What is a regression (or non-regression) test?

According to the ISTQB definition, a regression test consists of testing a previously tested program, after a modification, to ensure that defects have not been introduced or discovered in unmodified parts of the software, as a result of the modifications made.

In short, a regression test is used to check that changes made to the software, website or mobile application, such as the addition of a new feature or an update, have not impacted previously existing functionality. Let's take the example of a bicycle: if the wheel is changed, a regression test would consist in checking that, despite the wheel change, the brakes still work (but there's no need to check that the bicycle pump still hooks up properly). What's the difference between regression testing and non-regression testing? Actually, there isn't any. They're exactly the same thing. We use both terms. The ISTQB, for example, prefers the term regression test.

What are the different types of regression test?

Regression and non-regression tests can be carried out in a number of ways, depending on the need or the company's resources.

Mr Suricate or how to automate your non-regression tests?

Non-regression tests have a real interest in being automated, and are in fact the tests we often recommend automating first. Why? Because they are repetitive and time-consuming. They're run every time a new feature or software update is deployed, and doing them all manually takes time, a lot of time, not to mention the fact that it requires you to do a lot of easy things, and the sequence will become tiresome and difficult. This is where the automation of regression test cases comes into its own.