Is there a way to avoid writing such an Eclipse plugin by using threads inside
the JUnit test?

I tried this in the test:

        final SWTBot bot = new SWTBot();

        Runnable r = new Runnable() {             public void run() {                 try                 {                     assertNotSame(bot.getDisplay().getThread(),
Thread.currentThread());                     bot.menu("File").click();                     bot.menu("Open Product Teardown...").click();                     bot.button("Open").click();                 }                 catch (Exception e)                 {                     throw new RuntimeException(e);                 }             }         };                 Thread t = new Thread(r);         t.start();

But it didn't work since it throws WidgetNotFoundException. The threads are not
the same, but it does not help in this approach. So I guess another condition
must be met which I don't know of right now.