Source Launcher

Starting with Java 25 it is possible to write minimal source code test programs using the org.junit.start module. For example, like in a HelloTests.java file reading:

import module org.junit.start;

void main() {
  JUnit.run();
}

@Test
void stringLength() {
  Assertions.assertEquals(11, "Hello JUnit".length());
}

With all required modular JAR files available in a local lib/ directory, the following Java 25+ command will discover and execute tests using the JUnit Platform. It will also print the result tree to the console.

java --module-path lib --add-modules org.junit.start HelloTests.java
╷
└─ JUnit Jupiter ✔
   └─ HelloTests ✔
      └─ stringLength() ✔

Find JUnit’s class API documentation here: JUnit