Avoid negation in an assertTrue or assertFalse test. For example, rephrase: assertTrue(!expr); as: assertFalse(expr);
public class SimpleTest extends TestCase { public void testX() { assertTrue("not empty", !r.isEmpty()); // violation, replace with assertFalse("not empty", r.isEmpty()) assertFalse(!r.isEmpty()); // violation, replace with assertTrue("empty", r.isEmpty()) } }