Cleaning up after all JUnit tests without explicit

问题:

In Intelij and Eclipse IDEs (and probably some others too) it's possible to run all test classes from a package (or even all test classes in a project) without the need to put each of them explicitly in a test suite class (this is something I want to avoid). Just right click -> run all tests and voilà!

I've got one problem with that approach to testing though. I want to do some cleaning up after all the tests are done, but no matter what I do, nothing seems to work.

At first, I tried using RunListener and its testRunFinished() method, but it is called after every atomic test is done, so not what I want when running many of them.

Then I thought about finalizers and runFinalizersOnExit(true), unfortunatelly, it is deprecated and worked only on one of computers that tests are executed on.

Last thing I tried was to create a "listener" thread, that - given tests execution start and end time differences - would clean up, for instance, after five seconds of test completion. I used code below to test that solution:

import org.junit.Test;

public class Main {
    static {
        System.out.println("In a static block!");

        new Thread(new Runnable() {
            public void run() {
                System.out.println("Starting static thread!");

                try {
                    while (true) {
                        Thread.sleep(1000);
                        System.out.println("Static thread working...");
                    }
                } catch (InterruptedException e) {
                    System.err.println("Static thread interrupted!");
                    e.printStackTrace();
                } catch (Exception e) {
                    System.err.println("Static thread catches exception!");
                    e.printStackTrace();
                } finally {
                    System.err.println("Static thread in finally method.");
                    Thread.currentThread().interrupt();
                }

            }
        }).start();

        System.out.println("Exiting static block!");
    }

    @Test
    public void test() throws Exception {
        System.out.println("Running test!");
        Thread.sleep(3000);
        System.out.println("Stopping test!");
    }
}

With no luck. The thread is killed after the test is done. And even the finally block is never executed...

In a static block!
Exiting static block!
Running test!
Starting static thread!
Static thread working...
Static thread working...
Stopping test!
Static thread working...

Desired behavior would be:

1. right click
2. run all tests
3. TestA is running...
4. TestA done
5. TestB is running...
6. TestB done
7. ... more test classes...
8. cleanup

回答1:

Not sure if I fully have your question right, but I think you want before, beforeClass, after and afterClass methods. i.e.

@BeforeClass
public void beforeClass() {
    // Do stuff before test class is run
}

@Before
public void before() {
    // Do stuff before each test is run
}

@After
public void after() {
    // DO stuff after each test is run
}

@AfterClass
public void afterClass() {
    // DO stuff after test class is run
}

You can do things on a more global level with some hacking or other frameworks. Spring's test suites for example. But I would try to keep such things within the scope of a single test class.

回答2:

I've found a solution to my problem. My colleague suggested "hey, can't you just count the test classes?" - and that's what I did.

A little bit of reflection magic is used here, so the code might not be portable:

public abstract class CleaningTestRunner extends BlockJUnit4ClassRunner {
    protected abstract void cleanupAfterAllTestRuns();

    private static long TEST_CLASSES_AMOUNT;
    private static long TEST_RUNS_FINISHED = 0;
    private static boolean CLASSES_COUNTED = false;

    static {
        while (!CLASSES_COUNTED) {
            try {
                Field f = ClassLoader.class.getDeclaredField("classes");
                f.setAccessible(true);

                Vector<Class> classes = (Vector<Class>) f.get(CleaningTestRunner.class.getClassLoader());
                TEST_CLASSES_AMOUNT = 0;
                for (Class<?> klass : classes) {
                    if (klass.isAnnotationPresent(RunWith.class)) {
                        if (CleaningTestRunner.class.isAssignableFrom(klass.getAnnotation(RunWith.class).value())) {
                            for (Method method : klass.getMethods()) {
                                if (method.isAnnotationPresent(Test.class)) {
                                    ++TEST_CLASSES_AMOUNT;
                                    break;
                                }
                            }
                        }
                    }

                }

                CLASSES_COUNTED = true;
            } catch (Exception ignored) {

            }
        }
    }

    public CleaningTestRunner(Class<?> klass) throws InitializationError {
        super(klass);
    }

    @Override
    public void run(RunNotifier notifier) {
        notifier.addListener(new TestCleanupListener());
        super.run(notifier);
    }

    private class TestCleanupListener extends RunListener {
        @Override
        public void testRunFinished(Result result) throws Exception {
            ++TEST_RUNS_FINISHED;

            if (TEST_RUNS_FINISHED == TEST_CLASSES_AMOUNT) {
                cleanupAfterAllTestRuns();
            }
        }
    }
}