We never test assigning showCurrencyBeforeNumber = false, I guess it is implicitly tested by the other tests because they will fail but the error message will not be related to the showCurrencyBeforeNumber property... There will be no failing test explicitly saying "should put the currency before the number".

Also almost all these tests will fail if we just change the default for showCurrencyBeforeNumber as no test explicitly sets it and they rely on it, same issue for the currency property actually.