Question

This is my first JUnit test and I don’t understand why is not throwing an AssertionError, what am I doing wrong??

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.JUnitCore;

public class MyFirstJUnitTest {

    public static void main(String[] args) {
        JUnitCore.runClasses(MyFirstJUnitTest.class);
    }

    @Test
    public void simpleAdd() {
        int a = 5;
        int b = 3;

        int c = a + b; //8

        Assert.assertTrue(c == 7);
    }
}

Answer 1

To run JUnit from the command line you need to call the main method.

JUnitCore.main("MyFirstJUnitTest");

You are not supposed to use JUnitCore unless you need to access the result in a programmatic way, for instance if you are writing a JUnit plugin for an IDE:

JUnitCore.runClasses(MyFirstJUnitTest.class).getFailures();

JUnitCore catches any exceptions and stores them in the Result, which is a class that your JUnit plugin will read.