The last requirement is the last win condition.
If a player inserts a disc and connects more than three discs of his color in a straight diagonal line, then that player wins.
We need to perform valid game movements to achieve the condition. In this case, we need to test both diagonals across the board: from top-right to bottom-left and from bottom-right to top-left. The following tests use a list of columns to recreate a full game to reproduce the scenario under test:
@Test public void when4Diagonal1DiscsAreConnectedThenThatPlayerWins() { int[] gameplay = new int[] {1, 2, 2, 3, 4, 3, 3, 4, 4, 5, 4}; for (int column : gameplay) { tested.putDiscInColumn(column); } assertThat(tested.getWinner(), is("R")); } @Test public void when4Diagonal2DiscsAreConnectedThenThatPlayerWins() { int[] gameplay = new int[] {3, 4, 2, 3, 2, 2, 1, 1, 1, 1}; for (int column : gameplay) { tested.putDiscInColumn(column); } assertThat(tested.getWinner(), is("G")); }
Again, the checkWinner method needs to be modified, adding new board verifications:
if (winner.isEmpty()) { int startOffset = Math.min(column, row); int myColumn = column - startOffset, myRow = row - startOffset; StringJoiner stringJoiner = new StringJoiner(""); do { stringJoiner .add(board[myRow++][myColumn++]); } while (myColumn < COLUMNS && myRow < ROWS); if (winPattern .matcher(stringJoiner.toString()).matches()) winner = currentPlayer; } if (winner.isEmpty()) { int startOffset = Math.min(column, ROWS - 1 - row); int myColumn = column - startOffset, myRow = row + startOffset; StringJoiner stringJoiner = new StringJoiner(""); do { stringJoiner.add(board[myRow--][myColumn++]); } while (myColumn < COLUMNS && myRow >= 0); if (winPattern.matcher(stringJoiner.toString()).matches()) winner = currentPlayer; }