A Systematic Aspect-Oriented Refactoring and Testing Strategy, and its Application to JHotDraw

TL;DR

This paper presents a systematic refactoring and testing strategy for migrating legacy software to aspect-oriented programming, demonstrated on JHotDraw, enhancing modularity and maintainability.

Contribution

It introduces a structured approach for safe, incremental migration to aspect-oriented systems and offers insights into designing aspect languages for better support of such migrations.

Findings

Applied the strategy to JHotDraw successfully.

Identified generic refactorings for aspect-oriented migration.

Linked crosscutting concerns to aspect language features.

Abstract

Aspect oriented programming aims at achieving better modularization for a system's crosscutting concerns in order to improve its key quality attributes, such as evolvability and reusability. Consequently, the adoption of aspect-oriented techniques in existing (legacy) software systems is of interest to remediate software aging. The refactoring of existing systems to employ aspect-orientation will be considerably eased by a systematic approach that will ensure a safe and consistent migration. In this paper, we propose a refactoring and testing strategy that supports such an approach and consider issues of behavior conservation and (incremental) integration of the aspect-oriented solution with the original system. The strategy is applied to the JHotDraw open source project and illustrated on a group of selected concerns. Finally, we abstract from the case study and present a number of generic refactorings which contribute to an incremental aspect-oriented refactoring process and associate particular types of crosscutting concerns to the model and features of the employed aspect language. The contributions of this paper are both in the area of supporting migration towards aspect-oriented solutions and supporting the development of aspect languages that are better suited for such migrations.