How to Conduct an Effective API Regression Testing with Minimum Resources Spent

Regression testing is crucial for high-quality end results, yet it requires a large number of resources. For many business owners, this might be daunting.

In software development, regression testing composes nearly 80% of the testing costs. How do we optimize expenses for regression testing without compromising product quality? That’s the crucial question.

In this article, I will explain regression testing’s meaning, why it is important for businesses, how to accelerate it, and which tools to use to compensate for the lengthy process. So, without further ado, let’s move on to regression testing and its specifics.

What is Regression Testing?

Before delving into the specifics of regression software testing, let’s define regression testing first and then gain a deeper understanding of the concept.

Regression testing is a method of re-running functional and non-functional tests to ensure that previously developed functionality performs as expected after new changes are introduced.

Imagine software development as a process of continuous improvement and expansion of basic functionality. With each new iteration, the functionality expands and potentially influences the basic functionality. This is why regression testing is done: to ensure that the influence is either positive or minimal and doesn’t disrupt the app’s expected performance.

Each introduced API leads to the basic functionality being re-tested. In the graph below, you can see how regression testing is performed alongside new feature testing. With each new version (V in the graph), new functionality is added (F in the graph); this signifies the transition of an old functionality into a scope of regression testing, a.k.a. potentially affected functionality.

This is also why it’s so resource-consuming compared to other testing methods, such as penetration testing for security or integration testing, which is typically performed when a new API is integrated.

Regression Testing vs Retesting

Regression testing and retesting are concepts that often go hand in hand and can sometimes be confused. So, let’s examine them side by side.

Regression testing is meant to identify whether new components of the system affect previously existing ones.

While

Retesting is used to ensure that components that failed the previous tests are fixed and ready to be used.

Regression testing is usually directed at the whole application, while retesting targets its altered specific components. The following table demonstrates the difference.

So, regression testing and retesting are both equally important parts of the quality assurance process; however, this section clearly highlights the distinction between them.

Now, let’s talk about the reasons business owners should consider conducting regression testing regardless of their product’s specifications or aims.

Why Businesses Need Regression Testing

Unexpected software failures can lead to downtime, data loss, and a negative user experience. This is why regression testing in software testing, despite being resource-consuming, might bring more business benefits to the company in the long run.

Every business needs regression testing to prevent costly disruptions and ensure product quality.

In a broader scope, business owners need their teams to perform regression testing for the following reasons:

1. Workflow stability. Stable performance can only be achieved if new functionality or updates don’t interfere with existing functionality, which regression testing can aid with.
2. Risk mitigation. Regression testing can detect faulty code at early stages, therefore, allowing it to be fixed before permanent changes are introduced or released.
3. Cost-efficiency. Automation is the key to regression testing. Since it reuses automated test cases, it can accelerate the process and make fault detection more cost-efficient.
4. Elimination of bottlenecks. With regression testing, your team can detect imperfections in the software early on and fix them before they impact an app’s workflow.
5. Costs optimization. When imperfections are identified early, it will take less time and effort to fix them. This, in turn, can prove to be cost-effective.

Overall, regression testing in software testing is important and efficient and can yield significant benefits despite being time-consuming. If possible, it could be accelerated, creating a bigger business impact.

But before we figure out how to accelerate the process, let’s examine and define the regression testing process.

Regression Testing Process

The regression testing process is not too complex to understand. In many ways, it follows the standard QA practice.

So, let’s take a closer look at what the API regression testing process looks like:

1. Identify source code changes. At this step, QA experts identify modifications made to the source code, such as new features, code refactoring or enhancements, etc.
2. Prioritize identified changes and product requirements. The next step is to determine the severity of the impact and how these changes affect the product’s expected functionality. After this, the QA team usually assesses the risks associated with these changes, which will later help prioritize them.
3. Select test cases to re-run. Based on the identified changes and their expected impact, all test cases covering the functionality directly affected by the changes will be approved for a re-run.
4. Consider test scenarios. As a standard procedure, the QA team develops different scenarios to assess the app’s behavior with new changes.
5. Categorize test cases. This stage includes categorizing test cases based on different aspects that determine them, such as functionality or type. It also helps with prioritizing what comes next.
6. Prioritize test cases. The test cases are prioritized based on two critical factors: risk and business impact. Those with the most crucial impact and higher risk can be re-run first.
7. Schedule and execute test cases. Finally, the team creates a software regression testing schedule that defines the order and timing of test execution.

To learn more about innovative QA services that can enhance your app’s business value, check out this web page to learn what the QA team from DashDevs offers.

The process can help you understand the basics of software regression testing in software testing and will help you see how we could accelerate it. Without further ado, let’s move to the next segment and discuss how to make regression testing less time-consuming.

How to Accelerate Regression Testing

Acceleration of API regression testing can lead to enhancement of the software development process as it will significantly improve the time spent on the whole QA process and accelerate time-to-market and SDLC in general.

In this section, I want to expand on how to accelerate regression testing in such a way that will maintain your QA process integrity yet enhance resource consumption.

Test Scope and Prioritization

Test scope defines the specific areas of your software that will be tested during regression, while prioritization ensures that the most critical areas are given priority in the testing process.

So, when creating a test scope, identify and prioritize the most critical areas of the application that might be impacted by recent changes. Your team can do so by generating ranks for each test case. Here’s the formula:

The rank of a test case = importance value + frequency value.

In this case, importance value is the importance of the chosen functionality for business from 1 to 5 (ascending).

• 1 are edge cases that occur only in rare situations.
• 2 is for minor app logic features.
• 3 and 4 are for the logic core of the app.
• 5 is for features that, if malfunctioned, might lead to critical download decline, income loss, or major failure.

The frequency value in this formula is the number of times and users who use the affected functionality, ranging from 1 to 5 (ascending).

• 1 is for features used not often by a small number of users.
• 2 is for features used by a small number of users but quite often.
• 3 is for features used by many users but not often.
• 4 is for features used by many users most of the time.
• 5 is for features used by all users.

This way, you can sort your test cases based on their importance rank, where only 10% will need your immediate attention. This can save time for your business drastically, helping you concentrate the efforts on that functionality that will directly impact your business.

Regression testing of an iOS application: A success story

Challenge: With one of the case studies I’ve previously worked on, we had quite tight deadlines. In the preparation for release, we noticed that there was not enough QA documentation to run regression tests quickly.

Solution: This is when I thought of using this method to prioritize test cases. At first, I focused on tests that had shown to be faulty in previous iterations and had a crucial impact on the software’s productivity, and later on, I moved to the features that were affected and expected to be used by most of the users.

Results: This approach to regression testing allowed the team to prioritize what we needed at the time and release the fully functional application within the scope of tight deadlines.

Automation

Test automation involves using software tools to execute regression test cases repeatedly without manual intervention.

If you learn how to automate API testing regression, you can significantly decrease the number of manual errors or inconsistencies and execute a large number of test cases in a shorter time. It’s been studied that automation can reduce testing time by 40% and effort by 60%.

If you are interested in QA automation services, the DashDevs team offers this service.

You can achieve this with automated regression testing if you follow these tips:

1. Nitpick on the tests to automate. For automation, use only cases that are frequently executed or repetitive. If your test cases are stable, you will eventually render higher ROI from this investment, as automation would yield more predictable results.
2. Build a strong framework for automation. Establish solid testing principles, and create reliable documentation, including mainable test scripts. This will help ensure stability and consistent future improvement.
3. Improve and iterate. When building a framework, you should not forget about iterating. Review the principles and their correspondence with testing efficiency to ensure that your automation strategy is relevant.
4. Select the right tools. Choose robust and reliable test automation tools that are suitable for your specific needs and technology stack.

Tools, arguably, might be one of the most important parts of automation practices. They can ensure that you have everything tackled in the tech aspect of testing.

The Best Tools for Regression Testing

When choosing the best regression testing tools for API regression testing, pay attention to the key features they provide. Connect their capabilities with your requirements, and review which ones suit you the most. In this segment, I will review the most popular ones that I’ve encountered in my work.

Read this article on software quality control to learn more about quality assurance and different approaches to it.

Postman

Postman is an API platform that simplifies the entire API lifecycle, including the testing process. It excels at API-centric regression software testing, which would help your team ensure that your APIs function correctly after code alterations.

With Postman, your QA team could create, manage, and run test collections that include documentation and tests. Its data-driven testing can ensure fewer manual mistakes and improved efficiency.

This tool also has seamless opportunities for CI/CD pipeline integrations, which would enable your team to run tests automatically on a daily basis. This is one way you can ensure minimum manual intervention and, therefore, less resources and time spent on regression tests.

Selenium

Selenium is an open-source framework for web application testing that includes. It’s cost-effective and already makes software regression testing less resource-intensive.

This tool might be one of the best options for creating a cross-platform solution, as it supports different browsers and enables testing for various platforms. To further support this argument, Selenium also combines multiple programming languages, which can also make the development more versatile.

However, it has limited support for non-web applications and won’t be as useful for anyone creating a mobile app. Due to the tool’s complexity, setting up a Selenium framework might be more time-consuming than Postman.

Playwright

Playwright is an open-source test automation library developed by Microsoft.

Like Selenium, Playwright supports multiple languages and cross-browser development, which might also support cross-platform development. Unlike the above described, however, Playwright also supports mobile browsers on both real devices and emulators.

It also has certain features that set it apart from competitors, including:

1. Auto-waiting for elements to be visible and clickable reduces flakiness.
2. Network interception allows mocking or stubbing network requests for better control over test environments.
3. Trace viewer provides a detailed record of test execution, aiding in debugging.

Like Postman, it also has a seamless CI/CD pipeline integration. However, since it is relatively new, the community and ecosystem would be smaller. It’s also more complex than Postman, so it would require more time to set up.

To summarise all of it, here’s a table that compares these tools:

To summarise all the above, you should consider the needs of your project. If you are looking for API testing, which is the most often performed for fintech applications, use Postman. Meanwhile, Selenium and Playwright are a good fit for web apps. You can always contact DashDevs if choosing a tool proves to be complex.

Final Thoughts

Overall, API regression testing is crucial to ensure that each new update yields more success for your project and doesn’t harm it. It’s mandatory for every software development as it is the only way to avoid being blinded by updates and maintain consistent quality marks.

If you are interested in any opportunity to achieve better results with QA, you should take note of the DashDevs team. We have over 15 years of experience and 500+ completed projects, so we will most certainly help you navigate through regression testing. Let’s discuss it!