What is Regression testing ?

About regression testing .

Regression testing is an integral part of the software development life cycle

What is Regression testing?

Regression testing is a type of software testing conducted after a code update to ensure that the update introduced no new bugs

Why Regression Testing is important?

Think about how often your most frequently used applications update. Now imagine that each time these updates occurred, key functionalities failed. Why is regression testing important? Because it allows developers to make continuous improvements to applications without disturbing the end user’s experience. In addition to validating the functionality of new code, it ensures its compatibility with existing features.

When should regression testing be done?

The next question in line after “why is regression testing important?” is typically “when should I use it?” Utility varies from project to project, but regression testing is generally the most useful in the following scenarios:

• Implementing new code
• Making changes to old code
• When an application is ported to another platform
• Addressing program bugs
• Fixing performance issues

How to Regression Testing Perform

1 Build your regression suite

To do regression testing, a tester must build a regression suite. A regression suite is essentially an overview of the different functionalities that your software consists of, and that you’ll therefore want to test. These are also called test scenarios.

Building a regression test suite doesn’t necessarily require a lot of work. The suite can be created from the existing test cases – functional tests, integration tests, unit tests, etc. – that you probably already have. Anything that has previously successfully verified that the software functions as intended can be used in your regression suite.

2. Select a regression testing approach

How much of your testing should be automated? The answer to this question largely depends on your approach to testing; will you write all your test cases upfront and stick rigidly to these when testing, or will you take a more exploratory approach where your testing is more free and unstructured?

The approach you choose should ideally fall somewhere on a spectrum between the two.

3. Select your test cases for the regression suite

As a starting point, if you haven’t built your test suite before and you need help figuring out where to start, it can be useful to select your test cases based on the importance of functionality .

4. Decide the frequency of your test runs

Once you’ve built your regression testing suite, you need to decide how often you want the regression tests to run.