My experience is that if you can cheat the tests in this way then they are either too narrow in scope, or badly written tests. This is something that TDD tries

My experience is that if you can cheat the tests in this way then they are either too narrow in scope, or badly written tests. This is something that TDD tries to expose when being adhered to strictly, that is, do the simplest thing to make this test pass - if you `assertTrue(isEmpty())` then I can simply `return true` to make you improve your tests.