Bowling Game in Java

BowlingGame.java

package com.feliperibeiro.bowling;

public class BowlingGame {
	int[] rolls;
	int currentRoll;

	public BowlingGame() {
		this.rolls = new int[21];
	}

	public void roll(int p) {
		rolls[currentRoll++] = p;
	}

	public int score() {
		int score = 0;
		int frame = 0;

		for (int i = 0; i < 10; i++) {
			if (isStrike(frame)) {
				score += 10 + strikeBonus(frame);
				frame++;
			} else if (isSpare(frame)) {
				score += 10 + spareBonus(frame);
				frame += 2;
			} else {
				score += sumOfRolls(frame);
				frame += 2;
			}
		}

		return score;
	}

	private boolean isStrike(int frame) {
		return rolls[frame] == 10;
	}

	private boolean isSpare(int frame) {
		return sumOfRolls(frame) == 10;
	}

	private int strikeBonus(int frame) {
		return sumOfRolls(frame+1);
	}

	private int spareBonus(int frame) {
		return rolls[frame+2];
	}

	private int sumOfRolls(int frame) {
		return rolls[frame] + rolls[frame+1];
	}
}

BowlingGameTest.java

package com.feliperibeiro.bowling;

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class BowlingGameTest {

	private BowlingGame g;

	void rollMany(int n, int pins, BowlingGame g) {
		for (int i = 0; i < n; i++) g.roll(pins);
	}

	@Before
	public void setUp() {
		this.g = new BowlingGame();
	}

	@Test
	public void testZero() {
		rollMany(20, 0, g);
		assertEquals(0, g.score());
	}
	
	@Test
	public void testAllOnes() {
		rollMany(20, 1, g);
		assertEquals(20, g.score());
	}

	@Test
	public void testOneSpare() {
		g.roll(5);
		g.roll(5);
		g.roll(3);
		rollMany(17, 0, g);
		assertEquals(16, g.score());
	}
	
	@Test
	public void testOneStrike() {
		g.roll(10);
		g.roll(3);
		g.roll(4);
		rollMany(16, 0, g);
		assertEquals(24, g.score());
	}
	
	@Test
	public void testPerfectGame() {
		rollMany(12, 10, g);
		assertEquals(300, g.score());
	}
}

hello,
i have a question please, when i compil testOneSpare it works what ever i give as values, whereas it does not!! so why??