{
  "cases": [
    {
      "description": "an empty board has no winner",
      "board": [
        ". . . . .",
        " . . . . .",
        "  . . . . .",
        "   . . . . .",
        "    . . . . ."
      ],
      "expected": ""
    },
    {
      "description": "X can win on a 1x1 board",
      "board": [
        "X"
      ],
      "expected": "X"
    },
    {
      "description": "O can win on a 1x1 board",
      "board": [
        "O"
      ],
      "expected": "O"
    },
    {
      "description": "only edges does not make a winner",
      "board": [
        "O O O X",
        " X . . X",
        "  X . . X",
        "   X O O O"
      ],
      "expected": ""
    },
    {
      "description": "illegal diagonal does not make a winner",
      "board": [
        "X O . .",
        " O X X X",
        "  O X O .",
        "   . O X .",
        "    X X O O"
      ],
      "expected": ""
    },
    {
      "description": "nobody wins crossing adjacent angles",
      "board": [
         "X . . .",
         " . X O .",
         "  O . X O",
         "   . O . X",
         "    . . O ."
      ],
      "expected": ""
    },
    {
      "description": "X wins crossing from left to right",
      "board": [
        ". O . .",
        " O X X X",
        "  O X O .",
        "   X X O X",
        "    . O X ."
      ],
      "expected": "X"
    },
    {
      "description": "O wins crossing from top to bottom",
      "board": [
        ". O . .",
        " O X X X",
        "  O O O .",
        "   X X O X",
        "    . O X ."
      ],
      "expected": "O"
    },
    {
      "description": "X wins using a convoluted path",
      "board": [
        ". X X . .",
        " X . X . X",
        "  . X . X .",
        "   . X X . .",
        "    O O O O O"
      ], 
      "expected": "X"
    },
    {
      "description": "X wins using a spiral path",
      "board": [
        "O X X X X X X X X",
        " O X O O O O O O O",
        "  O X O X X X X X O",
        "   O X O X O O O X O",
        "    O X O X X X O X O",
        "     O X O O O X O X O",
        "      O X X X X X O X O",
        "       O O O O O O O X O",
        "        X X X X X X X X O"
      ],
      "expected": "X"
    }
  ]
}