Emergent Design: The Evolutionary Nature of Professional Software Development

Description

For software to consistently deliver promised results, software development must mature into a true profession. Emergent Design points the way. As software continues to evolve and mature, software development processes become more complicated, relying on a variety of methodologies and approaches. This book illuminates the path to building the next generation of software. Author Scott L. Bain integrates the best of today’s most important development disciplines into a unified, streamlined, realistic, and fully actionable approach to developing software. Drawing on patterns, refactoring, and test-driven development, Bain offers a blueprint for moving efficiently through the entire software lifecycle, smoothly managing change, and consistently delivering systems that are robust, reliable, and cost-effective. Reflecting a deep understanding of the natural flow of system development, Emergent Design helps developers work with the flow, instead of against it. Bain introduces the principles and practices of emergent design one step at a time, showing how to promote the natural evolution of software systems over time, making systems work better and provide greater value. To illuminate his approach, Bain presents code examples wherever necessary and concludes with a complete project case study. This book provides developers, project leads, and testers powerful new ways to collaborate, achieve immediate goals, and build systems that improve in quality with each iteration. Coverage includes How to design software in a more natural, evolutionary, and professional way How to use the “open-closed” principle to mitigate risks and eliminate waste How and when to test your design throughout the development process How to translate design principles into practices that actually lead to better code How to determine how much design is enough How refactoring can help you reduce over-design and manage change more effectively The book’s companion Web site, www.netobjectives.com/resources, provides updates, links to related materials, and support for discussions of the book’s content. Emergent Design Contents Series Foreword Preface Acknowledgments About the Author Chapter 1 Software as a Profession How Long Have Human Beings Been Making Software? What Sort of Activity Is Software Development? What Is Missing? Who Is Responsible? Uniqueness Chapter 2 Out of the Closet, Off to the Moon Patterns and Professionalism in Software Development Andrea's Closet Off to the Moon Forces Lead to Forces Different Forces, Different Design And There Are More Contextual Forces The Costs and Benefits On to Mars The Value of Patterns Summary Chapter 3 The Nature of Software Development We Fail Too Much Definitions of Success The Standish Group Doing the Wrong Things Doing the Things Wrong Time Goes By, Things Improve One Reason: The Civil Engineering Analogy Giving Up Hope Ignoring Your Mother Bridges Are Hard, Software Is Soft We Swim in an Ocean of Change Accept Change Embrace Change Capitalize on Change A Better Analogy: Evolving Systems Summary Chapter 4 Evolution in Code: Stage 1 Procedural Logic Replaced with Object Structure The Origins of Object Orientations and Patterns An Example: Simple Conditionals and the Proxy Pattern The Next Step: Either This or That Why Bother? One Among Many Summary Chapter 5 Using and Discovering Patterns Design from Context: More Carpentry from Scott Patterns Lead to Another Cognitive Perspective Patterns Help Give Us a Language for Discussing Design Patterns in This Book Summary Chapter 6 Building a Pyramid Elements of the Profession A Visual Representation Summary Chapter 7 Paying Attention to Qualities and Pathologies Encapsulation Cohesion Method Cohesion Cohesion of Perspective Level Class Cohesion How Cohesive Is Cohesive Enough? Coupling Intentional Coupling Versus Accidental Coupling Types of Coupling Redundancy Redundancy and Coupling Testability Readability Pathologies Indicators of Weak Cohesion Indicators of Accidental or Illogical Coupling Indicators of Redundancy Summary Chapter 8 Paying Attention to Principles and Wisdom Separating Use from Creation Fowler's Perspectives Another Kind of Perspective The Perspective of Use A Separate Perspective: Creation Considering Construction Details Last The Real World The Open-Closed Principle Open-Closed at the Class Level Open-Closed at the Method Level The Dependency Inversion Principle Advice from the Gang of Four Designing to the Interface of a Method Designing to the Interface of a Class GoF: Favor Object Aggregation Over Class Inheritance GoF: Consider What Should Be Variable in Your Design and Encapsulate the Concept That Varies Summary Chapter 9 Paying Attention to Practices Consistent Coding Style Comments Naming Classes, Methods, and Variables Virtues of Coding Standards Programming by Intention Are They Really All Private? Encapsulating the Constructor Principles Versus Practices Making the Decision Commonality-Variability Analysis Practices and Freedom Summary Chapter 10 Paying Attention to Disciplines: Unit Testing Economies of Testing Unit Testing Up-Front Testing JUnit Framework JUnit Basics JUnit Examples Rule.java: Code First, Then Test RuleContainer.java: Test First, Then Code Eliminating Redundancy: @Before and @After Automating Tests in Batches Exceptions and Unit Testing Mock Objects MockObject Frameworks Faking It Dependency Injection and the Endo-Testing Technique Endo-Testing Summary Chapter 11 Paying Attention to Disciplines: Refactoring Refactoring Bad Code Refactoring Good Code Structural Changes Versus Functional Changes Refactoring Helps You Choose Your Battles Patterns Can Be Targets of Refactoring Avoiding Refactoring: Prefactoring The Mechanics of Refactoring Refactoring Legacy Code Summary Chapter 12 Test-Driven Development What Makes Development Test-Driven? Test-Driven Versus Test-First Designing from the Perspective of the Unit Test Testing and Quality Testing and Cohesion Testing and Coupling Testing and Redundancy Test-Driven Development and Patterns The Strategy Pattern Turtles All the Way Down Mock Object/Mock Turtles Mock Objects Mock Turtles Testing the Decorator Pattern Summary Chapter 13 Patterns and Forces Making Decisions in an Evolving Design Christopher Alexander and Forces The Signal Processor Example The PKZip Example Testing and Forces More Choices, More Forces Summary Chapter 14 Emergent Design: A Case Study The Problem Domain: The MWave Corporation The Teams The Simplest Thing That Could Possibly Work A New Requirement: Complex Machines Oh, By the Way More Good News Summary: What a Long, Strange Trip It Has Been Chapter 15 A Conclusion: 2020 Appendix A: Evolutionary Paths Encapsulated Constructor to Singleton Programming-by-Intention to Encapsulated Constructor to Strategy (Varying on an Issue Extrinsic to the Client) Programming-by-Intention to Encapsulated Constructor to Strategy (Varying on an Issue Intrinsic to the Client) Programming-by-Intention to Encapsulated Constructor to Chain of Responsibility (Varying on an Issue Extrinsic to the Client) Programming-by-Intention to Encapsulated Constructor to Chain of Responsibility (Varying on an Issue Intrinsic to the Client) Encapsulated Construction to Strategy to Singleton (Object Factory) to Adapter/Façade Encapsulated Constructor to Proxy to Decorator with Singleton (Object Factory) Appendix B: Overview of Patterns Used in the Examples The Abstract Factory Pattern Contextual Forces Implementation Forces Consequent Forces The Adapter Pattern Contextual Forces Implementation Forces Consequent Forces The Bridge Pattern Contextual Forces Implementation Forces Consequent Forces The Chain of Responsibility Pattern Contextual Forces Implementation Forces Consequent Forces Chain of Responsibility: The Poker Example The Composite Pattern Contextual Forces Implementation Forces Consequent Forces The Decorator Pattern Contextual Forces Implementation Forces Consequent Forces The Façade Pattern Contextual Forces Implementation Forces Consequent Forces The Proxy Pattern Contextual Forces Implementation Forces Consequent Forces The Singleton Pattern Contextual Forces Implementation Forces Consequent Forces The Strategy Pattern Contextual Forces Implementation Forces Consequent Forces The Template Method Contextual Forces Implementation Forces Consequent Forces Appendix C: The Principle of the Useful Illusion My View An Alternate View Bibliography Index A B C D E F G H I J K L M N O P Q R S T U V W Y–Z