Book Image

Test-Driven iOS Development with Swift - Fourth Edition

By : Dr. Dominik Hauser
5 (1)
Book Image

Test-Driven iOS Development with Swift - Fourth Edition

5 (1)
By: Dr. Dominik Hauser

Overview of this book

Test-driven development (TDD) is a proven way to find software bugs earlier on in software development. Writing tests before you code improves the structure and maintainability of your apps, and so using TDD in combination with Swift 5.5's improved syntax leaves you with no excuse for writing bad code. Developers working with iOS will be able to put their knowledge to work with this practical guide to TDD in iOS. This book will help you grasp the fundamentals and show you how to run TDD with Xcode. You'll learn how to test network code, navigate between different parts of the app, run asynchronous tests, and much more. Using practical, real-world examples, you'll begin with an overview of the TDD workflow and get to grips with unit testing concepts and code cycles. You'll then develop an entire iOS app using TDD while exploring different strategies for writing tests for models, view controllers, and networking code. Additionally, you'll explore how to test the user interface and business logic of iOS apps and even write tests for the network layer of the sample app. By the end of this TDD book, you'll be able to implement TDD methodologies comfortably in your day-to-day development for building scalable and robust applications.
Table of Contents (17 chapters)
Section 1 –The Basics of Test-Driven iOS Development
Section 2 –The Data Model
Section 3 –Views and View Controllers
Section 4 –Networking and Navigation

Chapter 3: Test-Driven Development in Xcode

For test-driven development (TDD), we need a way to write and execute unit tests. We could write the tests into the main target of our Xcode project but that would be impractical. We would have to separate the test code from the production code somehow, and we would have to write some scripts that execute the text code and gather feedback about the results of the tests.

Fortunately, this has already been done. It all started in 1998, when the Swiss company Sen:te developed OCUnit, a testing framework for Objective-C (hence the OC prefix). OCUnit was a port of SUnit, a testing framework that Kent Beck had written for Smalltalk in 1994.

With Xcode 2.1, Apple added OCUnit to Xcode. One reason for this step was that they used it to develop Core Data at the same time that they developed Tiger, the OS with which Core Data was shipped. Bill Bumgarner, an Apple engineer, wrote this later in a blog post:

"Core Data 1.0 is not perfect...