Regression testing is a verification method to check that a change or an update in the code has not led to emergence of new bugs or re-emergence of the older ones.

For example, if product X confirms an order and notifies the confirmation of the order to the buyer and the seller. If a bug causes some issues in the confirmation mails sent to the buyers, and with some changes are made in the code, regression testing is done to see that the new changes have solved the previous problem, and also the other part of the product is checked to ensure it works as smoothly as before.

You now understand why regression testing services are vital?

Let’s dive deep and understand all the important aspects of regression testing.

Regression Testing Explained Briefly

Regression testing does not rely on any programming language such as C++, C#, Java or others, rather it is a way to check the product after any changes or updates are introduced in the code. It checks whether any modifications have altered the current functioning of the product.

Regression testing ensures that the bug is fixed and this has not led to emergence or re-emergence of new or old bugs.

When to Avail Regression Testing Services?

The right stage to perform regression testing is after verifying changes or the new functionality implemented in the product. However, this is a general scenario, and there are exceptions to this:

–       For releases that take months to complete, regression testing must be a part of the daily cycle.

–       For weekly releases, regression testing can be done after functional testing is over.

Regression testing is a type of retesting, however, the reason for a retest can be anything, say if you started with a test the previous day, but could not complete it, so the next day you again perform the test. But in case of regression testing, the core reason to perform it remains the same – checking the code after any alterations for emergence or re-emergence of bugs. Any type of change whether related to the code, design, hardware or anything that rules the framework of the product means regression testing services are needed.

Kinds of Regression Testing

Here are the types of regression tests:

–   Unit Regression

In the unit testing phase, the code is tested in isolation and this is called unit regression. In these tests, any dependencies on the unit are blocked, and then the tests are done so the units can be tested without any discrepancy.

–   Partial Regression

These tests are done to ensure that the code works seamlessly after the changes have been done in the code.

–   Complete Regression

Complete regression tests are performed when an alteration in the code is done on several modules of the code, and also when the impact of a change on the other modules is uncertain. In this case, the whole product is checked for any alterations in functioning because of the new changes.

How are Regression Checks Done?

–   Redo the tests conducted previously.

–   Compare the previous results and the current results.

This is a process that goes on in continuity and is performed at various stages in the lifecycle of software testing.

An excellent practice is to conduct regression testing after Sanity or Smoke Testing, and at the end of Functional Testing for a short release.

A perfect test plan is a base for effective regression tests. This plan states the regression testing strategies and the exit parameters. Also, performance testing is a crucial part of this test as it ensures that the system performance is not altered by any new changes.

Final Words

Regression testing services are crucial in the lifecycle of software testing as they make sure no new changes affect the previous functionality of the product. It also checks that the new alterations in the code do not lead to occurrence or recurrence of any new or old bugs respectively.