Pair Programming Session 1 - Tic Tac Toe

tictactoe.rb

class TicTacToe

end


class Player
  class << self
		attr_accessor :players

		def clear_players
			@players = []
		end
	end
	def initialize
		@moves = []
		self.class.players ||= []
		self.class.players << self
	end

	attr_accessor :moves
	def play(x,y)
		raise "x is out of bounds" if x < 0 || x > 2
		raise "y is out of bounds" if y < 0 || y > 2

		unless opponents_moves.include?([x, y])
			@moves << [x, y]
		else
			raise "already used"
		end

		@winner = true
	end

	def opponents
		self.class.players
	end

	def opponents_moves
		opponents.map(&:moves).flatten(1)
	end

	def winner?
		@winner
	end
end

tictactoe_spec.rb

require 'rspec/autorun'
require './tictactoe'

describe TicTacToe do
  before(:each) do
	  Player.clear_players
	end
	let(:player) { Player.new }
	it "allows a player to win" do
		player.play(0, 0)
		player.play(0, 1)
		player.play(0, 2)
		player.should be_winner
	end

	it "allows a player to lose" do
		player.should_not be_winner
	end

	it "does not allow plays outside of bounds" do
		expect { player.play(-1, 0) }.to raise_error
		expect { player.play(1, -1) }.to raise_error
		expect { player.play(3, 1) }.to raise_error
		expect { player.play(1, 4) }.to raise_error
	end

	it "does not allow two players to make the same move" do
		player1 = Player.new
		player2 = Player.new

		player1.play(0,0)
		expect { player2.play(0,0) }.to raise_error

	end

end