ボウリングプログラムをオブジェクト指向で作成しました。

06.bowling_object/bowling.rb

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+# frozen_string_literal: true
+
+require_relative 'game'
+require_relative 'frame'
+require_relative 'shot'
+
+game = Game.new(ARGV[0])
+puts game.total_score

06.bowling_object/frame.rb

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+# frozen_string_literal: true
+
+require_relative 'shot'
+
+class Frame
+  attr_reader :first_shot, :second_shot, :third_shot
+
+  def initialize(first_score, second_score, third_score = nil)
+    @first_shot = Shot.new(first_score)
+    @second_shot = Shot.new(second_score)
+    @third_shot = third_score.nil? ? nil : Shot.new(third_score)
+  end
+
+  def total_score(next_frame, after_the_next_frame)
+    return [@first_shot, @second_shot, @third_shot].map(&:score).sum unless @third_shot.nil?
+
+    total_score = total_score_first_and_second
+    total_score += strike_bounus(next_frame, after_the_next_frame) if strike?
+    total_score += spare_bounus(next_frame) if spare?
+    total_score
+  end
+
+  def total_score_first_and_second
+    [@first_shot, @second_shot].map(&:score).sum
+  end
+
+  def strike_bounus(next_frame, after_the_next_frame)
+    if next_frame.strike?
+      # 9フレーム目の場合
+      return next_frame.total_score_first_and_second if after_the_next_frame.nil?
+
+      [next_frame.first_shot, after_the_next_frame.first_shot].map(&:score).sum
+    else
+      next_frame.total_score_first_and_second
+    end
+  end
+
+  def spare_bounus(next_frame)
+    next_frame.first_shot.score
+  end
+
+  def spare?
+    @first_shot.score + @second_shot.score == 10 && @first_shot.score != 10
+  end
+
+  def strike?
+    @first_shot.score == 10
+  end
+end

06.bowling_object/game.rb

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+# frozen_string_literal: true
+
+require_relative 'frame'
+
+class Game
+  ONE_TO_NICE_FRAMES_SHOTS_COUNT = 2 * 9
+  def initialize(row_scores)
+    framed_scores = parse_scores(row_scores)
+    # Frameクラス内のfirst_shot, second_shotとは命名の法則が異なっており統一感は無いが、
+    # ここでfirst_frame, second_frame・・・と宣言したら全体の記述が長くなり、
+    # むしろ可読性が落ちると判断したので配列で宣言
+    @frames = framed_scores.map do |score|
+      Frame.new(*score)
+    end
+  end
+
+  def total_score
+    total_score = 0
+    @frames.each_with_index do |frame, index|
+      next_frame, after_the_next_frame = @frames[index + 1, 2]
+      total_score += frame.total_score(next_frame, after_the_next_frame)
+    end
+    total_score
+  end
+
+  private
+
+  def parse_scores(row_scores)
+    scores = []
+    row_scores.split(',').each do |score|
+      scores.length < ONE_TO_NICE_FRAMES_SHOTS_COUNT && score == 'X' ? scores.push('X', '0') : scores << score
+    end
+    tenth_frame_scores = scores[ONE_TO_NICE_FRAMES_SHOTS_COUNT...scores.count]
+    framed_scores = scores.take(ONE_TO_NICE_FRAMES_SHOTS_COUNT).each_slice(2).to_a
+    framed_scores << tenth_frame_scores
+  end
+end

06.bowling_object/shot.rb

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+# frozen_string_literal: true
+
+class Shot
+  attr_reader :score
+
+  def initialize(string_score)
+    @score = string_score == 'X' ? 10 : string_score.to_i
+  end
+end

06.bowling_object/test_bowling.rb

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+# frozen_string_literal: true
+
+require_relative 'game'
+
+def main
+  test_bowling_return_139
+  test_bowling_return_164
+  test_bowling_return_107
+  test_bowling_return_134
+  test_bowling_return_144
+  test_bowling_return_300
+  test_bowling_return_292
+  test_bowling_return_50
+end
+
+def test_bowling_return_139
+  template_test_bowling('6,3,9,0,0,3,8,2,7,3,X,9,1,8,0,X,6,4,5', 139)
+end
+
+def test_bowling_return_164
+  template_test_bowling('6,3,9,0,0,3,8,2,7,3,X,9,1,8,0,X,X,X,X', 164)
+end
+
+def test_bowling_return_107
+  template_test_bowling('0,10,1,5,0,0,0,0,X,X,X,5,1,8,1,0,4', 107)
+end
+
+def test_bowling_return_134
+  template_test_bowling('6,3,9,0,0,3,8,2,7,3,X,9,1,8,0,X,X,0,0', 134)
+end
+
+def test_bowling_return_144
+  template_test_bowling('6,3,9,0,0,3,8,2,7,3,X,9,1,8,0,X,X,1,8', 144)
+end
+
+def test_bowling_return_300
+  template_test_bowling('X,X,X,X,X,X,X,X,X,X,X,X', 300)
+end
+
+def test_bowling_return_292
+  template_test_bowling('X,X,X,X,X,X,X,X,X,X,X,2', 292)
+end
+
+def test_bowling_return_50
+  template_test_bowling('X,0,0,X,0,0,X,0,0,X,0,0,X,0,0', 50)
+end
+
+def template_test_bowling(input, expected)
+  game = Game.new(input)
+  puts "入力したスコア：#{input}"
+  puts "expected: #{expected}"
+
+  total_score = game.total_score
+  puts "actual: #{total_score}"
+
+  if total_score == expected
+    puts '正常'
+  else
+    puts '異常'
+  end
+  puts ''
+end
+
+main