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

Implementing the delegate of a table view

When the user selects a to-do item in the list of items, the details of the to-do item should be shown in a dedicated view. We will implement the actual navigation between the different views of the app in Chapter 11, Easy Navigation with Coordinators. In this section, we will implement the required code in ToDoItemsListViewController.

Follow these steps to prepare ToDoItemsListViewController for navigation to the detail view:

  1. Let's assume we already have a delegate that will provide a method the view controller can call. Add the following test method to ToDoItemsListViewControllerTests:
    // ToDoItemsListViewControllerTests.swift
    func test_didSelectCellAt_shouldCallDelegate() throws {
      let delegateMock = 
        ToDoItemsListViewControllerProtocolMock()
    }

Xcode tells us that it cannot find the ToDoItemsListViewControllerProtocolMock type. This type is meant to be a mock object for the real delegate...