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Test-Driven iOS Development with Swift 4 - Third Edition

Book Description

Use test-driven approach to develop highly-functional iOS apps with Swift 4 and Xcode 9

About This Book

  • A practical guide to writing effective, organized, and clean code that works well
  • Learn test-driven principles to help you build better-designed apps with fewer bugs
  • A comprehensive overview of the techniques available for TDD in Swift

Who This Book Is For

To get the most out of this book, you will need some prior experience with Swift application development. You may have already heard about Test-Driven Development (TDD) but you don't need any prior experience of applying it to Swift applications.

What You Will Learn

  • Implement TDD in Swift application development
  • Find bugs before you enter code using the TDD approach
  • Use TDD to build models, view controllers, and views
  • Test network code with asynchronous tests and stubs
  • Write code that is a joy to read and maintain
  • Develop functional tests to ensure the app works as planned

In Detail

Test-driven development (TDD) is a proven way to find software bugs early. Writing tests before you code improves the structure and maintainability of your apps. Using TDD, in combination with Swift 4's improved syntax, means there is no longer any excuse for writing bad code.

This book will help you understand the process of TDD and how to apply it to your apps written in Swift.

Through practical, real-world examples, you’ll learn how to implement TDD in context. You will begin with an overview of the TDD workflow and then delve into unit-testing concepts and code cycles.

You will also plan and structure your test-driven iOS app, and write tests to drive the development of view controllers and helper classes. Next, you’ll learn how to write tests for network code and explore how the test-driven approach—in combination with stubs—helps you write network code even before the backend component is finished.

Finally, the book will guide you through the next steps to becoming a testing expert by discussing integration tests, Behavior Driven Development (BDD), open source testing frameworks, and UI Tests (introduced in Xcode 9).

Style and approach

Using a step-by-step approach, you will develop an entire iOS app using TDD. During the course of the book, you will explore different strategies for writing tests for models, View Controllers, and networking code.

Downloading the example code for this book. You can download the example code files for all Packt books you have purchased from your account at http://www.PacktPub.com. If you purchased this book elsewhere, you can visit http://www.PacktPub.com/support and register to have the code file.

Table of Contents

  1. Preface
    1. What this book covers
    2. What you need for this book
    3. Who this book is for
    4. Conventions
    5. Reader feedback
    6. Customer support
      1. Downloading the example code
      2. Downloading the color images of this book
      3. Errata
      4. Piracy
      5. Questions
  2. Your First Unit Tests
    1. Building your first automatic unit test
      1. What are unit tests?
      2. Implementing a unit test example
      3. Important built-in assert functions
    2. Understanding TDD
      1. The TDD workflow - red, green, and refactor
        1. Red
        2. Green
        3. Refactor
    3. TDD in Xcode
      1. An example of TDD
        1. Red - example 1
        2. Green - example 1
        3. Refactor - example 1
        4. Red - example 2
        5. Green - example 2
        6. Refactor - example 2
        7. A recap
      2. Finding information about tests in Xcode
        1. Test Navigator
        2. Tests overview
        3. Running tests
          1. Running one specific test
          2. Running all tests in a test case
          3. Running a group of tests
        4. The setUp() and tearDown() methods
        5. Debugging tests
        6. Breakpoint that breaks on test failure
        7. The test again feature
    4. The advantages of TDD
    5. The disadvantages of TDD
    6. What to test
    7. Summary
  3. Planning and Structuring Your Test-Driven iOS App
    1. The task list view
    2. The task detail view
    3. The task input view
    4. The structure of the app
      1. The table view controller, the delegate, and the data source
      2. Table view cells
      3. The model
      4. Other view controllers
      5. The development strategy
    5. Getting started with Xcode
    6. Setting up useful Xcode behaviors for testing
      1. Useful build behaviors
      2. Testing behaviors
    7. Summary
  4. A Test-Driven Data Model
    1. Implementing the ToDoItem struct
      1. Adding a title property
      2. Adding an itemDescription property
      3. Removing a hidden source of bugs
      4. Adding a timestamp property
      5. Adding a location property
    2. Implementing the Location struct
      1. Adding a coordinate property
    3. Implementing the ItemManager class
      1. Count
      2. Adding and checking items
      3. Equatable
      4. Removing all items
      5. Ensuring uniqueness
    4. Summary
  5. A Test-Driven View Controller
    1. Implementing ItemListViewController
    2. Implementing ItemListDataProvider
      1. Conducting the first tests
      2. Fake objects
      3. Using mocks
      4. Checking and unchecking items
      5. Implementing ItemCell
    3. Implementing DetailViewController
    4. Implementing InputViewController
    5. Summary
  6. Testing Network Code
    1. Implementing tests using a web service
    2. Implementing a login request
    3. Handling errors
    4. Summary
  7. Putting It All Together
    1. Connecting parts
      1. The initial view controller
      2. Showing the input view
      3. Showing the detail view
    2. Serialization and deserialization
    3. Functional tests
      1. Adding a UI test target
      2. Recording and testing
    4. Summary
  8. Code Coverage
    1. Enabling code coverage
      1. Code coverage in Xcode
      2. How much code coverage is enough?
    2. Automatic deployment with fastlane
      1. Installing fastlane
      2. Setting up
    3. Summary
  9. Where to Go from Here
    1. What you have learned so far
    2. Integration tests
    3. UI tests
    4. Behavior-Driven Development
    5. TDD in existing projects
    6. Generating mocks with Sourcery
    7. More information about TDD
    8. Summary