Bowling Game: State Machine: Unique_Ptr: Step 22

To pass the “two strikes in a row” test, we need to modify these two methods in the Scorer class:

        void AddStrike()
        {
            if (bonusRolls == 2)
            {
                score += 20;
                bonusRolls = 3;
                ++frame;
                return;
            }

            score += 10;
            bonusRolls = 2;
            ++frame;
        }

        void AddRoll(int pins)
        {
            if ((frame > 10) || ((frame == 10) && (bonusRolls == 0)))
                throw std::out_of_range("can't roll after game has ended");

            if (frame < 10)
                score += pins;

            if (bonusRolls == 1) { score += pins;   bonusRolls = 0; }
            if (bonusRolls == 2) { score += pins;   bonusRolls = 1; }
            if (bonusRolls == 3) { score += pins*2; bonusRolls = 2; }
        }

We added a special case in the AddStrike method for when the previous roll was a strike, in which case we add 20 (equals the strike for this roll and again for the first bonus from the previous strike). Now, I’m really uncomfortable with setting bonusRolls equal to 3, because it’s misleading. It’s not a count anymore (i.e., it’s not that the next three rolls are all bonuses). Instead the next roll counts as a bonus twice, and the one after that as one more bonus.

This tells me I should switch to an enum. So, let’s do that refactoring first, and then click next.