Refactoring Swift (iOS/macOS) Code

The book "Refactoring Swift (iOS/macOS) Code" is a practical guide for developers seeking to improve the quality of their Swift applications. Unlike abstract theoretical materials, this book offers concrete, proven refactoring methods adapted to the Apple ecosystem.

You will learn how to turn tangled, hard-to-maintain code into a clean, modular, and testable system. The book covers all stages of refactoring: from identifying "code smells" to safely making changes and testing results.

Who this book is for:

• iOS/macOS developers with 1+ year of experience who want to improve their code quality
• Teams working on legacy projects needing a systematic approach to improving the codebase
• Team leads and architects wanting to instill a culture of refactoring in their team
• Developers transitioning from Objective-C to Swift and facing the need to rework old code

What you will learn from this book:

• Basic principles of refactoring and their application in Swift (SOLID, KISS, DRY)
• How to safely reorganize code without risking breaking existing functionality
• Refactoring techniques for UIKit and SwiftUI: extracting ViewModel, state optimization, working with Combine
• How to improve application architecture: transitioning from Massive View Controller to MVP, MVVM, VIPER, or TCA
• Performance improvement methods: memory optimization, eliminating leaks, loop refactoring
• Working with tests during refactoring: how to write tests for legacy code and use TDD
• Refactoring the network layer, data storage, and dependencies (DI)
• Practical examples from real projects: step-by-step analysis with "before" and "after"

The book is structured on the principle of "from simple to complex." Starting with basic techniques (renaming, extracting methods), you will gradually move to complex transformations: introducing protocols, creating factories, refactoring asynchronous code with async/await.

Special attention is paid to the safety of refactoring. You will learn how to set up the environment to minimize risks: using Xcode tools (Refactor, Rename, Extract), working with git, automated testing, and code review.

Each chapter contains practical exercises and checklists for self-assessment. At the end of the book, you will find a ready-made refactoring strategy for projects of any size.

This book will become your reliable assistant in the fight against technical debt and will help you create applications that are easy to develop and maintain for years.