Yep

Tests/UnitTests/Extensions.cs

@@ -0,0 +1,97 @@
+using Shogi.Domain.ValueObjects;
+using System;
+using System.Text;
+
+namespace UnitTests;
+
+public static class Extensions
+{
+	/// <summary>
+	/// Prints a ASCII representation of the board for debugging board state.
+	/// </summary>
+	/// <returns></returns>
+	public static string ToStringStateAsAscii(this ShogiBoard board)
+	{
+		var boardState = board.BoardState;
+		var builder = new StringBuilder();
+		builder.Append("                    ");
+		builder.Append("Player 2");
+		builder.AppendLine();
+		for (var rank = 8; rank >= 0; rank--)
+		{
+			// Horizontal line
+			builder.Append("     - ");
+			for (var file = 0; file < 8; file++) builder.Append("- - ");
+			builder.Append("- -");
+
+			// Print Rank ruler.
+			builder.AppendLine();
+			builder.Append($"{rank + 1}  ");
+
+			// Print pieces.
+			builder.Append("  |");
+			for (var x = 0; x < 9; x++)
+			{
+				var piece = boardState[x, rank];
+				if (piece == null)
+				{
+					builder.Append("   ");
+				}
+				else
+				{
+					builder.AppendFormat("{0}", ToAscii(piece));
+				}
+				builder.Append('|');
+			}
+			builder.AppendLine();
+		}
+
+		// Horizontal line
+		builder.Append("     - ");
+		for (var x = 0; x < 8; x++) builder.Append("- - ");
+		builder.Append("- -");
+		builder.AppendLine();
+		builder.Append("                    ");
+		builder.Append("Player 1");
+
+		builder.AppendLine();
+		builder.AppendLine();
+		// Print File ruler.
+		builder.Append("     ");
+		builder.Append("  A   B   C   D   E   F   G   H   I  ");
+
+		return builder.ToString();
+	}
+
+	/// <returns>
+	/// A string with three characters. 
+	/// The first character indicates promotion status. 
+	/// The second character indicates piece. 
+	/// The third character indicates ownership.
+	/// </returns>
+	private static string ToAscii(Piece piece)
+	{
+		var builder = new StringBuilder();
+		if (piece.IsPromoted) builder.Append('^');
+		else builder.Append(' ');
+
+		var name = piece.WhichPiece switch
+		{
+			WhichPiece.King => "K",
+			WhichPiece.GoldGeneral => "G",
+			WhichPiece.SilverGeneral => "S",
+			WhichPiece.Bishop => "B",
+			WhichPiece.Rook => "R",
+			WhichPiece.Knight => "k",
+			WhichPiece.Lance => "L",
+			WhichPiece.Pawn => "P",
+			_ => throw new ArgumentException($"Unknown value for {nameof(WhichPiece)}."),
+		};
+		builder.Append(name);
+
+		if (piece.Owner == WhichPlayer.Player2) builder.Append('.');
+		else builder.Append(' ');
+
+		return builder.ToString();
+	}
+}