we explain how we parsed the Esope language with a combination of island grammar and regular parser to build an abstract syntax tree of the code.Comment: Accepted at ICSME'23 Industrial trac

Model-Based Run-time Verification of Software Components by Integrating OCL into Treaty

Model Driven Development is used to improve software quality and efficiency by automatically transforming abstract and formal models into software implementations. This is particularly sensible if the model’s integrity can be proven formally and is preserved during the model’s transformation. A standard to specify software model integrity is the Object Constraint Language (OCL). Another topic of research is the dynamic development of software components, enabling software system composition at component run-time. As a consequence, the system’s verification must be realized during system run-time (and not during transformation or compile time). Many established verification techniques cannot be used for run-time verification. A method to enable model-based run-time verification will be developed during this work. How OCL constraints can be transformed into executable software artifacts and how they can be used in the component-based system Treaty will be the major task of this diploma thesis.Modellgetriebene Entwicklung dient der Verbesserung von Qualität und Effizienz in der Software-Entwicklung durch Automatisierung der notwendigen Transformationen von abstrakten bzw. formalen Modellen bis zur Implementierung. Dies ist insbesondere dann sinnvoll, wenn die Integrität der ursprünglichen Modelle formal bewiesen werden kann und durch die Transformation gewährleistet wird. Ein Standard zur Spezifikation der Integrität von Softwaremodellen ist die Object Constraint Language (OCL). Eine weitere Forschungsrichtung im Software-Engineering ist die Entwicklung von dynamischen Komponenten-Modellen, die die Komposition von Softwaresystemen im laufenden Betrieb ermöglichen. Dies bedeutet, dass die Systemverifikation im laufenden Betrieb realisiert werden muss. Die meisten der etablierten Verifikationstechniken sind dazu nicht geeignet. In der Diplomarbeit soll ausgehend von diesem Stand der Technik eine Methode zur modellbasierten Verifikation zur Laufzeit entwickelt werden. Insbesondere soll untersucht werden, wie OCL-Constraints zur Laufzeit in ausführbare Software-Artefakte übersetzt und in dem komponentenbasierten System Treaty verwendet werden können

Refactoring for Reuse: An Empirical Study

Refactoring is the de-facto practice to optimize software health. While several studies propose refactoring strategies to optimize software design through applying design patterns and removing design defects, little is known about how developers actually refactor their code to improve its reuse. Therefore, we extract, from 1,828 open source projects, a set of refactorings that were intended to improve the software reusability. We analyze the impact of reusability refactorings on the state-of-the-art reusability metrics, and we compare the distribution of reusability refactoring types, with the distribution of the remaining mainstream refactorings. Overall, we found that the distribution of refactoring types, applied in the context of reusability, is different from the distribution of refactoring types in mainstream development. In the refactorings performed to improve reusability, source files are subject to more design level types of refactorings. Reusability refactorings significantly impact, high-level code elements, such as packages, classes, and methods, while typical refactorings, impact all code elements, including identifiers, and parameters. These findings provide practical insights into the current practice of refactoring in the context of code reuse involving the act of refactoring