Refactoring is about improving the design of existing code. It is the process of changing a software system in such a way that it does not alter the external behavior of the code, yet improves its internal structure. With refactoring you can even take a bad design and rework it into a good one. This book offers a thorough discussion of the principles of refactoring, including where to spot opportunities for refactoring, and how to set up the required tests. There is also a catalog of more than 40 proven refactorings with details as to when and why to use the refactoring, step by step instructions for implementing it, and an example illustrating how it works The book is written using Java as its principle language, but the ideas are applicable to any OO language.
Features
The first update to a classic that is the standard reference for refactoring in over 15 years
Enhanced, web-based features including interactive examples, video snippets, code highlighting
Extensive use of JavaScript examples
New to This Edition
Martin Fowler is retaining everything that made Refactoring one of the world’s most popular and influential computer books, while updating with JavaScript examples throughout (to address many programmers’ current preferences) and reflecting today’s programming paradigms. The book’s catalog of individual refactorings has been updated, revised, and expanded.

Testing is a key component of agile development. The widespread adoption of agile methods has brought the need for effective testing into the limelight, and agile projects have transformed the role of testers. Much of a tester's function, however, remains largely misunderstood. What is the true role of a tester? Do agile teams actually need members with QA backgrounds? What does it really mean to be an "agile tester?" Two of the industry's most experienced agile testing practitioners and consultants, Lisa Crispin and Janet Gregory, have teamed up to bring you the definitive answers to these questions and many others. In Agile Testing, Crispin and Gregory define agile testing and illustrate the tester's role with examples from real agile teams. They teach you how to use the agile testing quadrants to identify what testing is needed, who should do it, and what tools might help. The book chronicles an agile software development iteration from the viewpoint of a tester and explains the seven key success factors of agile testing. Readers will come away from this book understanding * How to get testers engaged in agile development * Where testers and QA managers fit on an agile team * What to look for when hiring an agile tester * How to transition from a traditional cycle to agile development * How to complete testing activities in short iterations * How to use tests to successfully guide development * How to overcome barriers to test automationThis book is a must for agile testers, agile teams, their managers, and their customers.

As Python continues to grow in popularity, projects are becoming larger and more complex. Many Python developers are now taking an interest in high-level software architecture patterns such as hexagonal/clean architecture, event-driven architecture, and strategic patterns prescribed by domain-driven design (DDD). But translating those patterns into Python isn’t always straightforward.
With this practical guide, Harry Percival and Bob Gregory from MADE.com introduce proven architectural design patterns to help Python developers manage application complexity. Each pattern is illustrated with concrete examples in idiomatic Python that explain how to avoid some of the unnecessary verbosity of Java and C# syntax. You’ll learn how to implement each of these patterns in a Pythonic way.
Architectural design patterns include:
Dependency inversion, and its links to ports and adapters (hexagonal/clean architecture)
Domain-driven design’s distinction between entities, value objects, and aggregates
Repository and Unit of Work patterns for persistent storage
Events, commands, and the message bus
Command Query Responsibility Segregation (CQRS)
Event-driven architecture and reactive microservices

Automated testing is a cornerstone of agile development. An effective testing strategy will deliver new functionality more aggressively, accelerate user feedback, and improve quality. However, for many developers, creating effective automated tests is a unique and unfamiliar challenge. xUnit Test Patterns is the definitive guide to writing automated tests using xUnit, the most popular unit testing framework in use today. Agile coach and test automation expert Gerard Meszaros describes 68 proven patterns for making tests easier to write, understand, and maintain. He then shows you how to make them more robust and repeatable--and far more cost-effective. Loaded with information, this book feels like three books in one. The first part is a detailed tutorial on test automation that covers everything from test strategy to in-depth test coding. The second part, a catalog of 18 frequently encountered "test smells," provides trouble-shooting guidelines to help you determine the root cause of problems and the most applicable patterns. The third part contains detailed descriptions of each pattern, including refactoring instructions illustrated by extensive code samples in multiple programming languages. Topics covered include * Writing better tests--and writing them faster * The four phases of automated tests: fixture setup, exercising the system under test, result verification, and fixture teardown * Improving test coverage by isolating software from its environment using Test Stubs and Mock Objects * Designing software for greater testability * Using test "smells" (including code smells, behavior smells, and project smells) to spot problems and know when and how to eliminate them * Refactoring tests for greater simplicity, robustness, and execution speed This book will benefit developers, managers, and testers working with any agile or conventional development process, whether doing test-driven development or writing the tests last. While the patterns and smells are especially applicable to all members of the xUnit family, they also apply to next-generation behavior-driven development frameworks such as RSpec and JBehave and to other kinds of test automation tools, including recorded test tools and data-driven test tools such as Fit and FitNesse. Visual Summary of the Pattern Language Foreword Preface Acknowledgments Introduction Refactoring a Test PART I: The Narratives Chapter 1 A Brief Tour Chapter 2 Test Smells Chapter 3 Goals of Test Automation Chapter 4 Philosophy of Test Automation Chapter 5 Principles of Test Automation Chapter 6 Test Automation Strategy Chapter 7 xUnit Basics Chapter 8 Transient Fixture Management Chapter 9 Persistent Fixture Management Chapter 10 Result Verification Chapter 11 Using Test Doubles Chapter 12 Organizing Our Tests Chapter 13 Testing with Databases Chapter 14 A Roadmap to Effective Test Automation PART II: The Test Smells Chapter 15 Code Smells Chapter 16 Behavior Smells Chapter 17 Project Smells PART III: The Patterns Chapter 18 Test Strategy Patterns Chapter 19 xUnit Basics Patterns Chapter 20 Fixture Setup Patterns Chapter 21 Result Verification Patterns Chapter 22 Fixture Teardown Patterns Chapter 23 Test Double Patterns Chapter 24 Test Organization Patterns Chapter 25 Database Patterns Chapter 26 Design-for-Testability Patterns Chapter 27 Value Patterns PART IV: Appendixes Appendix A Test Refactorings Appendix B xUnit Terminology Appendix C xUnit Family Members Appendix D Tools Appendix E Goals and Principles Appendix F Smells, Aliases, and Causes Appendix G Patterns, Aliases, and Variations Glossary References Index

Practical Software Architecture Solutions from the Legendary Robert C. Martin (“Uncle Bob”)
By applying universal rules of software architecture, you can dramatically improve developer productivity throughout the life of any software system. Now, building upon the success of his best-selling books Clean Code and The Clean Coder, legendary software craftsman Robert C. Martin (“Uncle Bob”) reveals those rules and helps you apply them.
Martin’s Clean Architecture doesn’t merely present options. Drawing on over a half-century of experience in software environments of every imaginable type, Martin tells you what choices to make and why they are critical to your success. As you’ve come to expect from Uncle Bob, this book is packed with direct, no-nonsense solutions for the real challenges you’ll face—the ones that will make or break your projects.
Learn what software architects need to achieve—and core disciplines and practices for achieving it
Master essential software design principles for addressing function, component separation, and data management
See how programming paradigms impose discipline by restricting what developers can do
Understand what’s critically important and what’s merely a “detail”
Implement optimal, high-level structures for web, database, thick-client, console, and embedded applications
Define appropriate boundaries and layers, and organize components and services
See why designs and architectures go wrong, and how to prevent (or fix) these failures
Clean Architecture is essential reading for every current or aspiring software architect, systems analyst, system designer, and software manager—and for every programmer who must execute someone else’s designs.
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The Rust programming language offers the rare and valuable combination of statically verified memory safety and low-level control. Imagine C++ but without dangling pointers, null pointer dereferences, leaks, or buffer overruns. With this practical guide, systems programmers will understand Rust’s rules clearly and economically. You’ll learn how to express programs that Rust can prove are free of a broad class of common errors.
Rust brings the benefits of an expressive modern type system to systems programming. Authors Jim Blandy and Jason Orendorff demonstrate how Rust’s features put programmers in control over memory consumption and processor use, combining predictable performance with memory safety and trustworthy concurrency.
You’ll learn:
How to write fast, safe, concurrent programs in Rust
Rust’s rules for managing memory efficiently, including ownership, borrowing, moves, and lifetimes
How to design interfaces that fit well into the Rust ecosystem
Rust’s all-purpose Cargo tool for building, testing, and managing Rust packages
High-level features like traits, generics, closures, and iterators that make Rust productive and flexible