Question

I was wondering if it’s possible to run JUnit tests programatically in parallel when defining parameterized tests. The idea would be to then be able to run them just as regular JUnit tests in Eclipse.

My current code is something similar to:

@RunWith(Parameterized.class)
public class JUnitDivideClassTests {

    @Parameters
    public static Collection<Object[]> data() {

        return Arrays.asList(new Object[][] { { 12, 3, 4 }, { 12, 2, 6}, { 12, 4, 3 }});
    }

    private int n;
    private int d;
    private int q;

    public JUnitDivideClassTests(int n, int d, int q) {

        this.n = n;
        this.d = d;
        this.q = q;
    }

    @Test
    public void test() {

        Assert.assertEquals(q, n / d);
    }
}

as found @ http://codemadesimple.wordpress.com/2012/01/17/paramtest_with_junit/

Answer 1

After some searching, I found that I just had to implement (or rather, use) the following code:

public class ParallelizedParameterized extends Parameterized {
    private static class ThreadPoolScheduler implements RunnerScheduler {
        private ExecutorService executor; 

        public ThreadPoolScheduler() {
            String threads = System.getProperty("junit.parallel.threads", "16");
            int numThreads = Integer.parseInt(threads);
            executor = Executors.newFixedThreadPool(numThreads);
        }

        @Override
        public void finished() {
            executor.shutdown();
            try {
                executor.awaitTermination(10, TimeUnit.MINUTES);
            } catch (InterruptedException exc) {
                throw new RuntimeException(exc);
            }
        }

        @Override
        public void schedule(Runnable childStatement) {
            executor.submit(childStatement);
        }
    }

    public ParallelizedParameterized(Class klass) throws Throwable {
        super(klass);
        setScheduler(new ThreadPoolScheduler());
    }
}

@ http://hwellmann.blogspot.pt/2009/12/running-parameterized-junit-tests-in.html