Home > Store

Refactoring in Ruby

Register your product to gain access to bonus material or receive a coupon.

Refactoring in Ruby

Book

  • Sorry, this book is no longer in print.
Not for Sale

eBook

  • Your Price: $34.39
  • List Price: $42.99
  • Includes EPUB and PDF
  • About eBook Formats
  • This eBook includes the following formats, accessible from your Account page after purchase:

    ePub EPUB The open industry format known for its reflowable content and usability on supported mobile devices.

    Adobe Reader PDF The popular standard, used most often with the free Acrobat® Reader® software.

    This eBook requires no passwords or activation to read. We customize your eBook by discreetly watermarking it with your name, making it uniquely yours.

Description

  • Copyright 2010
  • Edition: 1st
  • Book
  • ISBN-10: 0-321-54504-4
  • ISBN-13: 978-0-321-54504-6

The First Hands-On, Practical, All-Ruby Refactoring Workbook!

 

Refactoring–the art of improving the design of existing code–has taken the world by storm. So has Ruby. Now, for the first time, there’s a refactoring workbook designed from the ground up for the dynamic Ruby language.

Refactoring in Ruby gives you all the realistic, hands-on practice you need to refactor Ruby code quickly and effectively. You’ll discover how to recognize “code smells,” which signal opportunities for improvement, and then perfect your program’s design one small, safe step at a time.

The book shows you when and how to refactor with both legacy code and during new test-driven development, and walks you through real-world refactoring in detail. The workbook concludes with several applications designed to help practice refactoring in realistic domains, plus a handy code review checklist you’ll refer to again and again. Along the way, you’ll learn powerful lessons about designing higher quality Ruby software–lessons that will enable you to experience the joy of writing consistently great code.

Refactoring in Ruby will help you

  • Recognize why poor code design occurs, so you can prevent it from occurring in your own code
  • Master better design techniques that lead to more efficient, reliable, and maintainable software
  • Fix code that’s too long, large, or difficult to follow
  • Ferret out duplication, and express each idea “once and only once”
  • Recognize missing or inadequately formed classes
  • Simplify overly complex relationships between classes and their subclasses
  • Achieve the right balance of responsibilities among objects
  • Make your code easier to test and change
  • Cope with incomplete library modules, and fix runaway dependencies
  • Learn the next steps to take after you refactor

Sample Content

Sample Pages

Download the sample pages (includes Chapter 1 and Index)

Table of Contents

Foreword xvii

Preface xix

About the Authors xxiii

Part I: The Art of Refactoring 1

 

Chapter 1: A Refactoring Example 3

Sparkline Script 3

Consistency 6

Testability 8

Greedy Methods 8

Greedy Module 9

Comments 10

Whole Objects 11

Feature Envy 12

Uncommunicative Names 14

Derived Values 15

Wabi-Sabi 17

Summing Up 18

What’s Next 18

Chapter 2: The Refactoring Cycle 19

What Is Refactoring? 19

Smells Are Problems 20

The Refactoring Cycle 21

When Are We Done? 21

Test-Driven/Behavior-Driven Development 22

Exercise 23

What’s Next 23

Chapter 3: Refactoring Step by Step 25

The Refactoring Environment 25

Inside a Refactoring 26

The Generic Refactoring Micro-Process 30

Exercises 33

What’s Next 33

Chapter 4: Refactoring Practice 35

Read Other Books 35

Practice Refactoring 35

Exercises to Try 36

Participate in the Community 37

Exercise 38

What’s Next 38

Part II: Code Smells 39

 

Chapter 5: Measurable Smells 41

Comments 42

Long Method 44

Large Module 46

Long Parameter List 48

Exercises 49

Chapter 6: Names 57

Type Embedded in Name 59

Uncommunicative Name 60

Inconsistent Names 61

Exercises 62

Chapter 7: Unnecessary Complexity 65

Dead Code 66

Speculative Generality 68

Greedy Method 70

Procedural Code 72

Dynamic Code Creation 74

Exercises 76

Chapter 8: Duplication 79

Derived Value 80

Repeated Value 81

Duplicated Code 83

Alternative Modules with Different Interfaces 85

Exercises 86

Chapter 9: Conditional Logic 93

Nil Check 94

Special Case 96

Complicated Boolean Expression 98

Control Coupling 100

Simulated Polymorphism 101

Exercises 103

Chapter 10: Data 107

Open Secret 108

Data Class 110

Data Clump 112

Temporary Field 114

Exercises 115

Chapter 11: Inheritance 125

Implementation Inheritance 126

Refused Bequest 128

Inappropriate Intimacy (Subclass Form) 130

Lazy Class 131

Exercises 133

Chapter 12: Responsibility 135

Feature Envy 136

Utility Function 138

Global Variable 140

Inappropriate Intimacy (General Form) 141

Message Chain 143

Middle Man 145

Greedy Module 146

Exercises 148


Chapter 13: Accommodating Change 153

Divergent Change 154

Shotgun Surgery 156

Parallel Inheritance Hierarchies 158

Combinatorial Explosion 159

Exercises 160

Chapter 14: Libraries 163

Incomplete Library Module 164

Reinvented Wheel 166

Runaway Dependencies 167

Exercises 168

Part III: Programs to Refactor 171

 

Chapter 15: A Simple Game 173

Code 173

Refactoring 175

Development Episodes 180

Chapter 16: Time Recording 183

Preparing the Soil 187

Substitute Algorithm 191

Optional Extras 194

Chapter 17: Calculator 197

Code 198

Refactoring 209

Thank You 211

Part IV: Appendices 213

 

Appendix A: Answers to Selected Questions 215

The Refactoring Cycle 215

Refactoring Step by Step 216

Refactoring Practice 216

Measurable Smells 217

Names 220

Unnecessary Complexity 222

Duplication 225

Conditional Logic 230

Data 233

Inheritance 237

Responsibility 239

Accommodating Change 241

Libraries 244

A Simple Game 246

Time Recording 247

Appendix B: Ruby Refactoring Tools 251

Code Smell Detectors 251

Environments with Refactoring Support 252

Bibliography 253

Index 255

Updates

Submit Errata

More Information

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020