iOS Regression Testing Tools: A Guide

As developers, we know the importance of testing our work before releasing it. 

Testing ensures that what we build does what we intended and reduces the technical debt that can arise from poor code quality. It's a crucial part of the development pipeline of the most productive teams. 

Today, we'll explore how we can take our tests to the next level with regression testing. 

In this post, we'll discuss regression testing in iOS, why it's so essential, and the best tools available. Additionally, we'll provide a brief example of a regression testing scenario and the best practices to perform it successfully.

Let's dive in. 

What Is Regression Testing?

In short, regression testing is a type of testing used to confirm that changes made to a software system have not negatively impacted its existing functionality. This process is necessary because changes to a software system, whether intended to fix bugs or add new features, can sometimes have unintended consequences and cause existing functionality to break. 

By re-running previously run tests after developers make changes, developers can verify that the changes haven't generated any regressions or negative impacts on the software. This procedure ensures that modifications to a software system don't adversely affect existing functionality, making it a crucial step in the software development cycle. 

Why Is Regression Testing Important?

The main reason why it's vital to perform regression testing when releasing new versions of a software system is to ensure that the software is stable and reliable.

As discussed above, we want to ensure that we aren't introducing bugs or errors in our work, thus introducing more technical debt and making our lives harder. 

You might think that this isn't necessary because your project is small and you can manage to test most scenarios with some basic tests. But you might not yet grasp the benefits of a robust regression testing workflow. 

Regression Testing Benefits

Here are several reasons why regression testing is essential in all project sizes and complexities: 

1. Quality assurance—Regression testing helps ensure that the software is of high quality and meets the desired level of functionality. By regularly performing regression testing, developers can identify and fix any issues that may have been introduced by changes to the system.
2. Cost-effectiveness—Fixing issues after a software system has been released can be costly and time-consuming. So, developers can save time and money in the long run by identifying and fixing issues during the development process through regression testing.
3. User satisfaction—If a software system has issues or bugs, it can lead to poor user experience and dissatisfaction. However, with regression testing, developers can confirm that their software is stable and reliable, leading to a better user experience.
4. Maintaining trust—If a software system is unreliable or prone to issues, it can lead to a lack of confidence from users and stakeholders. That's why it's so necessary to regularly conduct regression testing—for developers to demonstrate their commitment to maintaining the quality and reliability of their software, which can help build and maintain trust.

Now that we understand the importance of regression testing, let's discuss some of the most popular tools in iOS. 

Popular Regression Testing Tools for iOS

In the case of iOS development, several tools are available to help developers perform regression testing on their apps. 

1. XCTest

One popular tool for iOS regression testing is Apple's XCTest framework. XCTest is a unit testing framework included with the XCode development environment, allowing developers to write and run tests for their iOS apps. It supports both unit tests, which test individual functions or methods, and UI tests, which test the app's user interface. 

With XCTest, developers can create tests that simulate user interactions with the app, such as tapping buttons or entering text, and verify that the app responds as expected. Additionally, XCTest supports asynchronous testing, allowing developers to test multi-threaded code and ensure it works correctly.

You can find an example in this post. 

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2. Calabash

Calabash is an open-source framework that allows developers to write and run automated acceptance tests for iOS and Android apps. It uses Cucumber, a behavior-driven development (BDD) tool, to define test scenarios in natural language, making it easy for developers and nontechnical stakeholders to understand and collaborate on test cases. 

One of the key benefits of Calabash is its ability to test apps on real devices as well as on emulators and simulators. This allows developers to test their apps in various environments and get a more accurate representation of how they'll perform on real devices. 

3. Appium

Appium is an open-source, cross-platform test automation tool that allows developers to write tests for iOS and Android apps using a variety of programming languages, including Java, Python, and Ruby. 

Much like Calabash, Appium uses the BDD approach, allowing developers to define test scenarios in natural language. It also supports a wide range of testing types, including unit testing, functional testing, and performance testing.

One of Appium's main advantages is its capacity to test native, hybrid, and web apps, making it a flexible solution for various testing requirements. 

Commercial Tools

In addition to these free, open-source tools, several commercial tools are also available for iOS regression testing. 

Here are some examples: 

1. Waldo

Waldo is an automation testing platform that allows anyone on your team to create reliable, automated mobile tests. 

To speed up the QA testing procedure, Waldo automatically runs your test suite after you upload a new application build and tells you if any bugs, crashes, or UI issues are discovered. 

Waldo can also automate regression testing on iOS apps by allowing developers to create and run tests that simulate user interactions with the app, such as tapping buttons or entering text, and verify that the app responds as expected. 

More on them later. 

2. TestComplete

Another example is TestComplete, a test automation tool that allows developers to create and run tests for iOS and Android apps.

TestComplete supports a wide range of testing types, including unit testing, functional testing, and performance testing, and it provides various tools for managing and organizing test cases.

It also offers integration with popular development tools and environments, such as Jenkins and Visual Studio, making it easy for developers to integrate regression testing into their workflow. 

3. Perfecto Mobile

Perfecto Mobile is a cloud-based testing platform that allows developers to test their iOS and Android apps on various devices and operating systems. It provides tools for managing test cases and tracking defects, as well as real-time analytics and reporting capabilities. 

Perfecto Mobile also offers various testing services, including manual testing, automated testing, and performance testing, making it a comprehensive solution for regression testing. 

Regression Testing Best Practices

When developing a robust regression testing pipeline, it's essential to follow certain best practices. This will ensure that your test gives you an accurate and valid representation of the reality of your app. 

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Here are some best practices for regression testing: 

1. Clearly Define the Scope of the Regression Tests

It's essential to determine the specific areas of the software system that will be tested as part of the regression testing process. This helps ensure that the tests are focused and relevant, and it can also help reduce the time and effort required to perform the tests. 

2. Prioritize Tests Based on Risk and Impact

Not all tests are created equal, and it's crucial to prioritize the tests based on their potential risk and impact. Tests that have a higher risk of breaking existing functionality or that have a significant effect on the software system should be given higher priority. 

3. Regularly Review and Update Tests

As the software system evolves, it's essential to periodically review and update the regression tests to ensure they're still relevant and practical. This can help ensure that the tests cover the software system's most important areas and provide valuable feedback. 

4. Use Automated Testing Tools

Automated testing tools can significantly improve the efficiency and effectiveness of regression testing. By using automated tools, developers can re-run tests quickly and consistently, and they can also be used to test large and complex software systems. 

5. Leverage Test Cases and Scripts

Using test cases and scripts can help ensure that the regression tests are thorough and consistent. Test cases and scripts should be well-documented and easy to understand, and they should cover a wide range of scenarios and conditions. 

6. Use Real Devices for Testing When Possible

Testing on real devices is crucial because it provides a more accurate representation of how the software will perform in the real world. It's also essential to test on a variety of different devices and operating systems to ensure that the software is compatible and functions correctly on various hardware and software configurations. 

Following these best practices can help ensure that the regression testing process is efficient, effective, and valuable for maintaining the quality and reliability of the software system. 

Regression Test Scenario

Now, let's consider a possible scenario to implement regression testing with a tool like Waldo. 

Imagine you're working on an iOS app that allows users to create and share lists of their favorite songs. This app has a feature that allows users to search for songs by artist, album, or title. 

Your manager is asking you to make some changes to the app's search feature, and you want to confirm that the changes haven't negatively impacted the app's existing functionality. 

To perform regression testing on the app using Waldo, you could use the tool to create a set of tests that cover the various search scenarios and conditions. 

Since Waldo allows developers to define tests using natural language, you could quickly build and run a test workflow on a simulator or actual device to see if the app behaves correctly after the changes. 

If the tests pass, it indicates that the changes have not negatively impacted the app's search feature, and you can proceed with further testing and development. Conversely, if the tests fail, it indicates that there may be an issue with the changes, and you can investigate and fix the problem before continuing. 

Conclusion

This is just one example of how you can conduct regression testing in iOS development using Waldo. By regularly performing regression testing with Waldo, developers can ensure that their apps are stable and maintain their desired level of quality, leading to a better user experience.