JavaFX tests failing randomly

Question

I have a JUnit Test Class that looks like the following :

public class HelloWorldApplicationTest {

private static TextArea mEditor = new HelloWorldApplication().getmEditor();

@BeforeClass
public static void initToolKit() throws InterruptedException {

    final CountDownLatch latch = new CountDownLatch(1);
    SwingUtilities.invokeLater(() -> {
        new JFXPanel(); // initializes JavaFX environment
        latch.countDown();
    });

    // That's a pretty reasonable delay... Right?
    if (!latch.await(5L, TimeUnit.SECONDS))
        throw new ExceptionInInitializerError();

}


@Test
public void testA(){
    mEditor.setText("111");
    assertTrue(mEditor.getText().equals("111"));
    mEditor.setText("qqq");
    assertTrue(mEditor.getText().equals("qqq"));
    mEditor.setText("eee");
    assertTrue(mEditor.getText().equals("eee"));
    mEditor.setText("aaa");
    assertTrue(mEditor.getText().equals("aaa"));
    mEditor.setText("aaa");
    assertTrue(mEditor.getText().equals("aaa"));
}

@Test
public void testB(){
    mEditor.setText("222");
    assertTrue(mEditor.getText().equals("222"));
    mEditor.setText("222");
    assertTrue(mEditor.getText().equals("222"));
    mEditor.setText("222");
    assertTrue(mEditor.getText().equals("222"));
    mEditor.setText("111");
    assertTrue(mEditor.getText().equals("111"));
}

@Test
public void testC(){
    mEditor.setText("333");
    assertTrue(mEditor.getText().equals("333"));
    mEditor.setText("333");
    assertTrue(mEditor.getText().equals("333"));
    mEditor.setText("TTT");
    assertTrue(mEditor.getText().equals("TTT"));
    mEditor.setText("333");

}

}

If I remove initToolkit method, tests will pass in Linux / OSX , but fail in windows throwing :

java.lang.ExceptionInInitializerError: null
        at com.sun.glass.ui.Screen.getScreens(Screen.java:70)
        at com.sun.glass.ui.Screen.getMainScreen(Screen.java:61)
        at com.sun.javafx.font.PrismFontFactory.getSystemFontSize(PrismFontFactory.java:1911)

Or , mEditor isn't a static variable.

java.lang.RuntimeException: Internal graphics not initialized yet
at com.sun.glass.ui.Screen.getScreens(Screen.java:70)
at com.sun.glass.ui.Screen.getMainScreen(Screen.java:61)
at com.sun.javafx.font.PrismFontFactory.getSystemFontSize(PrismFontFactory.java:1911)

(See : JavaFX Test That fails in Windows and works in OSX and Linux )

If I add initToolkit method, JavaFX environment get initialised, but tests start to fail randomly, and sometimes tests pass ! When I tested on a windows VM with a single processor , tests pass, which could describe here a multithreading issue over static editor ? I've tried synchronized blocks (synchronised(mEditor)) , initializing JavaFX environement by refering to this thread : How do you unit test a JavaFX controller with JUnit, but I always end up with this random behaviour, in which some tests pass, some tests fail and if run again tests could pass or fail randomly.