Refactoring In Ruby

The Definitive Refactoring Guide, Fully Revamped for Ruby With refactoring, programmers can transform even the most chaotic software into well-designed systems that are far easier to evolve and maintain. What’s more, they can do it one step at a time, through a series of simple, proven steps. Now, there’s an authoritative and extensively updated version of Martin Fowler’s classic refactoring book that utilizes Ruby examples and idioms throughout–not code adapted from Java or any other environment. The authors introduce a detailed catalog of more than 70 proven Ruby refactorings, with specific guidance on when to apply each of them, step-by-step instructions for using them, and example code illustrating how they work. Many of the authors’ refactorings use powerful Ruby-specific features, and all code samples are available for download. Leveraging Fowler’s original concepts, the authors show how to perform refactoring in a controlled, efficient, incremental manner, so you methodically improve your code’s structure without introducing new bugs. Whatever your role in writing or maintaining Ruby code, this book will be an indispensable resource. This book will help you Understand the core principles of refactoring and the reasons for doing it Recognize “bad smells” in your Ruby code Rework bad designs into well-designed code, one step at a time Build tests to make sure your refactorings work properly Understand the challenges of refactoring and how they can be overcome Compose methods to package code properly Move features between objects to place responsibilities where they fit best Organize data to make it easier to work with Simplify conditional expressions and make more effective use of polymorphism Create interfaces that are easier to understand and use Generalize more effectively Perform larger refactorings that transform entire software systems and may take months or years Successfully refactor Ruby on Rails code

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

The Complete Guide to Avoiding and Fixing Common Rails 3 Code and Design Problems As developers worldwide have adopted the powerful Ruby on Rails web framework, many have fallen victim to common mistakes that reduce code quality, performance, reliability, stability, scalability, and maintainability. RailsTM AntiPatterns identifies these widespread Rails code and design problems, explains why they’re bad and why they happen—and shows exactly what to do instead. The book is organized into concise, modular chapters—each outlines a single common AntiPattern and offers detailed, cookbook-style code solutions that were previously difficult or impossible to find. Leading Rails developers Chad Pytel and Tammer Saleh also offer specific guidance for refactoring existing bad code or design to reflect sound object-oriented principles and established Rails best practices. With their help, developers, architects, and testers can dramatically improve new and existing applications, avoid future problems, and establish superior Rails coding standards throughout their organizations. This book will help you understand, avoid, and solve problems with Model layer code, from general object-oriented programming violations to complex SQL and excessive redundancy Domain modeling, including schema and database issues such as normalization and serialization View layer tools and conventions Controller-layer code, including RESTful code Service-related APIs, including timeouts, exceptions, backgrounding, and response codes Third-party code, including plug-ins and gems Testing, from test suites to test-driven development processes Scaling and deployment Database issues, including migrations and validations System design for “graceful degradation” in the real world

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

Refactoring is gaining momentum amongst the object oriented programming community. It can transform the internal dynamics of applications and has the capacity to transform bad code into good code. This book offers an introduction to refactoring.

The Complete Guide to Writing More Maintainable, Manageable, Pleasing, and Powerful Ruby Applications Ruby’s widely admired ease of use has a downside: Too many Ruby and Rails applications have been created without concern for their long-term maintenance or evolution. The Web is awash in Ruby code that is now virtually impossible to change or extend. This text helps you solve that problem by using powerful real-world object-oriented design techniques, which it thoroughly explains using simple and practical Ruby examples. Sandi Metz has distilled a lifetime of conversations and presentations about object-oriented design into a set of Ruby-focused practices for crafting manageable, extensible, and pleasing code. She shows you how to build new applications that can survive success and repair existing applications that have become impossible to change. Each technique is illustrated with extended examples, all downloadable from the companion Web site, poodr.info. The first title to focus squarely on object-oriented Ruby application design, Practical Object-Oriented Design in Ruby will guide you to superior outcomes, whatever your previous Ruby experience. Novice Ruby programmers will find specific rules to live by; intermediate Ruby programmers will find valuable principles they can flexibly interpret and apply; and advanced Ruby programmers will find a common language they can use to lead development and guide their colleagues. This guide will help you Understand how object-oriented programming can help you craft Ruby code that is easier to maintain and upgrade Decide what belongs in a single Ruby class Avoid entangling objects that should be kept separate Define flexible interfaces among objects Reduce programming overhead costs with duck typing Successfully apply inheritance Build objects via composition Design cost-effective tests Solve common problems associated with poorly designed Ruby code

Praise for Design Patterns in Ruby "Design Patterns in Ruby documents smart ways to resolve many problems that Ruby developers commonly encounter. Russ Olsen has done a great job of selecting classic patterns and augmenting these with newer patterns that have special relevance for Ruby. He clearly explains each idea, making a wealth of experience available to Ruby developers for their own daily work." —Steve Metsker, Managing Consultant with Dominion Digital, Inc. "This book provides a great demonstration of the key 'Gang of Four' design patterns without resorting to overly technical explanations. Written in a precise, yet almost informal style, this book covers enough ground that even those without prior exposure to design patterns will soon feel confident applying them using Ruby. Olsen has done a great job to make a book about a classically 'dry' subject into such an engaging and even occasionally humorous read." —Peter Cooper "This book renewed my interest in understanding patterns after a decade of good intentions. Russ picked the most useful patterns for Ruby and introduced them in a straightforward and logical manner, going beyond the GoF's patterns. This book has improved my use of Ruby, and encouraged me to blow off the dust covering the GoF book." —Mike Stok "Design Patterns in Ruby is a great way for programmers from statically typed objectoriented languages to learn how design patterns appear in a more dynamic, flexible language like Ruby." —Rob Sanheim, Ruby Ninja, Relevance Most design pattern books are based on C++ and Java. But Ruby is different—and the language's unique qualities make design patterns easier to implement and use. In this book, Russ Olsen demonstrates how to combine Ruby's power and elegance with patterns, and write more sophisticated, effective software with far fewer lines of code. After reviewing the history, concepts, and goals of design patterns, Olsen offers a quick tour of the Ruby language—enough to allow any experienced software developer to immediately utilize patterns with Ruby. The book especially calls attention to Ruby features that simplify the use of patterns, including dynamic typing, code closures, and "mixins" for easier code reuse. Fourteen of the classic "Gang of Four" patterns are considered from the Ruby point of view, explaining what problems each pattern solves, discussing whether traditional implementations make sense in the Ruby environment, and introducing Ruby-specific improvements. You'll discover opportunities to implement patterns in just one or two lines of code, instead of the endlessly repeated boilerplate that conventional languages often require. Design Patterns in Ruby also identifies innovative new patterns that have emerged from the Ruby community. These include ways to create custom objects with metaprogramming, as well as the ambitious Rails-based "Convention Over Configuration" pattern, designed to help integrate entire applications and frameworks. Engaging, practical, and accessible, Design Patterns in Ruby will help you build better software while making your Ruby programming experience more rewarding.