Automated Regression Testing

Anushree Chatterjee

Let’s say that you’re eagerly awaiting a new feature for your mobile app. The feature arrives, and with great enthusiasm, you upgrade to this version of the app. Unfortunately, this new version causes issues with another feature, killing the experience. Imagine the ramifications of such an occurrence – disgruntled users, inflow of complaints, reduced user base, financial losses, and a bad reputation. Sounds terrible, doesn’t it?

In the world of software development, regression testing is the remedy to this problem. But doing it manually, especially under timeline pressures, will be laborious. Hence, you need automation to take care of some, if not all, of regression testing.

Let’s understand automated regression testing better.

What is Regression Testing?

Think of testing as checking two things:

• New features and avenues
• Existing system

Regression testing helps with the latter. It ensures new changes or updates to an app don’t break or negatively impact its existing features.

For example, if developers add a new feature to an app, regression testing ensures that nothing in the app that worked before is now broken or malfunctioning due to the new change.

Read more about regression testing over here – What is Regression Testing?

Approaches to Regression Testing

There are several different approaches to performing regression testing, depending on the project’s needs and the software being tested.

Retest All (Full Regression Testing)

This approach involves running all the test cases every time a change is made to the software, regardless of which part was changed. This ensures that every feature is tested to see if anything has broken.

When to Use: This approach is useful when you’re unsure which part of the software might have been affected by the changes or when you’re dealing with a major update or a completely new version of the software.

Example: After a major release of a mobile app, you might retest all features, such as login, payments, and notifications, to make sure everything works.

Selective Regression Testing

In this approach, instead of testing everything, you choose a subset of test cases to run based on the changes made to the software. You focus on the areas that were modified or are most likely to be affected by the change.

When to Use: This is a good approach when you have a large system with lots of features, and it’s impractical to test everything every time. It’s often used when the changes are isolated to specific areas.

Example: If you add a new feature to the payment system, you only run tests for the payment and checkout areas rather than testing the entire app.

Test Case Prioritization

This approach involves prioritizing the test cases based on which ones are the most important or critical to the application’s core functionality. You run the most important tests first and, if needed, run others later.

When to Use: This approach is helpful when you have limited time to run tests. It helps you focus on the most vital parts of the software first, ensuring that the most important features work before checking the less important ones.

Example: For an e-commerce website, you would prioritize tests related to user login, product purchase, and payment, as these are critical to the business.

Hybrid Approach

The hybrid approach combines elements of the first three approaches. You might run a full set of tests periodically but focus on smaller, more targeted tests most of the time. This way, you get the benefits of thorough testing while managing time and effort.

When to Use: This approach is used when you want a balance between ensuring comprehensive testing and saving time. It’s often used in agile environments where software changes happen frequently.

Example: Running full regression tests every major release but focusing on a subset of tests for smaller updates.

Regression Testing vs. Other Types of Testing

If you look at the development cycle, there are a couple of testing types that might be used to make sure that a release is stable and does not break existing functionalities.

Read more about these different types:

• The Difference Between Regression Testing and Retesting
• Smoke Testing vs Regression Testing – Key Differences You Need to Know
• What is Smoke Testing in Software QA?
• Smoke Testing vs. Sanity Testing

Why Automate Regression Testing?

Automating regression testing means using software tools to run the tests automatically without needing someone to manually check everything. Here’s why automating regression testing is a good idea:

• Saves Time: Running the same tests over and over can take a lot of time if done manually. Automation allows you to run these tests quickly, even if there are many of them. You can test everything in a fraction of the time, which is especially helpful when changes happen frequently. This is also beneficial for releasing software faster.
• Increased Efficiency: Automation tools can run tests 24/7 without needing breaks. They also do the same steps in exactly the same way every time, which reduces the risk of human error. This makes the testing process more consistent and reliable.
• Reusability: Once you’ve created automated tests, you can reuse them anytime you make updates to the software. Instead of writing new tests for every change, you can use your existing ones, which saves time and effort in the long run.
• Faster Feedback: Automation gives you quick feedback about whether new changes are causing any problems with existing features. This helps developers catch bugs early, which is better than finding them late when they are harder to fix.
• Better Coverage: With automation, you can test more areas of the software than you could manually, especially for complex systems. Automation allows you to run tests on many different parts of the software at once to ensure that nothing is missed.
• Reduced Cost in the Long Run: While setting up automated tests can take some initial time and effort, in the long run, it saves money. You won’t need to have as many people doing repetitive testing, and you can find bugs earlier, which reduces the cost of fixing them.

Read more about this over here – Why is Automating Regression Testing so Important?

How to Automate Regression Testing?

Automating regression testing can seem like a big task, but it can be broken down into simple steps. Here’s how you can do it:

• Choose the Right Testing Tools
  First, you need to select a tool that fits your needs. The tool you choose should work well with your software, and it should support scripting (writing instructions for the test) in the language you are comfortable with.
• Identify Key Test Cases
  Not all tests need to be automated. Start by identifying the most important tests – those that check the core functionalities of your app, like logging in, making purchases, or navigating between pages. These are the tests that you’ll want to run repeatedly after each change. Read: How to Write Test Cases? (+ Detailed Examples)
• Write Test Scripts
  With the tool you’ve chosen, you’ll write test scripts. A test script is just a set of instructions that tell the tool what to check. For example, you can create a script to check if a user can log in with the correct credentials. The tool will “click” buttons, enter information, and check for expected outcomes, all automatically.
  Read more about writing test scripts:
  • Test Scenarios vs. Test Cases: Know The Difference
  • How to Write Effective Test Scripts for Automation?
  • How to Write Maintainable Test Scripts: Tips and Tricks
  • Maximize Your Test Script Quality: Coding Standards and Best Practices
• Run Tests Automatically
  After writing the scripts, you can run them automatically whenever there’s a new update or build. Most tools let you schedule tests to run on their own, which means you don’t have to manually trigger them each time.
• Monitor the Results
  Once the tests run, you’ll get a report showing which tests passed and which failed. Automated tools usually give you a clear, detailed result so you can quickly identify any issues that need attention. If something breaks, you’ll know immediately.
• Maintain and Update Test Scripts
  As your software evolves, you’ll need to update your test scripts. This means if you add new features or make changes to existing ones, you should adjust your scripts to ensure they continue to test the right things.
• Integrate into Your Development Process
  You can integrate your automated regression tests into your development process. For example, you can set up continuous integration (CI), where your automated tests run every time developers push new code to the system. This helps catch issues early and ensures that your software is always stable.
  Read more about continuous integration and testing:
  • What is Continuous Testing?
  • Continuous Integration and Testing: Best Practices
  • Continuous Integration and Continuous Testing: How to Establish?
  • Continuous Deployment with Test Automation: How to Achieve?

Regression Testing Example

Let’s walk through a real-world example of automating regression testing using a simple web application – an online store.

Scenario:

Imagine you have an online store that sells clothes. The website allows users to browse products, add them to their cart, and then complete a purchase. Your development team constantly updates the website to add new features, like adding a “Save for Later” option, changing the product filtering system, or updating the checkout process.

After each update, you want to ensure that nothing has broken on the website, especially the basic, core features that customers use regularly, like logging in, adding items to the cart, and completing a purchase.

Steps for Automating Regression Testing:

• Choose a Testing Tool:
  The first step is selecting a tool to automate the tests. Let’s say the team decides to use Selenium, which is a popular tool for automating web browsers. Selenium can interact with your website just like a user would.
• Identify Key Test Cases to Automate:
  The team identifies a few important test cases that should always work correctly after each update, such as:
  • Login: Make sure that customers can log in successfully with their credentials.
  • Add to Cart: Check that items can be added to the shopping cart.
  • Checkout: Test that customers can complete the purchase by entering payment information and confirming the order.
• Write the Test Scripts:
  The QA team writes automation scripts using Selenium. For example, a script for the login test might look like this:
  • Open the website.
  • Find the login button and click it.
  • Enter a username and password.
  • Check if the user is redirected to the homepage after logging in.
  This script will be written once and saved.
• Run the Automated Tests:
  Each time a new update or feature is added to the website, you can run these automated tests. With a tool like Selenium, the tests are executed automatically without anyone needing to manually click through the website. The tool will go through each step, just like a human would, and check if everything is working as expected.
• Check the Results:
  After running the tests, the tool will provide a report. If everything works fine, the test results will show “Pass.” If something breaks (for example, if the cart button doesn’t work after the new feature is added), the test result will show “Fail.” The development team can then investigate and fix the issue.

What Types of Test Cases Should You Automate?

While automation is powerful, you need to be wary of what you apply it to. In regression testing, if you automate test cases that change frequently because the features they test are revised regularly or go after those rare or one-time test cases, you’re wasting resources.

Here’s a list of what types of test cases you should schedule for automation

Automated Regression Testing Tools

You need tools that are easy to use, offer powerful commands, and are versatile enough to adapt to changing needs.

Here’s a simple guide to help you pick a suitable test automation tool.

Adopting AI-based tools for automation is a good way to ensure that you get the most out of automated regression testing. One very competent and effective tool in the market is testRigor. This tool uses generative AI to make system testing easy and quick. Here’s how this cloud-based tool simplifies your testing endeavors:

• Simple test creation: Test automation has never been this easy. testRigor uses generative AI to let you write test cases in plain English language. You can also use the AI feature to create fully functional tests with merely an app or test description. Here are more ways for you to create test cases in testRigor – create/generate/record test cases with testRigor. These simplistic ways make it very easy for anyone to automate regression testing.
• Negligible test maintenance: Another great capability of this tool is that it handles interactions with UI elements smartly. You don’t need to dig into the page structure and locate the UI elements. Just write how you see them on the screen, and testRigor will do the rest. For example, if you want to click on the login button, just write click “Login”. This also helps when there are small changes, like the movement of the element to a different location on the page or changes to the tags and attributes of that element. Your test case will be safe since testRigor doesn’t depend on those fragile values. This is a boon since regression test suites tend to be large, and you don’t want to invest all your time into maintaining it.
• Integration with other tools: testRigor smoothly integrates with other tools like CI/CD pipelines, databases, and more. This means that you can automatically trigger regression test suites from your CI/CD pipelines after a release. After tests are executed, the results will be sent to you over email or any other collaboration tool you integrate testRigor with.
• Powerful commands: With testRigor, you can test across platforms and browsers easily and perform different types of system tests. You can easily automate the testing of 2FA, CAPTCHA resolution, QR codes, email, phone calls, SMS, AI feature testing, visual testing, accessibility, exploratory testing, and many more.

Here’s a full list of testRigor’s features.

Automated Regression Testing Best Practices

Here are some best practices to help you get better results.

• Automate the Right Tests: Focus on automating tests that are critical and frequently used, such as logging in, adding items to the cart, and checking out. Don’t try to automate everything – keep it manageable.
• Prioritize High-Risk Areas: Focus on automating test cases for areas of the application that are high-risk, such as payment systems, security features, or core workflows.
• Start Early: Begin automating your regression tests as early as possible, even during the development process. This shouldn’t be a problem since regression testing is about validating the health of the existing system. So, even if you don’t have the newer features in hand, work on automating the older ones.
• Use Data-Driven Testing: Use different sets of data to test the same functionality (for example, test with various usernames, passwords, and payment methods).
• Use Reliable Testing Tools: Choose a tool that suits your project and team. Tools like testRigor are going to be very helpful since they let you automate a variety of tasks.
• Don’t Ignore Test Maintenance: While the choice of testing tool will greatly affect your efforts on test maintenance, don’t avoid it completely. If new features are being added to the application, keep an eye out on its impact on the existing test suite.
• Run Tests Frequently: Run automated regression tests every time the software is updated or changed (such as new features or bug fixes).
• Integrate with CI/CD: Integrate your automated regression tests into a CI/CD pipeline so that tests run automatically every time the code is updated.
• Don’t Overuse Automation: While automation is great for repeated tasks, not everything should be automated. Some tests, especially those involving complex user interactions, may be better suited for manual testing.
• Review and Refactor Tests Regularly: Periodically review your automated tests and remove or refactor outdated or redundant ones.

Final Note

You can save yourself from a lot of manual testing by simply automating regression tests. By automating them, you can run them whenever you want and as many times as you need. The results will be quicker and consistent, provided you’ve chosen an automation tool wisely.

“We spent so much time on maintenance when using Selenium, and we spend nearly zero time with maintenance using testRigor.”

Keith Powe VP Of Engineering - IDT