Refactoring Swift (iOS/macOS) Code: A Practical Guide

What is this book about?

"Refactoring Swift (iOS/macOS) Code" is a practical guide for developers who want to turn "working" code into elegant, maintainable, and performant code. The book focuses exclusively on the Apple ecosystem: Swift, UIKit, SwiftUI, Combine, Core Data, and other frameworks. You will learn to identify code smells, safely reorganize project structure, and apply modern refactoring practices without risking breaking functionality.

Who is this book for?

• iOS/macOS developers of any level (Junior, Middle, Senior) looking to improve code quality.
• Teams working on legacy Swift projects.
• Programmers who want to master Xcode refactoring tools (Rename, Extract, Move, etc.).
• Those transitioning from Objective-C to Swift and seeking best practices for code organization.

What will you learn?

• How to identify 15+ types of code smells in Swift code (long methods, large classes, excessive dependencies).
• Step-by-step refactoring techniques: extracting methods, replacing conditional operators with polymorphism, encapsulating fields.
• How to refactor ViewController / ViewModel / Redux architectures.
• Performance improvement techniques: eliminating memory leaks (retain cycles), optimizing closures and lazy properties.
• Working with tests: how to refactor without breaking Unit tests, and how to write testable code from scratch.
• Using built-in Xcode tools (Refactor menu, Assistant editor, Preview) and third-party linters (SwiftLint).
• Migrating from UIKit to SwiftUI: refactoring controllers into Views and State models.

Edition features

• All examples tested on Xcode 15+ (Swift 5.9) and iOS 17 / macOS 14.
• Real-world cases from App Store projects: from "spaghetti code" to modular architecture.
• Chapters include checklists and "anti-patterns" with explanations.
• The final chapter — refactoring a complete "ToDo List" application from start to finish.

The book will become an essential reference for every Swift developer striving to write code that is easy to maintain, extend, and hand off to colleagues. Whether you are working on a new project or diving into legacy code, you will find ready-made recipes and strategies here.