staticMock() and singletons

[ThexXTURBOXx]

Environment

Windows 10 64-bit, Java 14.0.2 x64, mockito-inline 3.6.28, JUnit 5.7.0

Short, Self Contained, Correct (Compilable), Example

http://femtopedia.de/SSCCE.zip

Issue

When we run the given tests, one of them will fail, which shouldn't. I am not entirely sure, what the actual issue is here, but I assume, it has to do with the use of singletons.

When we change the order of the tests or don't use mocking on the objects/classes, the tests pass without issues.

Also, if we "initialize" the singleton before all tests run, the tests also pass.

[ThexXTURBOXx]

Edit: Updated the SSCCE by adding yet another workaround to fix this issue (could help investigating what's wrong here)

[ppanda2021]

I meet the same problem as you when using mockito-inline:4.9.0. My test code as folowing

public class DemoTest {
    @Test
    public void test() {
        try (MockedStatic<DemoSingleTons> mockedStatic = Mockito.mockStatic(DemoSingleTons.class)) {
            DemoSingleTons testUtil1 = Mockito.mock(DemoSingleTons.class);
            mockedStatic.when(DemoSingleTons::getInstance).thenReturn(testUtil1);
            Mockito.when(testUtil1.test(Mockito.anyString())).thenReturn("nothing");
            assertEquals("nothing", DemoSpock.testInput1());
        }
    }

    @Test
    public void test1() {
        try (MockedStatic<DemoSingleTons> mockedStatic = Mockito.mockStatic(DemoSingleTons.class)) {
            DemoSingleTons testUtil1 = Mockito.mock(DemoSingleTons.class);
            mockedStatic.when(DemoSingleTons::getInstance).thenReturn(testUtil1);
            Mockito.when(testUtil1.test(Mockito.anyString())).thenReturn("everything");
            assertEquals("everything", DemoSpock.testInput1());
        }
    }

    @Test
    public void test3() {
        assertEquals("input1", DemoSpock.testInput1());

    }
}

When I executed each use case individually, it's successful. If all tests run together, the latter two use cases will always fail

It looks like the mockStatic behind doesn't take effect.
Looking forward to a reply @mockitoguy @davidkarlsen