Contents

require 'spec_helper'

describe RoundRobinTournament do
  it 'has a version number' do
    expect(RoundRobinTournament::VERSION).not_to be nil
  end

  describe '#schedule' do
    (2..20).to_a.each do |n|
      it "is correct for #{n} numbers" do
        schedule = RoundRobinTournament.schedule((1..n).to_a)
        expect { check_schedule!(schedule) }.not_to raise_error
      end
    end

    it 'works with array of any stuff' do
      Student = Struct.new(:name)
      students = %w(John Paul Ringo George).map { |beatle| Student.new beatle }

      teams = RoundRobinTournament.schedule(students)
      expect { check_schedule!(teams) }.not_to raise_error
    end

    it 'is stable growing the number of participants by 1' do
      day_four = RoundRobinTournament.schedule(%w[a b c d]).first
      day_five = RoundRobinTournament.schedule(%w[a b c d e]).first
      expect(day_five[0..1]).to eq(day_four)
      expect(day_five.last).to eq(['e', nil])
    end

    it 'is stable growing the number of participants by 2' do
      day_four = RoundRobinTournament.schedule(%w[a b c d]).first
      day_six = RoundRobinTournament.schedule(%w[a b c d e f]).first
      expect(day_six[0..1]).to eq(day_four)
      expect(day_six.last).to eq(['e', 'f'])
    end
  end

  def check_schedule!(schedule)
    schedule.each_with_index do |games, day|
      games.each_with_index do |game, game_id|
        schedule.each_with_index do |other_games, other_day|
          next if day == other_day
          other_games.each_with_index do |other_game, other_game_id|
            fail if game_id != other_game_id && same_game?(game, other_game)
          end
        end
      end
    end
  end

  def same_game?(game, other_game)
    (game.first == other_game.first && game.last == other_game.last) ||
      (game.last == other_game.first && game.first == other_game.last)
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
round_robin_tournament-0.1.0	spec/round_robin_tournament_spec.rb