JUnit's assertEquals method has the form assertEquals(X expected, X actual), but most of the tests here have expected and actual in the wrong parameter slot. The result should be the same (since equality is symmetric), but the test output will be incorrect. For example, assertEquals produces the output "java.lang.AssertionError: expected: , but was: " where E is the value you expect and A is the actual value read from the code under test. Current tests will have those values reversed which can cause confusion while debugging.