Importance of Regression Testing in Software Development

Introduction

The Most likely used testing type in the software testing phase is the “Regression Testing” type.
In the software development process alterations in the application can take place in different forms such as new functionality, bug fixes, integrations, functionality enhancements, interfaces, patches, etc., but to ensure the software is working properly even after merging new changes is what needs to be verified. The aim to perform regression testing is to maintain the software quality and customer satisfaction throughout the development and evolution.

Here comes a blog that amplifies the significance of regression testing in the software development process.

What is Regression Testing?

Regression testing is a type of software testing in which a practice is followed to ensure that new code changes haven’t adversely affected the existing functionality of an application. Regression testing refers to the process of re-verifying a software application to validate that new code changes haven’t induced new bugs or broken existing functionalities that were previously working as expected. This testing type can measure the quality of the software application.

Regression testing is always carried out on a new build where new changes are merged with existing functionality. In regression testing, all the edge case scenarios are covered to verify if the flow works correctly with new changes added to the software. Regression test cases are automated to save human efforts through manual regression testing.

We cannot completely automate the whole regression process, but we can cover all the User Interface scenarios and repetitive scenarios by automating it. Regression testing plays a crucial role in the software development process to achieve a successful quality product as an outcome.

Types of Regression Testing

1. Unit Regression Testing

Basically, the developer performs unit regression testing to ensure that the modification does not affect the functionality of the module where the new changes are introduced. In unit regression testing each module is validated separately to avoid unwanted bugs in the software.

The main focus of unit regression testing is to test each and every individual component of the software separately, to ensure that new changes are not affecting the flow of the software. And, to make sure each component of the application is working properly.

2. Functional Regression Testing

In functional regression testing, testers validate the overall functionality of the software application after changes are made. Functional regression testing focuses on validating the core workflow of the software development. As the name of the testing type itself defines, the application is thoroughly tested to verify if new changes are not impacting the existing functionality of the software.

Also, we check whether the new features work as intended with the existing features. Functional regression testing can help us cover the integration testing with each module. With continuous functional regression testing, we can set a benchmark so that users can continue to use the core functionalities without any interruption, regardless of the ongoing updates and modifications.

3. Selective Regression Testing

In this type, testers mainly focus on the areas that are more likely to get affected by a code change in the application. The word selective itself means that only a specific part of the software needs to be tested to check the functional flow of the application. This also helps to optimize the testing efforts by selecting only the high risk areas.

selective regression testing can be acquired by focusing mainly on the bug prone area. This testing is carried out only on the selective test cases that are most likely to be affected by the change introduced in the software, selective regression is mainly useful when there are limitations of resources and time.

4. Progressive Regression Testing

This type of testing is conducted continuously throughout the development process. In this approach, QA continuously updates the test suite with respect to the code change. This process goes hand in hand with software development. After each and every small change, tests are run to avoid defects in the early stage and to minimize the chances of regression errors.

Progressive regression testing is typically an ongoing and iterative process, ensuring that each update doesn’t negatively impact the existing functionalities of the software. It is a continuous process without any interval. With each small release, progressive testing is performed.

5. Partial Regression Testing

In partial regression testing, only the modified module or area is tested instead of rigorous testing of the whole module. It verifies that the induced changes haven’t introduced any new bugs to the existing flow of the software. In this testing type, only the targeted modules and features are focused on that are likely to be impacted by merging the updates to the software.

This testing can be carried out only when there are frequent changes and updates made in specific modules. Instead of testing the entire software, only the impacted module can be tested which will save time and cost.

6. Complete Regression Testing

In this testing type, the quality assurance team performs exhaustive testing of the entire software to ensure that recent code changes haven’t impacted the existing functionality of the application. The main goal of complete regression testing is to avoid unexpected bugs and errors caused by the modifications. In complete regression testing the entire software platform is tested to verify whether all the functionalities are working as expected.

Unlike selective and partial testing which are carried out only on specific parts of the software. This testing can be time consuming, as the whole application functionality needs to be retested after every new code change. The goal of complete regression testing is to maintain the stability and performance of the software.

Perks of Regression Testing

Let’s learn how regression testing helps to improve the software lifecycle and maintain quality. Regression testing serves numerous benefits in the software development process to ensure we get a quality outcome. It is highly considered in the software development process to continuously verify the functionality of the application with every new update. Below mentioned are some of the perks we get on performing rigorous regression testing.

1. Quality

The overall quality standards of the software can be measured based on user satisfaction, software stability, and integrity. Quality can be achieved by ensuring new changes do not impact the existing software functionality and performance. Continuous regression after every alteration improves and maintains the software stability and quality which builds confidence in the development team as we avoid unwanted bugs.

2. Early Detection of Defects

Detecting defects at an early stage will help to reduce the cost of fixing the bugs later. Re-testing the existing functionality with new changes helps us to identify and debug defects introduced by new modifications. Performing regression testing from the start phase of the software life cycle can prevent the hike of issues and lessen their impact on the software.

Detecting the defect at the early stage allows the developers to focus on specific changes, making it easier to identify the main root cause and address the issues efficiently. Early detection of bugs can not only help in maintaining stability but also help to reduce the overall software impact.

3. Cost Efficiency

Identifying the issues early helps to reduce the cost of fixing the bugs, as it becomes more expensive to fix the bug at the last stage of the development process. Regression testing reduces the count of bugs in the software. Finding defects at an early stage can prevent them from causing secondary issues, saving the costs associated with multiple bug fixes. The ability to identify issues early, reduce rework, and minimize resources can gain cost efficiency through regression testing.

4. Test Case Coverage

Test case coverage in regression testing defines what functions, features, and scenarios are covered and tested to ensure modifications have not affected the functional flow of the software. Regression testing allows exhaustive testing of the software, to make sure all impacted areas and related functionalities are thoroughly tested while covering every edge case scenario and ensuring that all the core functionalities of the software are working as expected.

5. Automation Efficiency

Automating regression test cases substantially enhances the efficiency of regression testing by automating repetitive and time-consuming test case scenarios, with improving speed, accuracy, and test case coverage. Automated regression testing becomes more efficient as manual execution time is reduced. With automation testing, we can get a better visualization of the regression test coverage through report generation. Parallel execution can be achieved through automation testing which can save plenty of time and make the process more efficient.