java - How JUnit starts

Question

I'm figuring out how JUnit works. I can't understand how it runs itself, I understand that the surefire plugin interacts with JUnit, but I don't understand how JUnit itself runs. I'm trying to understand the debug output, and came across the getRunner method, but I can't get down to it, I can't understand what kind of package com.intellij.rt.junit is. Can you help me.

Answer 1

com.intellij.rt.junit is a package of IntelliJ for its built-in runner for JUnit tests, just like Surefire is the runner when tests are run from Maven.

JUnit itself also contains a basic commandline runner. For JUnit 5, see Console Launcher, for JUnit 4, see Test runners. These are probably - but I didn't check it - easier to understand than the internals of the runners of Surefire or IntelliJ.