Regression testing comes under which type of testing?

Regression testing comes under Functional testing

Regression testing becomes a critical step in the SDLC for ensuring the stability of an application. It checks that the software initially designed and built will remain effective after modification or integration with other software. This type of testing is also called functional testing but can be extended into non-functional testing if the tester wants to check either the system performance or any other feature. This paper attempts to describe the importance of regression testing by first defining what regression testing is, its goals, regression testing types, methodologies, its difficulties, and its place in the overall realm of software testing.

What is Regression Testing?

It is a testing type done to verify if the recent changes in the code base have caused problems with the application’s functionality. Whenever software changes; whether through bug correction, integration of new features, or optimization of its performances there will always be a probability of inducing errors in the already functioning part of the software. Such mistakes may probably introduce faults to modify the functionality of erroneous functions, interfere with the natural use of the interface, or negatively affect the efficiency of operations performed by the system; this makes regression testing vital.

It is not only used to confirm that the new functionality is okay; it is used to determine whether or not the entire application is okay after changes have been implemented. Thus, regression testing offers a consistent trend within change-oriented software, thereby developing reliability and superior quality.

Why is Regression Testing Important?

The primary objective of regression testing is to identify any defects that may have been introduced to the applications/ code unintentionally as the code base was being updated. Without this testing, applications may deteriorate in quality, resulting in:

1. Increased Defects: The growth of new code may interfere with the old one at times this may lead to the creation of more bugs that may harm the User Interface.
2. Reduced Confidence: When there is no regression testing, it will be done to a lesser extent because there will be uncertainties whether the changes will affect the system as a whole, by the developers or testers involved.
3. High Risk of Failures: Most of the systems that are tested nearly on a daily basis because of new updates and setup, need regression testing to reduce the chances of system failure, system breakdown, or challenge functional reliability of a system substantially.

Regression Testing reduces these risks since it checks the previous operations and functionalities hence confirming whether they were affected by the new changes.

Regression Testing and Functional Testing

Regeneration testing is categorized under functional testing, an aspect of software testing that checks if a particular system delivers results in conformance with the specifications offered. It concentrates on proving the accuracy or otherwise of an application by comparing the outcome that was anticipated with the result that was obtained.

• Integration (testing of modules or single units grouped in the software).

• Integration testing where the testing is done on two or more components of the software product.

• Integration testing (of the system integrant components),

• Re-testing (testing to verify that previous working functions are not affected by a new change). It focuses on verifying the correctness of an application by comparing the expected output with the actual outcome. Functional testing encompasses several subtypes, including:

• Unit testing (testing individual components or functions),
• Integration testing (testing combinations of components),
• System testing (testing the complete system), and
• Regression testing (testing to ensure changes haven’t negatively affected previously working features).

It is for this reason that regression testing is nearly always coupled with functional testing. Nonetheless, regression testing sometimes falls under nonfunctional testing especially when testing system performance, or the ability to handle loading or usability among other things after modification.

Types of Regression Testing

There are various approaches to conducting regression testing, which can be divided into the following types:

1. Corrective Regression Testing: This type of regression testing is done when there has been no change in the source code of the product but the testing team wishes to retest the cases to check the functionality of the system. It is usually done after fixing bugs.
2. Progressive Regression Testing: The regression testing is carried out progressively when the standalone software has gone through improvements or changes. Zelkowitz’s test cases are meant to test new functionality as well as old functionality that has not been altered.
3. Selective Regression Testing: Here regression testing is done selectively, therefore it means that re-running only selected test cases is done. These test cases are selected based on the parts of the system that are prone to impact due to the recent changes.
4. Complete Regression Testing: This is the most exhaustive type of regression testing in which all the test case in the suite is run. Testing is often performed when there are many modifications to the code, for instance at the intervals between the version numbers.
5. Partial Regression Testing: In partial regression testing, only the modules or functionalities that have been changed with new code or functions are tested and not otherwise. The method should be used because of its efficiency, as well as the fact that it maintains the stability of the program while making the amendments.

Automation in Regression Testing

In particular, regression testing is an iterative process, and this characteristic predetermines its automation. Re-creating test cases for every new release or update might be very cumbersome and tiring, time-consuming not to mention the number of errors that are likely to result from the process, especially in big projects where there are frequent updates. Selenium, playwright,t, or test NG are a few of the test automation tools that help the team run test cases repeatedly. In this way, the run time of these test cases can be automated once they have been created, and can be run at any time without re-creation, which greatly increases the efficiency and speed of regression testing.

Automated regression testing ensures:

• Quick feedback: More importantly, automated tests can be executed during the CI/CD process, to get feedback quickly about changed code.
• Cost-effectiveness: Indeed, the establishment of automation demands a little time and money, but the time for manual testing be saved in the future.
• Higher coverage: Validation through automation enables the running of a larger number of test cases as compared to the validation by testers manually; therefore enhances the range of tests…

Regression testing is a tough nut to crack and here are some of the challenges that impinge on the whole process.

Despite its critical importance, regression testing comes with its own set of challenges, such as:

1. Time-Consuming: What was an effective testing as the number of application users increases so does the number of test cases that require retesting through manual regression testing which can be tiresome.
2. Test Case Selection: It is sometimes difficult to determine which test cases should be included in the regression suite. If too many are included, the process becomes cumbersome, including very few stands the risk of missing out on certain bugs.
3. Maintenance of Test Suites: If new features are added or if some features are modified, then test suites need to be updated time and again. This maintenance effort can end up becoming a problem if done badly.

Conclusion

Regression testing is necessary so that software systems become more stable and maintain high quality for as long as possible. It is useful in the identification of problems that might have been introduced by new changes without proper detection. Since software changes are inevitable this implies that the task of regression testing becomes even more important as designs become complex and intricate. It offers such a possibility that allows the developers to update the software to the extent of enhancing the general trust in the system execution. Due to the high efficiency of its usage for catching possible problems in the developing process, regression testing is a widespread and essential factor of reliable software deployment.