I have ever tried to use JUnit4 in Katalon Studio.
Using this technique, I could write a JUnit4-based Groovy class under the Include/scripts/groovy
directory with a lot of @Test
annotation, and executed that test class by invoking a Test Cases/xxxxTestRunner
. I used JUnit4 to test my Custom Keyword classes. I got a success. This works fine. However, it produces poor execution reports, which is a mere StackTrace of exception thrown, which would not satisfy you.
You might be able to develop a similar library that enable you to run TestNG in Katalon Studio. The jar of TestNG is bundled in the Katalon Studio’s distributable archive.
This approach (using JUnit and TestNG in Katalon Studio) is possible but techinically complecated. I do not recommend this approach for ordinary UI-testers unless they have good reason.