Book Image

Test-Driven iOS Development with Swift

By : Dr. Dominik Hauser
Book Image

Test-Driven iOS Development with Swift

By: Dr. Dominik Hauser

Overview of this book

Test-driven development (TDD) is a proven way to find software bugs early. Writing tests before your code improves the structure and maintainability of your app. Test-Driven iOS Development with Swift will help you understand the process of TDD and how it impacts your applications written in Swift. Through practical, real-world examples, you’ll start seeing how to implement TDD in context. We will begin with an overview of your TDD workflow and then deep-dive into unit testing concepts and code cycles. We will showcase the workings of functional tests, which will help you improve the user interface. Finally, you will learn about automating deployments and continuous integration to run an environment.
Table of Contents (15 chapters)
Test-Driven iOS Development with Swift
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Enabling code coverage


Measuring the code coverage of our tests gives us a feeling of completeness about our test suite. When following the TDD workflow, as we don't write any code without a failing test, the code coverage of our project should be very high. We don't expect it to be 100%, meaning that all the code paths are executed in the tests because the static analyzer forces us to write code that we don't expect to be executed. For example, in the code we wrote, we often used guard to make sure that the value we wanted to access was not nil. We could have written tests for a case where the value was nil. But in my opinion, these tests give no additional value.

Nevertheless, we will examine the parts of the project without code coverage and discuss whether we need to add tests to cover them.

Code coverage in Xcode

Xcode has added native support for the measurement of code coverage of tests with version 7. To enable it, select Edit Scheme... in the Scheme selector in Xcode:

In the following...