How often do you hear people say things like this? "Our JavaScript is a mess, but we’re thinking about using [framework of the month]." Like it or not, JavaScript is not going away. No matter what framework or ”compiles-to-js” language or library you use, bugs and performance concerns will always be an issue if the underlying quality of your JavaScript is poor. Rewrites, including porting to the framework of the month, are terribly expensive and unpredictable. The bugs won’t magically go away, and can happily reproduce themselves in a new context. To complicate things further, features will get dropped, at least temporarily. The other popular method of fixing your JS is playing “JavaScript Jenga,” where each developer slowly and carefully takes their best guess at how the out-of-control system can be altered to allow for new features, hoping that this doesn’t bring the whole stack of blocks down. This book provides clear guidance on how best to avoid these pathological approaches to writing JavaScript: Recognize you have a problem with your JavaScript quality. Forgive the code you have now, and the developers who made it. Learn repeatable, memorable, and time-saving refactoring techniques. Apply these techniques as you work, fixing things along the way. Internalize these techniques, and avoid writing as much problematic code to begin with. Bad code doesn’t have to stay that way. And making it better doesn’t have to be intimidating or unreasonably expensive.

How often do you hear people say things like this? "Our JavaScript is a mess, but we’re thinking about using [framework of the month]." Like it or not, JavaScript is not going away. No matter what framework or ”compiles-to-js” language or library you use, bugs and performance concerns will always be an issue if the underlying quality of your JavaScript is poor. Rewrites, including porting to the framework of the month, are terribly expensive and unpredictable. The bugs won’t magically go away, and can happily reproduce themselves in a new context. To complicate things further, features will get dropped, at least temporarily. The other popular method of fixing your JS is playing “JavaScript Jenga,” where each developer slowly and carefully takes their best guess at how the out-of-control system can be altered to allow for new features, hoping that this doesn’t bring the whole stack of blocks down. This book provides clear guidance on how best to avoid these pathological approaches to writing JavaScript: Recognize you have a problem with your JavaScript quality. Forgive the code you have now, and the developers who made it. Learn repeatable, memorable, and time-saving refactoring techniques. Apply these techniques as you work, fixing things along the way. Internalize these techniques, and avoid writing as much problematic code to begin with. Bad code doesn’t have to stay that way. And making it better doesn’t have to be intimidating or unreasonably expensive.

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.

Discover various techniques to develop maintainable code and keep it in shape. Key FeaturesLearn all about refactoring - why it is important and how to do itDiscover easy ways to refactor code with examplesExplore techniques that can be applied to most other programming languagesBook Description Refactoring improves your code without changing its behavior. With refactoring, the best approach is to apply small targeted changes to a codebase. Instead of doing a huge sweeping change to your code, refactoring is better as a long-term and continuous enterprise. Refactoring TypeScript explains how to spot bugs and remove them from your code. You’ll start by seeing how wordy conditionals, methods, and null checks make code unhealthy and unstable. Whether it is identifying messy nested conditionals or removing unnecessary methods, this book will show various techniques to avoid these pitfalls and write code that is easier to understand, maintain, and test. By the end of the book, you’ll have learned some of the main causes of unhealthy code, tips to identify them and techniques to address them. What you will learnSpot and fix common code smells to create code that is easier to read and understandDiscover ways to identify long methods and refactor themCreate objects that keep your code flexible, maintainable, and testableApply the Single Responsibility Principle to develop less-coupled codeDiscover how to combine different refactoring techniquesLearn ways to solve the issues caused by overusing primitivesWho this book is for This book is designed for programmers who are looking to explore various refactoring techniques to develop healthy and maintainable code. Some experience in JavaScript and TypeScript can help you easily grasp the concepts explained in this book.

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

Get more out of your legacy systems: more performance, functionality, reliability, and manageability Is your code easy to change? Can you get nearly instantaneous feedback when you do change it? Do you understand it? If the answer to any of these questions is no, you have legacy code, and it is draining time and money away from your development efforts. In this book, Michael Feathers offers start-to-finish strategies for working more effectively with large, untested legacy code bases. This book draws on material Michael created for his renowned Object Mentor seminars: techniques Michael has used in mentoring to help hundreds of developers, technical managers, and testers bring their legacy systems under control. The topics covered include Understanding the mechanics of software change: adding features, fixing bugs, improving design, optimizing performance Getting legacy code into a test harness Writing tests that protect you against introducing new problems Techniques that can be used with any language or platform—with examples in Java, C++, C, and C# Accurately identifying where code changes need to be made Coping with legacy systems that aren't object-oriented Handling applications that don't seem to have any structure This book also includes a catalog of twenty-four dependency-breaking techniques that help you work with program elements in isolation and make safer changes.

Like any other software system, Web sites gradually accumulate “cruft” over time. They slow down. Links break. Security and compatibility problems mysteriously appear. New features don’t integrate seamlessly. Things just don’t work as well. In an ideal world, you’d rebuild from scratch. But you can’t: there’s no time or money for that. Fortunately, there’s a solution: You can refactor your Web code using easy, proven techniques, tools, and recipes adapted from the world of software development. In Refactoring HTML, Elliotte Rusty Harold explains how to use refactoring to improve virtually any Web site or application. Writing for programmers and non-programmers alike, Harold shows how to refactor for better reliability, performance, usability, security, accessibility, compatibility, and even search engine placement. Step by step, he shows how to migrate obsolete code to today’s stable Web standards, including XHTML, CSS, and REST—and eliminate chronic problems like presentation-based markup, stateful applications, and “tag soup.” The book’s extensive catalog of detailed refactorings and practical “recipes for success” are organized to help you find specific solutions fast, and get maximum benefit for minimum effort. Using this book, you can quickly improve site performance now—and make your site far easier to enhance, maintain, and scale for years to come. Topics covered include • Recognizing the “smells” of Web code that should be refactored • Transforming old HTML into well-formed, valid XHTML, one step at a time • Modernizing existing layouts with CSS • Updating old Web applications: replacing POST with GET, replacing old contact forms, and refactoring JavaScript • Systematically refactoring content and links • Restructuring sites without changing the URLs your users rely upon This book will be an indispensable resource for Web designers, developers, project managers, and anyone who maintains or updates existing sites. It will be especially helpful to Web professionals who learned HTML years ago, and want to refresh their knowledge with today’s standards-compliant best practices. This book will be an indispensable resource for Web designers, developers, project managers, and anyone who maintains or updates existing sites. It will be especially helpful to Web professionals who learned HTML years ago, and want to refresh their knowledge with today’s standards-compliant best practices.

JavaScript is no longer to be feared or loathed - the world's most popular and ubiquitous language has evolved into a respectable language. Whether you're writing frontend applications or server side code, the phenomenal features from ES6 and beyond - like the rest operator, generators, destructuring, object literals, arrow functions, modern classes, promises, async, and metaprogramming capabilities - will get you excited and eager to program with JavaScript. You've found the right book to get started quickly and dive deep into the essence of modern JavaScript. Learn practical tips to apply the elegant parts of the language and the gotchas to avoid. JavaScript is a black swan that no one, including the author of the language, thought would become a popular and ubiquitous language. Not long ago, it was the most hated and feared language you could use to program the web. JavaScript ES6 and beyond has gone through a significant makeover. Troublesome features have been replaced with better, elegant, more reliable alternatives. This book includes many practical examples and exercises to help you learn in depth. It will not bore you with idiosyncrasies and arcane details intended for bad interview questions. Instead, it takes you into key features that you can readily use in your day-to-day projects. Whether you program the frontend or the server side, you can now write concise, elegant, and expressive JavaScript with newer features like default parameters, template literals, rest and spread operators, destructuring, arrow functions, and generators. Take it up a notch with features like infinite series, promises, async, and metaprogramming to create flexible, powerful, and extensible libraries. While the evolved features of the language will draw you in, the hundreds of examples in this book will pin the concepts down, for you to use on your projects. Take command of modern JavaScript and unlock your potential to create powerful applications. What You Need: To try out the examples in the book you will need a computer with Node.js, a text editor, and a browser like Chrome installed in it.

Kerievsky lays the foundation for maximizing the use of design patterns by helping the reader view them in the context of refactorings. He ties together two of the most popular methods in software engineering today--refactoring and design patterns--as he helps the experienced developer create more robust software.

JavaScript Allongé solves two important problems for the ambitious JavaScript programmer. First, JavaScript Allongé gives you the tools to deal with JavaScript bugs, hitches, edge cases, and other potential pitfalls. There are plenty of good directions for how to write JavaScript programs. If you follow them without alteration or deviation, you will be satisfied. Unfortunately, software is a complex thing, full of interactions and side-effects. Two perfectly reasonable pieces of advice when taken separately may conflict with each other when taken together. An approach may seem sound at the outset of a project, but need to be revised when new requirements are discovered. When you “leave the path” of the directions, you discover their limitations. In order to solve the problems that occur at the edges, in order to adapt and deal with changes, in order to refactor and rewrite as needed, you need to understand the underlying principles of the JavaScript programming language in detail. You need to understand why the directions work so that you can understand how to modify them to work properly at or beyond their original limitations. That’s where JavaScript Allongé comes in. JavaScript Allongé is a book about programming with functions, because JavaScript is a programming language built on flexible and powerful functions. JavaScript Allongé begins at the beginning, with values and expressions, and builds from there to discuss types, identity, functions, closures, scopes, and many more subjects up to working with classes and instances. In each case, JavaScript Allongé takes care to explain exactly how things work so that when you encounter a problem, you’ll know exactly what is happening and how to fix it. Second, JavaScript Allongé provides recipes for using functions to write software that is simpler, cleaner, and less complicated than alternative approaches that are object-centric or code-centric. JavaScript idioms like function combinators and decorators leverage JavaScript’s power to make code easier to read, modify, debug and refactor, thus avoiding problems before they happen. JavaScript Allongé teaches you how to handle complex code, and it also teaches you how to simplify code without dumbing it down. As a result, JavaScript Allongé is a rich read releasing many of JavaScript’s subtleties, much like the Café Allongé beloved by coffee enthusiasts everywhere. License: CC BY-SA 3.0 Source is available from Github * https://github.com/justinkelly/javascript-allonge