Book excerpt: From learning about the most sought-after design patterns to a comprehensive coverage of architectural patterns and code testing, this book is all you need to write clean, reusable code Key FeaturesWrite clean, reusable and maintainable code, and make the most of the latest Swift version.Analyze case studies of some of the popular open source projects and give your workflow a huge boostChoose patterns such as MVP, MVC, and MVVM depending on the application being builtBook Description Swift keeps gaining traction not only amongst Apple developers but also as a server-side language. This book demonstrates how to apply design patterns and best practices in real-life situations, whether that's for new or already existing projects. You’ll begin with a quick refresher on Swift, the compiler, the standard library, and the foundation, followed by the Cocoa design patterns – the ones at the core of many cocoa libraries – to follow up with the creational, structural, and behavioral patterns as defined by the GoF. You'll get acquainted with application architecture, as well as the most popular architectural design patterns, such as MVC and MVVM, and learn to use them in the context of Swift. In addition, you’ll walk through dependency injection and functional reactive programming. Special emphasis will be given to techniques to handle concurrency, including callbacks, futures and promises, and reactive programming. These techniques will help you adopt a test-driven approach to your workflow in order to use Swift Package Manager and integrate the framework into the original code base, along with Unit and UI testing. By the end of the book, you'll be able to build applications that are scalable, faster, and easier to maintain. What you will learnWork efficiently with Foundation and Swift Standard libraryUnderstand the most critical GoF patterns and use them efficientlyUse Swift 4.2 and its unique capabilities (and limitations) to implement and improve GoF patternsImprove your application architecture and optimize for maintainability and performanceWrite efficient and clean concurrent programs using futures and promises, or reactive programming techniquesUse Swift Package Manager to refactor your program into reusable componentsLeverage testing and other techniques for writing robust codeWho this book is for This book is for intermediate developers who want to apply design patterns with Swift to structure and scale their applications. You are expected to have basic knowledge of iOS and Swift.