Test-Driven Java Development - Second Edition

Test – winning condition II

We should also check whether there is a win by filling the vertical line:

@Test
public void whenPlayAndWholeVerticalLineThenWinner() {
  ticTacToe.play(2, 1); // X
  ticTacToe.play(1, 1); // O
  ticTacToe.play(3, 1); // X
  ticTacToe.play(1, 2); // O
  ticTacToe.play(2, 2); // X
  String actual = ticTacToe.play(1, 3); // O
  assertEquals("O is the winner", actual);
}

The player wins when the whole vertical line is occupied by his pieces.