Book Image

Test-Driven iOS Development with Swift - Fourth Edition

By : Dr. Dominik Hauser
Book Image

Test-Driven iOS Development with Swift - Fourth Edition

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

Mocking CLGeoCoder

CLGeoCoder is a class provided by Apple that helps you to get coordinates from an address string and vice versa. The methods in CLGeoCoder are based on completion closures. In this chapter, we will explore how to mock and test such methods.

Cleaning your project

Before we write the first test for this chapter, let's clean up the project a bit. Add sections in the project navigator and move the files to those sections according to your structure scheme. For inspiration, here is the structure I use for the main target:

Figure 10.1 – Adding structure in the project navigator

Your structure can be completely different. Use the structure you usually use in iOS projects. Also, add a similar structure to the files in the test target.

When you add new files to the project, you have to choose the correct folder depending on the structure you applied.

Preparations for the tests

Before we can write tests for the APIClient...