The below code is a test where for no apparent reason the methods with long or Long as return value fail. The resulting stack trace is also somewhat confusing :)

import static org.junit.Assert.assertEquals;

import org.junit.Test;
import org.unitils.UnitilsJUnit4;
import org.unitils.mock.Mock;

public class IntLongTest extends UnitilsJUnit4 {

    interface TestInterface {

        public int getInt(String argument);
        
        public Integer getIntObject(String argument);
        
        public long getLong(String argument);
        
        public Long getLongObject(String argument);
    }

    private Mock<TestInterface> testInterface;

    @Test
    public void testLong() {
        testInterface.onceReturns(1l).getLong("blubber");
        assertEquals(1, testInterface.getMock().getLong("blubber"));
    }
    
    @Test
    public void testLongObject() {
        testInterface.onceReturns(new Long(1l)).getLongObject("blubber2");
        assertEquals(new Long(1l), testInterface.getMock().getLongObject("blubber"));
    }
    
    @Test
    public void testInt() {
        testInterface.onceReturns(1).getInt("blub");
        assertEquals(1, testInterface.getMock().getInt("blub"));
    }
    
    @Test
    public void testIntObject() {
        testInterface.onceReturns(new Integer(1)).getIntObject("blub2");
        assertEquals(new Integer(1), testInterface.getMock().getIntObject("blub2"));
    }
}