Bowling Game: Array of Ints: Step 15

The enum and the method on whose return type we want to switch look like this:

    enum FrameType { Strike, Spare, Open };
    FrameType FrameTypeAt(int index) const
    {
        if (IsStrike(index)) return FrameType::Strike;
        if (IsSpare (index)) return FrameType::Spare;
                             return FrameType::Open;
    }

And the Score method now looks like this:

    int Score() const
    {
        int score = 0;
        for(int frameIndex=0; frameIndex<20;) // frameIndex will always be at the start of a frame
        {
            switch (FrameTypeAt(frameIndex))
            {
            case FrameType::Strike: score += 10 + SumTwoRolls(++frameIndex);   continue;
            case FrameType::Spare:  score += 10 +         rolls[frameIndex+2]; break;
            case FrameType::Open:   score +=      SumTwoRolls(  frameIndex);   break;
            }
            frameIndex += 2;
        }
        return score;
    }

That’s not terrible, but I’ll let you decide if you think it’s clearer this way or the original multiple ifs way - your choice.

As for me, I want to keep going and to extract a GetOneRoll method, to help line things up, in the FrameType::Spare: case. Like this:

    int Score() const
    {
        int score = 0;
        for(int frameIndex=0; frameIndex<20;) // frameIndex will always be at the start of a frame
        {
            switch (FrameTypeAt(frameIndex))
            {
            case FrameType::Strike: score += 10 + SumTwoRolls(++frameIndex  ); continue;
            case FrameType::Spare:  score += 10 + GetOneRoll (  frameIndex+2); break;
            case FrameType::Open:   score +=      SumTwoRolls(  frameIndex  ); break;
            }
            frameIndex += 2;
        }
        return score;
    }

I can’t think of anything else to refactor so let’s write more tests. How about a test for all strikes, the perfect game test?

Let’s write that, and click Next