score bowling

score_bowling.js

class Game {
  constructor() {
    this.frames = [];
  }
  
  getFrames() {
    return this.frames;
  }
  
  score() {
    let calculatedScore = 0;
    let spare = false;

    for (var i = 0; i < this.frames.length; i++) {
      // Only add second element of array if it exisits - won't exists if first is 10
      // Also, don't add second score of 10th frame if first score is a 10
      calculatedScore += this.frames[i][0] + 
        (this.frames[i][1] ? 
          i == 9 && this.frames[i][0] === 10 ? 
          0 : this.frames[i][1] : 0)
      // calculate spare bonus if previous fream was a spare
      if (spare) {
        calculatedScore += this.frames[i][0]
        spare = false;
      }
      // calculate spare on final frame
      if (i == 9 && this.frames[i][0] !== 10) {
        if (this.frames[i][0] + this.frames[i][1] === 10) {
          calculatedScore += this.frames[i][2]
        }
      }
      if (this.frames[i].length === 2 && this.frames[i][0] + this.frames[i][1] === 10) {
        spare = true;
      }
    }
    
    // Calculate strike bonus
    var framesFlatten = [].concat(...this.frames); // Flatten frames array
    for (var i = 0; i < framesFlatten.length; i++) {
      if (framesFlatten[i] === 10) {
        
        // Don't add strike bonus if on second strike of last frame
        if (!(i === framesFlatten.length - 2 && framesFlatten[i-1] === 10)) {
          calculatedScore += (framesFlatten[i+1] || 0) + (framesFlatten[i+2] || 0)
        }
        
      }
    }
    
    return calculatedScore;
  }

  roll(pin) {
    if (pin < 0 || pin > 10 ) {
      console.log("Not valid pin number.");
      return;
    }
    
    // Tenth frame is different because three rolls are possible
    if (this.frames.length === 10) {
      if (this.frames[this.frames.length-1].length <= 2) {
        // Only allow third score on 10th frame if it starts with a strike or spare
        if (this.frames[this.frames.length-1].length == 2 && 
            this.frames[this.frames.length-1][0] + this.frames[this.frames.length-1][1] <= 10) {
          return;
        }
        this.frames[this.frames.length-1].push(pin);
        return;
      } else {
        console.log("Game over!")
        return;
      }
    }
    
    // Add two rolls per frame if no strike
    if (this.frames.length > 0) {
      if (this.frames[this.frames.length-1].length === 1 && this.frames[this.frames.length-1][0] != 10) {
        this.frames[this.frames.length-1].push(pin)
      } else {
        this.frames.push([pin])  
      }
    } else {
    this.frames.push([pin])  
    }
  } 
}

game = new Game();
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
game.roll(10);
console.log("Test perfect game--");
console.log("expected score: 300, actual score: " + game.score());
console.log(game.getFrames());

game2 = new Game();
game2.roll(10);
game2.roll(7);
game2.roll(3);
game2.roll(9);
game2.roll(0);
game2.roll(10);
game2.roll(0);
game2.roll(8);
game2.roll(8);
game2.roll(2);
game2.roll(0);
game2.roll(6);
game2.roll(10);
game2.roll(10);
game2.roll(10);
game2.roll(8);
game2.roll(1);
console.log("Test average game with spares and strikes--")
console.log("expected score: 167, actual score: " + game2.score());
console.log(game2.getFrames());

game2 = new Game();
game2.roll(3);
game2.roll(7);
game2.roll(3);
game2.roll(3);
game2.roll(3);
game2.roll(3);
console.log("Test partial game with spare--")
console.log("expected score: 25, actual score: " + game2.score());
console.log(game2.getFrames());