© 2021

Test-Driven Development in Swift

Compile Better Code with XCTest and TDD

  • Test any kind of software, simple or complicated, pure logic or interfacing, with third-party dependencies

  • Gain helpful guidance from compiler errors as from failing tests

  • Solve problems incrementally by writing only as much code as necessary


Table of contents

  1. Front Matter
    Pages i-xix
  2. Gio Lodi
    Pages 1-12
  3. Gio Lodi
    Pages 13-25
  4. Gio Lodi
    Pages 69-78
  5. Gio Lodi
    Pages 79-95
  6. Gio Lodi
    Pages 97-117
  7. Gio Lodi
    Pages 119-132
  8. Gio Lodi
    Pages 133-150
  9. Gio Lodi
    Pages 151-166
  10. Gio Lodi
    Pages 185-195
  11. Gio Lodi
    Pages 235-241
  12. Back Matter
    Pages 243-288

About this book


Leverage Swift to practice effective and efficient test-driven development (TDD) methodology. Software testing and TDD are evergreen programming concepts—yet Swift developers haven't widely adopted them. What's needed is a clear roadmap to learn and adopt TDD in the Swift world. Over the past years, Apple has invested in XCTest and Xcode's testing infrastructure, making testing a new top priority in their ecosystem. Open-source libraries such as Quick and Nimble have also reached maturity. The tools are there. This book will show you how to wield them. TDD has much more to offer than catching bugs. With this book, you’ll learn a philosophy for building software. TDD enables engineers to solve problems incrementally, writing only as much code as necessary. By decomposing big problems into small steps, you can move along at a fast pace, always making visible progress. 

Participate in the test-driven development journey by building a real iOS application and incorporating new concepts through each chapter. The book's concepts will emerge as you figure out ways to use tests to drive the solutions to the problems of each chapter. Through the TDD of a single application, you’ll be introduced to all the staples and advanced concepts of the craft, understand the trade offs each technique offers, and review an iterative process of software development. 

Test-Driven Development in Swift provides the path for a highly efficient way to make amazing apps.

You will:

  • Write tests that are easy to maintain
  • Look after an ever-growing test suite
  • Build a testing vocabulary that can be applied outside the Swift world
  • See how Swift programming enhances the TDD flow seen in dynamic languages 
  • Discover how compiler errors can provide the same helpful guidance as failing tests do


Swift iOS Compiler Dependency Injection Mocks App development programming coding networking UIViewController TDD test-driven development XCTest

Authors and affiliations

  1. 1.Mount MarthaAustralia

About the authors

Gio Lodi spent the past decade writing tests. He began with full-stack web development before moving into iOS programming and, more recently, into mobile infrastructure engineering. Ruby on Rails introduced him to the TDD world, and he fell in love with the fast-paced feedback loop. Any big problem could be decomposed in smaller and smaller parts until it got to an achievable size. Due to the lack of tools he first encountered moving into the Apple ecosystem, Gio researched and experimented with testing strategies and tools document in an ongoing project that catalogued on his blog and in talks and workshops at various industry conferences. 

Bibliographic information

  • Book Title Test-Driven Development in Swift
  • Book Subtitle Compile Better Code with XCTest and TDD
  • Authors Gio Lodi
  • DOI
  • Copyright Information Gio Lodi 2021
  • Publisher Name Apress, Berkeley, CA
  • eBook Packages Professional and Applied Computing Professional and Applied Computing (R0) Apress Access Books
  • Softcover ISBN 978-1-4842-7001-1
  • eBook ISBN 978-1-4842-7002-8
  • Edition Number 1
  • Number of Pages XIX, 288
  • Number of Illustrations 18 b/w illustrations, 0 illustrations in colour
  • Topics Apple and iOS