Avi Tsadok - XCTest Framework for UI and Unit Testing

Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the books product page, located at www.apress.com/978-1-4842-6381-5 . For more detailed information, please visit http://www.apress.com/source-code .

If you dont like unit testing your product, most likely your customers wont like to test it either.

Anonymous

Software testing is a complementary process to your development flow. It may be the only way to monitor your work and your project over time, and as a result, it has a positive impact on how your project is built and how your code is written.

This book takes you from the very beginning of what software testing is, how to set up an excellent infrastructure, how to write a great, clean, testable code, and of course how to test your code in many ways and techniques.

Although its possible to read this book in chronological order, you dont have to follow that rule. There are some theoretical chapters that I recommend you start with, and for the practical chapters part, you can read them in any order you want.

Even if you have a lot of experience with writing tests, I believe you can find new useful tips and exciting techniques to leverage your coding and testing skills.

There are plenty of code samples and examples throughout the book you can try yourself and even add them to your existing tests (if you have some).

Testing is a process aimed to retrieve information about the quality of an app, a feature, or a function. Developers and QA testers manage testing by running a program that examines your app code and decides if it's ready for production or if it's broken.

The testing process can investigate your app in several ways product requirements, edge cases, performance, memory, different screens/devices, or integrations. In many cases, testing is a part of a continuous deployment service or integration, where it plays a significant role in an automatic deployment process to the App Store or TestFlight.

If you havent written tests yet, the test target may look like an alien to you. To be aligned, take a look at the marked part in Figure .

Figure 1-1

Test targets in Xcode project

Those are your projects test targets, and their primary mission is to help you monitor your code quality and performance. This is done using test functions when each of them is responsible for a specific use case .

A test function might look something like this:

func testPrimeNumberFunction() {

// arrange

let number = 7

// act

let result = MathService().isPrimeFunction(number: number)

// assert

XCTAssertTrue(result)

}

The preceding code is an example of a simple test function that checks if a function called isPrimeFunction() is working correctly.

Note

Although all the code examples in this book are written in Swift, you can write tests in Objective-C as well. But Im sure youll be able to understand most of my examples even if your Swift knowledge is poor.

As iOS developers , we write functions every day. Some of them are very simple, but some are incredibly complex. How can we make sure they perform as expected in different cases? Not only that how can we make sure we dont break them over time as our project gets bigger?