Matrix-like Computation in Ruby

matrix.rb

# coding: utf-8

class MatrixSum

  def self.sumup_numbers(input)
    # 行の合計を計算
    input_with_row_sum = input.map do |list|
      append_sum_to_last(list)
    end

    # 列の合計を計算
    input_with_row_sum.transpose.map do |list|
      append_sum_to_last(list)
    end.transpose
  end

  def self.format_numbers(result)
    result.map do |line|
      line.map { |num| "%5d"%num }
    end
  end

  def self.generate_input(n)
    Array.new(n) { Array.new(n) { [*1..100].sample } }
  end

  def self.append_sum_to_last(list)
    sum = list.inject(&:+)
    list + [sum]
  end
end

describe MatrixSum do
  describe "#sumup_numbers" do
    input = [
      [52, 96, 15, 20],
      [86, 22, 35, 45],
      [45, 78, 54, 36],
      [16, 86, 74, 55]
    ];

    output = [
      [52, 96, 15, 20, 183],
      [86, 22, 35, 45, 188],
      [45, 78, 54, 36, 213],
      [16, 86, 74, 55, 231],
      [199, 282, 178, 156, 815]
    ];

    let(:n) { input.size }
    let(:result) { MatrixSum.sumup_numbers(input) }
    let(:formatted_result) { MatrixSum.format_numbers(result) }
    let(:table) { numbers.map { |s| s.split(' ') } }
    let(:numbers_by_col) do

    end

    it '何らかのデータが出力されること' do
      p result
      expect(result.size).to be > 1
    end

    it '結果値はoutputに一致すること' do
      p result
      p output
      expect(result).to eq output
    end

    it '各数値は5桁になっていること' do
      formatted_result.each do |line|
        line.each do |n|
          expect(n.size).to eq 5
        end
      end
    end

    it '各数値は右寄せになっていること' do
      formatted_result.each do |line|
        line.each do |n|
          p n
          expect(n).to match(/^\s+\d+$/)
        end
      end
    end

    it 'n+1行になっていること' do
      expect(result.size).to eq n+1
    end

  end

end