Ruby on Rails

 Generally when tests are written, it seems they never cover all possible cases. When you are writing code, you might sometimes think of a case where an unlikely type of input might occur so you convert it from one type to another. Even if your code has just one or two lines that don't get covered, that is enough to knock your coverage grade down considerably. If those particular cases seem unlikely then your most probably going to leave them out because you may not have time to try to cover every last unlikely user error that could happen .. That seems to be the actual reality even if not ideal ,, but I don't see any real remedy to this