For some reason, I was getting an error message that my Ruby code was not throwing an error when I pushed "Test" although my code had this line: raise ArgumentError, "string with illegal characters" if str.empty? || str.match?(/\D/). By commenting out this line, the test passed. However, it wouldn't pass when I pushed "Attempt". So, I removed the # to uncomment the error line before pushing "Attempt", and the code was accepted.