public void ParseInstruction_AdvancedRotate() { //rotate based on position of letter X //abcde -> abcde deabc, rotates 1 plus value of index (2) //abcde -> eabcd -> deabc -> cdeab _day21.Password = "******"; var instruction = "rotate based on position of letter c"; var result = _day21.AdvancedRotate(instruction); Assert.AreEqual(result, "cdeab"); }