Record time it takes JUnit tests to run

Question

I would like to record how long it takes my JUnit test to run programmatically. I have a large number of tests in various test classes, and I would like to find out how long ea

Answer 1

Create your own TestWatcher implementation which catches every test method running. Using Guava Stopwatch you can measure time for each test:

public class TimeTestWatcher extends TestWatcher {
    private Stopwatch stopwatch = Stopwatch.createUnstarted();

    protected void starting(Description description) {
        stopwatch.start();
    }

    protected void finished(Description description) {
        stopwatch.stop();

        String testName = description.getMethodName();
        long elapsed = stopwatch.elapsed(TimeUnit.MILLISECONDS);
        System.out.println(String.format("Test %s took %d ms.", testName, elapsed));
    }
};

And then add JUnit @Rule annotation with your TimeTestWatcher for each test class:

public class YourTest {

    @Rule
    public TimeTestWatcher watcher = new TimeTestWatcher();

    @Test
    public void testXXX() {}

    @Test
    public void testYYY() {}
}