minesweeper-codex/tests/Minesweeper.Tests/TestBoards.cs

using Minesweeper.Game;

namespace Minesweeper.Tests;

/// <summary>Builds fixed boards from a layout where 'x' marks a mine.</summary>
internal static class TestBoards
{
    public const char Mine = 'x';

    public static Board Create(params string[] layout)
    {
        if (layout.Length == 0)
            throw new ArgumentException("A layout needs at least one row.", nameof(layout));

        var height = layout.Length;
        var width = layout[0].Length;
        var mines = new List<CellRef>();

        for (var y = 0; y < height; y++)
        {
            if (layout[y].Length != width)
                throw new ArgumentException($"Layout row {y} is {layout[y].Length} wide, expected {width}.", nameof(layout));
            for (var x = 0; x < width; x++)
                if (layout[y][x] == Mine)
                    mines.Add(new CellRef(x, y));
        }

        var board = new Board(width, height, 0);
        board.PlantMines(mines);
        return board;
    }

    public static MinesweeperGame Game(int seed, params string[] layout) =>
        new(Create(layout), new Random(seed));

    public static MinesweeperGame SingleMine(int width = 4, int height = 4, int seed = 1) =>
        Game(seed, Rows(width, height, new CellRef(0, 0)));

    public static string[] Rows(int width, int height, params CellRef[] mines)
    {
        var rows = new string[height];
        for (var y = 0; y < height; y++)
        {
            var characters = new char[width];
            for (var x = 0; x < width; x++)
                characters[x] = mines.Contains(new CellRef(x, y)) ? Mine : '.';
            rows[y] = new string(characters);
        }

        return rows;
    }
}