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)
1
Section 1 –The Basics of Test-Driven iOS Development
5
Section 2 –The Data Model
9
Section 3 –Views and View Controllers
13
Section 4 –Networking and Navigation

Checking items

In a to-do app, the user needs to be able to mark to-do items as done. This is an important feature of a to-do app because part of the reason people use such apps is the satisfying feeling when marking a to-do as done.

So, our app also needs this feature. As the process of building this app is driven by tests, we start with a new test for this feature. But before we can add the test for this feature, we need to think about how we can assert in the test that the feature works. This means we need a way to get all the to-do items that are already done. The easiest way to differentiate the done to-do items from the ones that are still to be done is with a property in the to-do item itself. This way, we can filter all the to-do items according to the value of that property.

With this plan, we can start writing the test:

  1. Add the following method to ToDoItemStoreTests.swift:
    // ToDoItemStoreTests.swift
    func test_check_shouldPublishChangeInDoneItems()
     throws ...