modules/core/src/main/scala/de/nowchess/chess/logic/GameHistory.scala

@@ -2,20 +2,20 @@ package de.nowchess.chess.logic
 
 import de.nowchess.api.board.Square
 
-/** A single move in the game history. */
-case class Move(
+/** A single move recorded in the game history. Distinct from api.move.Move which represents user intent. */
+case class HistoryMove(
   from: Square,
   to: Square,
   castleSide: Option[CastleSide] = None
 )
 
 /** Complete game history: ordered list of moves. */
-case class GameHistory(moves: List[Move] = List.empty):
-  def addMove(move: Move): GameHistory =
+case class GameHistory(moves: List[HistoryMove] = List.empty):
+  def addMove(move: HistoryMove): GameHistory =
     GameHistory(moves :+ move)
 
   def addMove(from: Square, to: Square, castleSide: Option[CastleSide] = None): GameHistory =
-    addMove(Move(from, to, castleSide))
+    addMove(HistoryMove(from, to, castleSide))
 
 object GameHistory:
   val empty: GameHistory = GameHistory()

modules/core/src/test/scala/de/nowchess/chess/controller/GameControllerTest.scala

@@ -2,7 +2,7 @@ package de.nowchess.chess.controller
 
 import de.nowchess.api.board.*
 import de.nowchess.api.game.CastlingRights
-import de.nowchess.chess.logic.{CastleSide, GameHistory, Move}
+import de.nowchess.chess.logic.{CastleSide, GameHistory}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 

modules/core/src/test/scala/de/nowchess/chess/logic/GameHistoryTest.scala

@@ -34,3 +34,8 @@ class GameHistoryTest extends AnyFunSuite with Matchers:
       Some(CastleSide.Kingside)
     )
     history.moves.head.castleSide shouldBe Some(CastleSide.Kingside)
+
+  test("GameHistory.addMove with two arguments uses None for castleSide default"):
+    val history = GameHistory.empty.addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4))
+    history.moves should have length 1
+    history.moves.head.castleSide shouldBe None

modules/core/src/test/scala/de/nowchess/chess/logic/GameRulesTest.scala

@@ -2,7 +2,7 @@ package de.nowchess.chess.logic
 
 import de.nowchess.api.board.*
 import de.nowchess.api.game.CastlingRights
-import de.nowchess.chess.logic.{GameHistory, Move}
+import de.nowchess.chess.logic.GameHistory
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
@@ -122,3 +122,16 @@ class GameRulesTest extends AnyFunSuite with Matchers:
       )
     // No history means castling rights are intact
     GameRules.gameStatus(b, GameHistory.empty, Color.White) shouldBe PositionStatus.Normal
+
+  test("CastleSide.withCastle correctly positions pieces for Queenside castling"):
+    // Directly test the withCastle extension for Queenside (coverage gap on line 10)
+    val b = board(
+      sq(File.E, Rank.R1) -> Piece.WhiteKing,
+      sq(File.A, Rank.R1) -> Piece.WhiteRook,
+      sq(File.H, Rank.R8) -> Piece.BlackKing
+    )
+    val result = b.withCastle(Color.White, CastleSide.Queenside)
+    result.pieceAt(sq(File.C, Rank.R1)) shouldBe Some(Piece.WhiteKing)
+    result.pieceAt(sq(File.D, Rank.R1)) shouldBe Some(Piece.WhiteRook)
+    result.pieceAt(sq(File.E, Rank.R1)) shouldBe None
+    result.pieceAt(sq(File.A, Rank.R1)) shouldBe None