The only thing that might 'horrify' me in code review for that is the assumption that it only evaluates true when test failed. (And I might quote '^hello$' per

The only thing that might 'horrify' me in code review for that is the assumption that it only evaluates true when test failed. (And I might quote '^hello$' personally just on principle for having special chars, especially dollar, and to help syntax highlighters.)