How to use

Board

in

com.acme.tictactoe.model

/**
 *  Restart or start a new game, will clear the board and win status
 */
public void restart() {
  clearCells();
  winner = null;
  currentTurn = Player.X;
  state = GameState.IN_PROGRESS;
}

private boolean isValid(int row, int col ) {
  if( state == GameState.FINISHED ) {
    return false;
  } else if( isOutOfBounds(row) || isOutOfBounds(col) ) {
    return false;
  } else if( isCellValueAlreadySet(row, col) ) {
    return false;
  } else {
    return true;
  }
}

public Board() {
  restart();
}

/**
 * Mark the current row for the player who's current turn it is.
 * Will perform no-op if the arguments are out of range or if that position is already played.
 * Will also perform a no-op if the game is already over.
 *
 * @param row 0..2
 * @param col 0..2
 *
 */
public void mark( int row, int col ) {
  if(isValid(row, col)) {
    cells[row][col].setValue(currentTurn);
    if(isWinningMoveByPlayer(currentTurn, row, col)) {
      state = GameState.FINISHED;
      winner = currentTurn;
    } else {
      // flip the current turn and continue
      flipCurrentTurn();
    }
  }
}

/**
 * This test will simulate and verify x is the winner.
 *
 *    X | X | X
 *    O |   |
 *      | O |
 */
@Test
public void test3inRowAcrossTopForX() {
  board.mark(0,0); // x
  assertNull(board.getWinner());
  board.mark(1,0); // o
  assertNull(board.getWinner());
  board.mark(0,1); // x
  assertNull(board.getWinner());
  board.mark(2,1); // o
  assertNull(board.getWinner());
  board.mark(0,2); // x
  assertEquals(Player.X, board.getWinner());
}

@Before
public void setup() {
  board = new Board();
}

/**
 * This test will simulate and verify o is the winner.
 *
 *    O | X | X
 *      | O |
 *      | X | O
 */
@Test
public void test3inRowDiagonalFromTopLeftToBottomForO() {
  board.mark(0,1); // x
  assertNull(board.getWinner());
  board.mark(0,0); // o
  assertNull(board.getWinner());
  board.mark(2,1); // x
  assertNull(board.getWinner());
  board.mark(1,1); // o
  assertNull(board.getWinner());
  board.mark(0,2); // x
  assertNull(board.getWinner());
  board.mark(2,2); // o
  assertEquals(Player.O, board.getWinner());
}