Refactoring for Software Design Smells: Managing Technical Debt

Awareness of design smells – indicators of common design problems – helps developers or software engineers understand mistakes made while designing, what design principles were overlooked or misapplied, and what principles need to be applied properly to address those smells through refactoring. Developers and software engineers may "know" principles and patterns, but are not aware of the "smells" that exist in their design because of wrong or mis-application of principles or patterns. These smells tend to contribute heavily to technical debt – further time owed to fix projects thought to be complete – and need to be addressed via proper refactoring.

Refactoring for Software Design Smells presents 25 structural design smells, their role in identifying design issues, and potential refactoring solutions. Organized across common areas of software design, each smell is presented with diagrams and examples illustrating the poor design practices and the problems that result, creating a catalog of nuggets of readily usable information that developers or engineers can apply in their projects. The authors distill their research and experience as consultants and trainers, providing insights that have been used to improve refactoring and reduce the time and costs of managing software projects. Along the way they recount anecdotes from actual projects on which the relevant smell helped address a design issue.

Contains a comprehensive catalog of 25 structural design smells (organized around four fundamental design principles) that contribute to technical debt in software projectsPresents a unique naming scheme for smells that helps understand the cause of a smell as well as points toward its potential refactoringIncludes illustrative examples that showcase the poor design practices underlying a smell and the problems that resultCovers pragmatic techniques for refactoring design smells to manage technical debt and to create and maintain high-quality software in practicePresents insightful anecdotes and case studies drawn from the trenches of real-world projects

Preface

1. Technical Debt
2. Design Smells
3. Abstraction
4. Encapsulation
5. Modularization
6. Hierarchy
7. Smell Sociology
8. Repaying Technical Debt in Practice

Appendix A: List of object-oriented design principles

Appendix B: List of software tools for replaying technical debt

Appendix C: Notations for figures that have been used in the book

Appendix D: Further suggested reading