Bowling.php

<?php
class Bowling
{
	public $score = 0;

	public function hit($val)
	{
		$this->score += $val;
	}

}

DescribeNewBowlingGame.php

<?php
require 'Bowling.php';

class DescribeNewBowlingGame extends \PHPSpec\Context
{
	private $_bowling = null;

	public function before()
	{
		$this->_bowling = $this->spec(new Bowling);
	}

	public function itShouldScore0ForGutterGame()
	{
		for ($i = 1; $i <= 20; $i++) {
			$this->_bowling->hit(0);
		}
		$this->_bowling->score->should->equal(0);
	}

	public function it1点を20回繰り返すとスコアは20になる()
	{
		for ($i = 1; $i <= 20; $i++) {
			$this->_bowling->hit(0);
		}
		$this->_bowling->score->should->equal(20);
	}

}