feat: add GameContext, CastleSide, and Board.withCastle

Introduces GameContext (board + per-side CastlingRights), CastleSide enum, and a Board.withCastle extension method. Also pins missing verification checksums for com.fasterxml:oss-parent:41 and org.junit:junit-bom:5.9.2. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-24 11:20:05 +01:00
parent 38a68549f5
commit 3c8297e1c3
4 changed files with 162 additions and 1 deletions
@@ -0,0 +1,47 @@
+package de.nowchess.chess.logic
+
+import de.nowchess.api.board.{Board, Color, File, Piece, PieceType, Rank, Square}
+import de.nowchess.api.game.CastlingRights
+
+enum CastleSide:
+  case Kingside, Queenside
+
+case class GameContext(
+  board: Board,
+  whiteCastling: CastlingRights,
+  blackCastling: CastlingRights
+):
+  def castlingFor(color: Color): CastlingRights =
+    if color == Color.White then whiteCastling else blackCastling
+
+  def withUpdatedRights(color: Color, rights: CastlingRights): GameContext =
+    if color == Color.White then copy(whiteCastling = rights)
+    else copy(blackCastling = rights)
+
+object GameContext:
+  /** Convenience constructor for test boards: no castling rights on either side. */
+  def apply(board: Board): GameContext =
+    GameContext(board, CastlingRights.None, CastlingRights.None)
+
+  val initial: GameContext =
+    GameContext(Board.initial, CastlingRights.Both, CastlingRights.Both)
+
+extension (b: Board)
+  def withCastle(color: Color, side: CastleSide): Board =
+    val (kingFrom, kingTo, rookFrom, rookTo) = (color, side) match
+      case (Color.White, CastleSide.Kingside)  =>
+        (Square(File.E, Rank.R1), Square(File.G, Rank.R1),
+         Square(File.H, Rank.R1), Square(File.F, Rank.R1))
+      case (Color.White, CastleSide.Queenside) =>
+        (Square(File.E, Rank.R1), Square(File.C, Rank.R1),
+         Square(File.A, Rank.R1), Square(File.D, Rank.R1))
+      case (Color.Black, CastleSide.Kingside)  =>
+        (Square(File.E, Rank.R8), Square(File.G, Rank.R8),
+         Square(File.H, Rank.R8), Square(File.F, Rank.R8))
+      case (Color.Black, CastleSide.Queenside) =>
+        (Square(File.E, Rank.R8), Square(File.C, Rank.R8),
+         Square(File.A, Rank.R8), Square(File.D, Rank.R8))
+    val king = Piece(color, PieceType.King)
+    val rook = Piece(color, PieceType.Rook)
+    Board(b.pieces.removed(kingFrom).removed(rookFrom)
+                  .updated(kingTo, king).updated(rookTo, rook))
@@ -0,0 +1,81 @@
+package de.nowchess.chess.logic
+
+import de.nowchess.api.board.*
+import de.nowchess.api.game.CastlingRights
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class GameContextTest extends AnyFunSuite with Matchers:
+
+  private def sq(f: File, r: Rank): Square = Square(f, r)
+  private def board(entries: (Square, Piece)*): Board = Board(entries.toMap)
+
+  test("GameContext.initial has Board.initial and CastlingRights.Both for both sides"):
+    GameContext.initial.board         shouldBe Board.initial
+    GameContext.initial.whiteCastling shouldBe CastlingRights.Both
+    GameContext.initial.blackCastling shouldBe CastlingRights.Both
+
+  test("castlingFor returns white rights for Color.White"):
+    GameContext.initial.castlingFor(Color.White) shouldBe CastlingRights.Both
+
+  test("castlingFor returns black rights for Color.Black"):
+    GameContext.initial.castlingFor(Color.Black) shouldBe CastlingRights.Both
+
+  test("withUpdatedRights updates white castling without touching black"):
+    val ctx = GameContext.initial.withUpdatedRights(Color.White, CastlingRights.None)
+    ctx.whiteCastling shouldBe CastlingRights.None
+    ctx.blackCastling shouldBe CastlingRights.Both
+
+  test("withUpdatedRights updates black castling without touching white"):
+    val ctx = GameContext.initial.withUpdatedRights(Color.Black, CastlingRights.None)
+    ctx.blackCastling shouldBe CastlingRights.None
+    ctx.whiteCastling shouldBe CastlingRights.Both
+
+  test("withCastle: white kingside — king e1→g1, rook h1→f1"):
+    val b = board(
+      sq(File.E, Rank.R1) -> Piece.WhiteKing,
+      sq(File.H, Rank.R1) -> Piece.WhiteRook
+    )
+    val after = b.withCastle(Color.White, CastleSide.Kingside)
+    after.pieceAt(sq(File.G, Rank.R1)) shouldBe Some(Piece.WhiteKing)
+    after.pieceAt(sq(File.F, Rank.R1)) shouldBe Some(Piece.WhiteRook)
+    after.pieceAt(sq(File.E, Rank.R1)) shouldBe None
+    after.pieceAt(sq(File.H, Rank.R1)) shouldBe None
+
+  test("withCastle: white queenside — king e1→c1, rook a1→d1"):
+    val b = board(
+      sq(File.E, Rank.R1) -> Piece.WhiteKing,
+      sq(File.A, Rank.R1) -> Piece.WhiteRook
+    )
+    val after = b.withCastle(Color.White, CastleSide.Queenside)
+    after.pieceAt(sq(File.C, Rank.R1)) shouldBe Some(Piece.WhiteKing)
+    after.pieceAt(sq(File.D, Rank.R1)) shouldBe Some(Piece.WhiteRook)
+    after.pieceAt(sq(File.E, Rank.R1)) shouldBe None
+    after.pieceAt(sq(File.A, Rank.R1)) shouldBe None
+
+  test("withCastle: black kingside — king e8→g8, rook h8→f8"):
+    val b = board(
+      sq(File.E, Rank.R8) -> Piece.BlackKing,
+      sq(File.H, Rank.R8) -> Piece.BlackRook
+    )
+    val after = b.withCastle(Color.Black, CastleSide.Kingside)
+    after.pieceAt(sq(File.G, Rank.R8)) shouldBe Some(Piece.BlackKing)
+    after.pieceAt(sq(File.F, Rank.R8)) shouldBe Some(Piece.BlackRook)
+    after.pieceAt(sq(File.E, Rank.R8)) shouldBe None
+    after.pieceAt(sq(File.H, Rank.R8)) shouldBe None
+
+  test("withCastle: black queenside — king e8→c8, rook a8→d8"):
+    val b = board(
+      sq(File.E, Rank.R8) -> Piece.BlackKing,
+      sq(File.A, Rank.R8) -> Piece.BlackRook
+    )
+    val after = b.withCastle(Color.Black, CastleSide.Queenside)
+    after.pieceAt(sq(File.C, Rank.R8)) shouldBe Some(Piece.BlackKing)
+    after.pieceAt(sq(File.D, Rank.R8)) shouldBe Some(Piece.BlackRook)
+    after.pieceAt(sq(File.E, Rank.R8)) shouldBe None
+    after.pieceAt(sq(File.A, Rank.R8)) shouldBe None
+
+  test("GameContext single-arg apply defaults to CastlingRights.None for both sides"):
+    val ctx = GameContext(Board.initial)
+    ctx.whiteCastling shouldBe CastlingRights.None
+    ctx.blackCastling shouldBe CastlingRights.None