fix(rules): Serializers

Added serializers like in IO

modules/rule/src/main/scala/de/nowchess/rules/config/JacksonConfig.scala

@@ -1,11 +1,29 @@
 package de.nowchess.rules.config
 
+import com.fasterxml.jackson.core.Version
 import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.Square
+import de.nowchess.api.move.MoveType
+import de.nowchess.rules.json.*
 import io.quarkus.jackson.ObjectMapperCustomizer
 import jakarta.inject.Singleton
 
 @Singleton
 class JacksonConfig extends ObjectMapperCustomizer:
   def customize(mapper: ObjectMapper): Unit =
-    mapper.registerModule(DefaultScalaModule)
+    mapper.registerModule(new DefaultScalaModule() {
+      override def version(): Version =
+        // scalafix:off DisableSyntax.null
+        new Version(2, 21, 1, null, "com.fasterxml.jackson.module", "jackson-module-scala")
+        // scalafix:on DisableSyntax.null
+    })
+    val mod = new SimpleModule()
+    mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    mod.addSerializer(classOf[Square], new SquareSerializer())
+    mod.addDeserializer(classOf[Square], new SquareDeserializer())
+    mod.addSerializer(classOf[MoveType], new MoveTypeSerializer())
+    mod.addDeserializer(classOf[MoveType], new MoveTypeDeserializer())
+    mapper.registerModule(mod)

modules/rule/src/main/scala/de/nowchess/rules/dto/DtoMapper.scala

@@ -1,128 +0,0 @@
-package de.nowchess.rules.dto
-
-import de.nowchess.api.board.{Board, CastlingRights, Color, Piece, PieceType, Square}
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
-
-object DtoMapper:
-
-  def toColor(s: String): Either[String, Color] = s match
-    case "White" => Right(Color.White)
-    case "Black" => Right(Color.Black)
-    case other   => Left(s"Unknown color: $other")
-
-  def toPieceType(s: String): Either[String, PieceType] = s match
-    case "Pawn"   => Right(PieceType.Pawn)
-    case "Knight" => Right(PieceType.Knight)
-    case "Bishop" => Right(PieceType.Bishop)
-    case "Rook"   => Right(PieceType.Rook)
-    case "Queen"  => Right(PieceType.Queen)
-    case "King"   => Right(PieceType.King)
-    case other    => Left(s"Unknown piece type: $other")
-
-  def toSquare(s: String): Either[String, Square] =
-    Square.fromAlgebraic(s).toRight(s"Invalid square: $s")
-
-  def toMoveType(dto: MoveDto): Either[String, MoveType] = dto.moveType match
-    case "normal"          => Right(MoveType.Normal(isCapture = false))
-    case "capture"         => Right(MoveType.Normal(isCapture = true))
-    case "castleKingside"  => Right(MoveType.CastleKingside)
-    case "castleQueenside" => Right(MoveType.CastleQueenside)
-    case "enPassant"       => Right(MoveType.EnPassant)
-    case "promotion" =>
-      dto.promotionPiece.toRight("Missing promotion piece").flatMap(toPromotionPiece).map(MoveType.Promotion(_))
-    case other => Left(s"Unknown move type: $other")
-
-  def toMove(dto: MoveDto): Either[String, Move] =
-    for
-      from     <- toSquare(dto.from)
-      to       <- toSquare(dto.to)
-      moveType <- toMoveType(dto)
-    yield Move(from, to, moveType)
-
-  def toBoard(pieces: List[PieceOnSquareDto]): Either[String, Board] =
-    sequenceList(pieces.map(toPieceOnSquare)).map(entries => Board(entries.toMap))
-
-  def toGameContext(dto: GameContextDto): Either[String, GameContext] =
-    for
-      board        <- toBoard(dto.board)
-      turn         <- toColor(dto.turn)
-      epSquare     <- sequenceOpt(dto.enPassantSquare.map(toSquare))
-      moves        <- sequenceList(dto.moves.map(toMove))
-      initialBoard <- toBoard(dto.initialBoard)
-    yield GameContext(
-      board = board,
-      turn = turn,
-      castlingRights = toCastlingRights(dto.castlingRights),
-      enPassantSquare = epSquare,
-      halfMoveClock = dto.halfMoveClock,
-      moves = moves,
-      initialBoard = initialBoard,
-    )
-
-  def fromMove(move: Move): MoveDto =
-    val (moveType, promotionPiece) = fromMoveType(move.moveType)
-    MoveDto(move.from.toString, move.to.toString, moveType, promotionPiece)
-
-  def fromBoard(board: Board): List[PieceOnSquareDto] =
-    board.pieces.toList.map { case (sq, p) =>
-      PieceOnSquareDto(sq.toString, p.color.label, p.pieceType.label)
-    }
-
-  def fromGameContext(ctx: GameContext): GameContextDto =
-    GameContextDto(
-      board = fromBoard(ctx.board),
-      turn = ctx.turn.label,
-      castlingRights = fromCastlingRights(ctx.castlingRights),
-      enPassantSquare = ctx.enPassantSquare.map(_.toString),
-      halfMoveClock = ctx.halfMoveClock,
-      moves = ctx.moves.map(fromMove),
-      initialBoard = fromBoard(ctx.initialBoard),
-    )
-
-  private def toPromotionPiece(s: String): Either[String, PromotionPiece] = s match
-    case "Queen"  => Right(PromotionPiece.Queen)
-    case "Rook"   => Right(PromotionPiece.Rook)
-    case "Bishop" => Right(PromotionPiece.Bishop)
-    case "Knight" => Right(PromotionPiece.Knight)
-    case other    => Left(s"Unknown promotion piece: $other")
-
-  private def fromMoveType(mt: MoveType): (String, Option[String]) = mt match
-    case MoveType.Normal(false)   => ("normal", None)
-    case MoveType.Normal(true)    => ("capture", None)
-    case MoveType.CastleKingside  => ("castleKingside", None)
-    case MoveType.CastleQueenside => ("castleQueenside", None)
-    case MoveType.EnPassant       => ("enPassant", None)
-    case MoveType.Promotion(pp)   => ("promotion", Some(fromPromotionPiece(pp)))
-
-  private def fromPromotionPiece(pp: PromotionPiece): String = pp match
-    case PromotionPiece.Queen  => "Queen"
-    case PromotionPiece.Rook   => "Rook"
-    case PromotionPiece.Bishop => "Bishop"
-    case PromotionPiece.Knight => "Knight"
-
-  private def toCastlingRights(dto: CastlingRightsDto): CastlingRights =
-    CastlingRights(dto.whiteKingSide, dto.whiteQueenSide, dto.blackKingSide, dto.blackQueenSide)
-
-  private def fromCastlingRights(cr: CastlingRights): CastlingRightsDto =
-    CastlingRightsDto(cr.whiteKingSide, cr.whiteQueenSide, cr.blackKingSide, cr.blackQueenSide)
-
-  private def toPieceOnSquare(dto: PieceOnSquareDto): Either[String, (Square, Piece)] =
-    for
-      sq        <- toSquare(dto.square)
-      color     <- toColor(dto.color)
-      pieceType <- toPieceType(dto.pieceType)
-    yield sq -> Piece(color, pieceType)
-
-  private def sequenceList[R](list: List[Either[String, R]]): Either[String, List[R]] =
-    list.foldLeft[Either[String, List[R]]](Right(List.empty)) {
-      case (Right(acc), Right(v)) => Right(acc :+ v)
-      case (Left(e), _)           => Left(e)
-      case (_, Left(e))           => Left(e)
-    }
-
-  private def sequenceOpt[R](opt: Option[Either[String, R]]): Either[String, Option[R]] =
-    opt match
-      case None           => Right(None)
-      case Some(Right(v)) => Right(Some(v))
-      case Some(Left(e))  => Left(e)

modules/rule/src/main/scala/de/nowchess/rules/dto/Dtos.scala

@@ -1,37 +1,14 @@
 package de.nowchess.rules.dto
 
-case class PieceOnSquareDto(square: String, color: String, pieceType: String)
+import de.nowchess.api.game.GameContext
+import de.nowchess.api.move.Move
 
-case class CastlingRightsDto(
-    whiteKingSide: Boolean,
-    whiteQueenSide: Boolean,
-    blackKingSide: Boolean,
-    blackQueenSide: Boolean,
-)
+case class ContextRequest(context: GameContext)
 
-case class MoveDto(
-    from: String,
-    to: String,
-    moveType: String,
-    promotionPiece: Option[String],
-)
+case class ContextSquareRequest(context: GameContext, square: String)
 
-case class GameContextDto(
-    board: List[PieceOnSquareDto],
-    turn: String,
-    castlingRights: CastlingRightsDto,
-    enPassantSquare: Option[String],
-    halfMoveClock: Int,
-    moves: List[MoveDto],
-    initialBoard: List[PieceOnSquareDto],
-)
+case class ContextMoveRequest(context: GameContext, move: Move)
 
-case class ContextRequest(context: GameContextDto)
-
-case class ContextSquareRequest(context: GameContextDto, square: String)
-
-case class ContextMoveRequest(context: GameContextDto, move: MoveDto)
-
-case class MovesResponse(moves: List[MoveDto])
+case class MovesResponse(moves: List[Move])
 
 case class BooleanResponse(result: Boolean)

modules/rule/src/main/scala/de/nowchess/rules/json/MoveTypeDeserializer.scala

@@ -0,0 +1,17 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.core.{JsonParseException, JsonParser}
+import com.fasterxml.jackson.databind.node.ObjectNode
+import com.fasterxml.jackson.databind.{DeserializationContext, JsonDeserializer}
+import de.nowchess.api.move.{MoveType, PromotionPiece}
+
+class MoveTypeDeserializer extends JsonDeserializer[MoveType]:
+  override def deserialize(p: JsonParser, ctx: DeserializationContext): MoveType =
+    val node = p.getCodec.readTree[ObjectNode](p)
+    node.get("type").asText() match
+      case "normal"          => MoveType.Normal(node.get("isCapture").asBoolean(false))
+      case "castleKingside"  => MoveType.CastleKingside
+      case "castleQueenside" => MoveType.CastleQueenside
+      case "enPassant"       => MoveType.EnPassant
+      case "promotion"       => MoveType.Promotion(PromotionPiece.valueOf(node.get("piece").asText()))
+      case t                 => throw new JsonParseException(p, s"Unknown move type: $t")

modules/rule/src/main/scala/de/nowchess/rules/json/MoveTypeSerializer.scala

@@ -0,0 +1,23 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.{JsonSerializer, SerializerProvider}
+import de.nowchess.api.move.MoveType
+
+class MoveTypeSerializer extends JsonSerializer[MoveType]:
+  override def serialize(value: MoveType, gen: JsonGenerator, provider: SerializerProvider): Unit =
+    gen.writeStartObject()
+    value match
+      case MoveType.Normal(isCapture) =>
+        gen.writeStringField("type", "normal")
+        gen.writeBooleanField("isCapture", isCapture)
+      case MoveType.CastleKingside =>
+        gen.writeStringField("type", "castleKingside")
+      case MoveType.CastleQueenside =>
+        gen.writeStringField("type", "castleQueenside")
+      case MoveType.EnPassant =>
+        gen.writeStringField("type", "enPassant")
+      case MoveType.Promotion(piece) =>
+        gen.writeStringField("type", "promotion")
+        gen.writeStringField("piece", piece.toString)
+    gen.writeEndObject()

modules/rule/src/main/scala/de/nowchess/rules/json/SquareDeserializer.scala

@@ -0,0 +1,9 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.core.JsonParser
+import com.fasterxml.jackson.databind.{DeserializationContext, JsonDeserializer}
+import de.nowchess.api.board.Square
+
+class SquareDeserializer extends JsonDeserializer[Square]:
+  override def deserialize(p: JsonParser, ctx: DeserializationContext): Square =
+    Square.fromAlgebraic(p.getText).orNull

modules/rule/src/main/scala/de/nowchess/rules/json/SquareKeyDeserializer.scala

@@ -0,0 +1,8 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.databind.{DeserializationContext, KeyDeserializer}
+import de.nowchess.api.board.Square
+
+class SquareKeyDeserializer extends KeyDeserializer:
+  override def deserializeKey(key: String, ctx: DeserializationContext): AnyRef =
+    Square.fromAlgebraic(key).orNull

modules/rule/src/main/scala/de/nowchess/rules/json/SquareKeySerializer.scala

@@ -0,0 +1,9 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.{JsonSerializer, SerializerProvider}
+import de.nowchess.api.board.Square
+
+class SquareKeySerializer extends JsonSerializer[Square]:
+  override def serialize(value: Square, gen: JsonGenerator, provider: SerializerProvider): Unit =
+    gen.writeFieldName(value.toString)

modules/rule/src/main/scala/de/nowchess/rules/json/SquareSerializer.scala

@@ -0,0 +1,9 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.{JsonSerializer, SerializerProvider}
+import de.nowchess.api.board.Square
+
+class SquareSerializer extends JsonSerializer[Square]:
+  override def serialize(value: Square, gen: JsonGenerator, provider: SerializerProvider): Unit =
+    gen.writeString(value.toString)

modules/rule/src/main/scala/de/nowchess/rules/resource/RuleSetResource.scala

@@ -1,5 +1,7 @@
 package de.nowchess.rules.resource
 
+import de.nowchess.api.board.Square
+import de.nowchess.api.game.GameContext
 import de.nowchess.rules.dto.*
 import de.nowchess.rules.sets.DefaultRules
 import jakarta.enterprise.context.ApplicationScoped
@@ -12,9 +14,8 @@ class RuleSetResource:
   private val rules = DefaultRules
 
   // scalafix:off DisableSyntax.throw
-  private def parse[T](e: Either[String, T]): T = e match
-    case Right(v)  => v
-    case Left(msg) => throw BadRequestException(msg)
+  private def parseSquare(s: String): Square =
+    Square.fromAlgebraic(s).getOrElse(throw new BadRequestException(s"Invalid square: $s"))
   // scalafix:on DisableSyntax.throw
 
   @POST
@@ -22,73 +23,67 @@ class RuleSetResource:
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def candidateMoves(req: ContextSquareRequest): MovesResponse =
-    val ctx = parse(DtoMapper.toGameContext(req.context))
-    val sq  = parse(DtoMapper.toSquare(req.square))
-    MovesResponse(rules.candidateMoves(ctx)(sq).map(DtoMapper.fromMove))
+    MovesResponse(rules.candidateMoves(req.context)(parseSquare(req.square)))
 
   @POST
   @Path("/legal-moves")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def legalMoves(req: ContextSquareRequest): MovesResponse =
-    val ctx = parse(DtoMapper.toGameContext(req.context))
-    val sq  = parse(DtoMapper.toSquare(req.square))
-    MovesResponse(rules.legalMoves(ctx)(sq).map(DtoMapper.fromMove))
+    MovesResponse(rules.legalMoves(req.context)(parseSquare(req.square)))
 
   @POST
   @Path("/all-legal-moves")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def allLegalMoves(req: ContextRequest): MovesResponse =
-    MovesResponse(rules.allLegalMoves(parse(DtoMapper.toGameContext(req.context))).map(DtoMapper.fromMove))
+    MovesResponse(rules.allLegalMoves(req.context))
 
   @POST
   @Path("/is-check")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isCheck(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isCheck(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isCheck(req.context))
 
   @POST
   @Path("/is-checkmate")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isCheckmate(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isCheckmate(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isCheckmate(req.context))
 
   @POST
   @Path("/is-stalemate")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isStalemate(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isStalemate(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isStalemate(req.context))
 
   @POST
   @Path("/is-insufficient-material")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isInsufficientMaterial(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isInsufficientMaterial(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isInsufficientMaterial(req.context))
 
   @POST
   @Path("/is-fifty-move-rule")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isFiftyMoveRule(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isFiftyMoveRule(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isFiftyMoveRule(req.context))
 
   @POST
   @Path("/is-threefold-repetition")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
   def isThreefoldRepetition(req: ContextRequest): BooleanResponse =
-    BooleanResponse(rules.isThreefoldRepetition(parse(DtoMapper.toGameContext(req.context))))
+    BooleanResponse(rules.isThreefoldRepetition(req.context))
 
   @POST
   @Path("/apply-move")
   @Consumes(Array(MediaType.APPLICATION_JSON))
   @Produces(Array(MediaType.APPLICATION_JSON))
-  def applyMove(req: ContextMoveRequest): GameContextDto =
-    val ctx  = parse(DtoMapper.toGameContext(req.context))
-    val move = parse(DtoMapper.toMove(req.move))
-    DtoMapper.fromGameContext(rules.applyMove(ctx)(move))
+  def applyMove(req: ContextMoveRequest): GameContext =
+    rules.applyMove(req.context)(req.move)

modules/rule/src/test/scala/de/nowchess/rules/config/JacksonConfigTest.scala

@@ -1,14 +1,30 @@
 package de.nowchess.rules.config
 
 import com.fasterxml.jackson.databind.ObjectMapper
+import de.nowchess.api.board.{File, Rank, Square}
+import de.nowchess.api.move.MoveType
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
 class JacksonConfigTest extends AnyFunSuite with Matchers:
 
-  test("customize registers DefaultScalaModule enabling Option serialization"):
-    val config = new JacksonConfig()
-    val mapper = new ObjectMapper()
-    config.customize(mapper)
+  private val mapper: ObjectMapper =
+    val m = new ObjectMapper()
+    new JacksonConfig().customize(m)
+    m
+
+  test("customize enables Option serialization via DefaultScalaModule"):
     mapper.writeValueAsString(None) shouldBe "null"
     mapper.writeValueAsString(Some("hello")) shouldBe """"hello""""
+
+  test("customize registers SquareSerializer"):
+    mapper.writeValueAsString(Square(File.E, Rank.R4)) shouldBe """"e4""""
+
+  test("customize registers MoveTypeSerializer"):
+    mapper.writeValueAsString(MoveType.CastleKingside) shouldBe """{"type":"castleKingside"}"""
+
+  test("customize registers SquareDeserializer"):
+    mapper.readValue(""""e4"""", classOf[Square]) shouldBe Square(File.E, Rank.R4)
+
+  test("customize registers MoveTypeDeserializer"):
+    mapper.readValue("""{"type":"enPassant"}""", classOf[MoveType]) shouldBe MoveType.EnPassant

modules/rule/src/test/scala/de/nowchess/rules/dto/DtoMapperTest.scala

@@ -1,174 +0,0 @@
-package de.nowchess.rules.dto
-
-import de.nowchess.api.board.{Color, File, Piece, PieceType, Rank, Square}
-import de.nowchess.api.game.GameContext
-import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class DtoMapperTest extends AnyFunSuite with Matchers:
-
-  // ── toColor ────────────────────────────────────────────────────────
-
-  test("toColor converts White"):
-    DtoMapper.toColor("White") shouldBe Right(Color.White)
-
-  test("toColor converts Black"):
-    DtoMapper.toColor("Black") shouldBe Right(Color.Black)
-
-  test("toColor rejects unknown"):
-    DtoMapper.toColor("Red") shouldBe a[Left[?, ?]]
-
-  // ── toPieceType ────────────────────────────────────────────────────
-
-  test("toPieceType converts all piece types"):
-    DtoMapper.toPieceType("Pawn") shouldBe Right(PieceType.Pawn)
-    DtoMapper.toPieceType("Knight") shouldBe Right(PieceType.Knight)
-    DtoMapper.toPieceType("Bishop") shouldBe Right(PieceType.Bishop)
-    DtoMapper.toPieceType("Rook") shouldBe Right(PieceType.Rook)
-    DtoMapper.toPieceType("Queen") shouldBe Right(PieceType.Queen)
-    DtoMapper.toPieceType("King") shouldBe Right(PieceType.King)
-
-  test("toPieceType rejects unknown"):
-    DtoMapper.toPieceType("Dragon") shouldBe a[Left[?, ?]]
-
-  // ── toSquare ───────────────────────────────────────────────────────
-
-  test("toSquare converts valid algebraic"):
-    DtoMapper.toSquare("e4") shouldBe Right(Square(File.E, Rank.R4))
-
-  test("toSquare rejects invalid"):
-    DtoMapper.toSquare("z9") shouldBe a[Left[?, ?]]
-
-  // ── toMoveType ────────────────────────────────────────────────────
-
-  test("toMoveType converts normal non-capture"):
-    DtoMapper.toMoveType(MoveDto("e2", "e4", "normal", None)) shouldBe Right(MoveType.Normal(false))
-
-  test("toMoveType converts capture"):
-    DtoMapper.toMoveType(MoveDto("e2", "d3", "capture", None)) shouldBe Right(MoveType.Normal(true))
-
-  test("toMoveType converts castleKingside"):
-    DtoMapper.toMoveType(MoveDto("e1", "g1", "castleKingside", None)) shouldBe Right(MoveType.CastleKingside)
-
-  test("toMoveType converts castleQueenside"):
-    DtoMapper.toMoveType(MoveDto("e1", "c1", "castleQueenside", None)) shouldBe Right(MoveType.CastleQueenside)
-
-  test("toMoveType converts enPassant"):
-    DtoMapper.toMoveType(MoveDto("e5", "d6", "enPassant", None)) shouldBe Right(MoveType.EnPassant)
-
-  test("toMoveType converts all promotion pieces"):
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", Some("Queen"))) shouldBe Right(
-      MoveType.Promotion(PromotionPiece.Queen),
-    )
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", Some("Rook"))) shouldBe Right(
-      MoveType.Promotion(PromotionPiece.Rook),
-    )
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", Some("Bishop"))) shouldBe Right(
-      MoveType.Promotion(PromotionPiece.Bishop),
-    )
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", Some("Knight"))) shouldBe Right(
-      MoveType.Promotion(PromotionPiece.Knight),
-    )
-
-  test("toMoveType rejects promotion without piece"):
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", None)) shouldBe a[Left[?, ?]]
-
-  test("toMoveType rejects promotion with unknown piece"):
-    DtoMapper.toMoveType(MoveDto("e7", "e8", "promotion", Some("Pawn"))) shouldBe a[Left[?, ?]]
-
-  test("toMoveType rejects unknown type"):
-    DtoMapper.toMoveType(MoveDto("e2", "e4", "unknown", None)) shouldBe a[Left[?, ?]]
-
-  // ── toBoard ───────────────────────────────────────────────────────
-
-  test("toBoard builds valid board"):
-    val pieces = List(
-      PieceOnSquareDto("e1", "White", "King"),
-      PieceOnSquareDto("e8", "Black", "King"),
-    )
-    val result = DtoMapper.toBoard(pieces)
-    result.isRight shouldBe true
-    result.map(_.pieceAt(Square(File.E, Rank.R1))) shouldBe Right(Some(Piece(Color.White, PieceType.King)))
-
-  test("toBoard rejects invalid square"):
-    DtoMapper.toBoard(List(PieceOnSquareDto("z9", "White", "King"))) shouldBe a[Left[?, ?]]
-
-  test("toBoard rejects invalid color"):
-    DtoMapper.toBoard(List(PieceOnSquareDto("e1", "Red", "King"))) shouldBe a[Left[?, ?]]
-
-  test("toBoard rejects invalid piece type"):
-    DtoMapper.toBoard(List(PieceOnSquareDto("e1", "White", "Dragon"))) shouldBe a[Left[?, ?]]
-
-  test("toBoard with multiple invalid pieces covers all sequenceList branches"):
-    val pieces = List(
-      PieceOnSquareDto("z9", "White", "King"),
-      PieceOnSquareDto("z8", "White", "Queen"),
-    )
-    DtoMapper.toBoard(pieces) shouldBe a[Left[?, ?]]
-
-  // ── toGameContext ─────────────────────────────────────────────────
-
-  test("toGameContext round-trips initial position"):
-    val ctx = GameContext.initial
-    val dto = DtoMapper.fromGameContext(ctx)
-    DtoMapper.toGameContext(dto) shouldBe Right(ctx)
-
-  test("toGameContext rejects invalid turn"):
-    val dto = DtoMapper.fromGameContext(GameContext.initial).copy(turn = "Red")
-    DtoMapper.toGameContext(dto) shouldBe a[Left[?, ?]]
-
-  test("toGameContext rejects invalid en passant square"):
-    val dto = DtoMapper.fromGameContext(GameContext.initial).copy(enPassantSquare = Some("z9"))
-    DtoMapper.toGameContext(dto) shouldBe a[Left[?, ?]]
-
-  test("toGameContext rejects invalid initial board"):
-    val badBoard = List(PieceOnSquareDto("z9", "White", "King"))
-    val dto      = DtoMapper.fromGameContext(GameContext.initial).copy(initialBoard = badBoard)
-    DtoMapper.toGameContext(dto) shouldBe a[Left[?, ?]]
-
-  test("toGameContext rejects invalid move"):
-    val badMove = MoveDto("z9", "e4", "normal", None)
-    val dto     = DtoMapper.fromGameContext(GameContext.initial).copy(moves = List(badMove))
-    DtoMapper.toGameContext(dto) shouldBe a[Left[?, ?]]
-
-  // ── fromGameContext ───────────────────────────────────────────────
-
-  test("fromGameContext includes en passant square when present"):
-    val ctx = GameContext.initial.copy(enPassantSquare = Some(Square(File.E, Rank.R3)))
-    DtoMapper.fromGameContext(ctx).enPassantSquare shouldBe Some("e3")
-
-  test("toGameContext round-trips a valid en passant square"):
-    val ctx = GameContext.initial.copy(enPassantSquare = Some(Square(File.E, Rank.R3)))
-    DtoMapper.toGameContext(DtoMapper.fromGameContext(ctx)).map(_.enPassantSquare) shouldBe Right(
-      Some(Square(File.E, Rank.R3)),
-    )
-
-  // ── fromMove ──────────────────────────────────────────────────────
-
-  test("fromMove converts all move types"):
-    DtoMapper.fromMove(Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4))).moveType shouldBe "normal"
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R2), Square(File.D, Rank.R3), MoveType.Normal(true)))
-      .moveType shouldBe "capture"
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R1), Square(File.G, Rank.R1), MoveType.CastleKingside))
-      .moveType shouldBe "castleKingside"
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R1), Square(File.C, Rank.R1), MoveType.CastleQueenside))
-      .moveType shouldBe "castleQueenside"
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R5), Square(File.D, Rank.R6), MoveType.EnPassant))
-      .moveType shouldBe "enPassant"
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R7), Square(File.E, Rank.R8), MoveType.Promotion(PromotionPiece.Queen)))
-      .promotionPiece shouldBe Some("Queen")
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R7), Square(File.E, Rank.R8), MoveType.Promotion(PromotionPiece.Rook)))
-      .promotionPiece shouldBe Some("Rook")
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R7), Square(File.E, Rank.R8), MoveType.Promotion(PromotionPiece.Bishop)))
-      .promotionPiece shouldBe Some("Bishop")
-    DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R7), Square(File.E, Rank.R8), MoveType.Promotion(PromotionPiece.Knight)))
-      .promotionPiece shouldBe Some("Knight")

modules/rule/src/test/scala/de/nowchess/rules/json/JsonSerializersTest.scala

@@ -0,0 +1,98 @@
+package de.nowchess.rules.json
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import de.nowchess.api.board.{File, Rank, Square}
+import de.nowchess.api.move.{MoveType, PromotionPiece}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class JsonSerializersTest extends AnyFunSuite with Matchers:
+
+  private val mapper: ObjectMapper =
+    val m   = new ObjectMapper()
+    val mod = new SimpleModule()
+    m.registerModule(DefaultScalaModule)
+    mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
+    mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
+    mod.addSerializer(classOf[Square], new SquareSerializer())
+    mod.addDeserializer(classOf[Square], new SquareDeserializer())
+    mod.addSerializer(classOf[MoveType], new MoveTypeSerializer())
+    mod.addDeserializer(classOf[MoveType], new MoveTypeDeserializer())
+    m.registerModule(mod)
+    m
+
+  private val e4 = Square(File.E, Rank.R4)
+
+  // ── SquareKeySerializer ───────────────────────────────────────────
+
+  test("SquareKeySerializer writes square as map field name"):
+    mapper.writeValueAsString(Map(e4 -> "piece")) shouldBe """{"e4":"piece"}"""
+
+  // ── SquareKeyDeserializer ─────────────────────────────────────────
+
+  test("SquareKeyDeserializer returns square for valid key"):
+    new SquareKeyDeserializer().deserializeKey("e4", null) shouldBe e4
+
+  test("SquareKeyDeserializer returns null for invalid key"):
+    new SquareKeyDeserializer().deserializeKey("z9", null) shouldBe null
+
+  // ── SquareSerializer/Deserializer ─────────────────────────────────
+
+  test("SquareSerializer writes square as string"):
+    mapper.writeValueAsString(e4) shouldBe """"e4""""
+
+  test("SquareDeserializer reads valid square string"):
+    mapper.readValue(""""e4"""", classOf[Square]) shouldBe e4
+
+  test("SquareDeserializer returns null for invalid square string"):
+    mapper.readValue(""""z9"""", classOf[Square]) shouldBe null
+
+  // ── MoveTypeSerializer ────────────────────────────────────────────
+
+  test("MoveTypeSerializer serializes Normal non-capture"):
+    mapper.writeValueAsString(MoveType.Normal(false)) shouldBe """{"type":"normal","isCapture":false}"""
+
+  test("MoveTypeSerializer serializes Normal capture"):
+    mapper.writeValueAsString(MoveType.Normal(true)) shouldBe """{"type":"normal","isCapture":true}"""
+
+  test("MoveTypeSerializer serializes CastleKingside"):
+    mapper.writeValueAsString(MoveType.CastleKingside) shouldBe """{"type":"castleKingside"}"""
+
+  test("MoveTypeSerializer serializes CastleQueenside"):
+    mapper.writeValueAsString(MoveType.CastleQueenside) shouldBe """{"type":"castleQueenside"}"""
+
+  test("MoveTypeSerializer serializes EnPassant"):
+    mapper.writeValueAsString(MoveType.EnPassant) shouldBe """{"type":"enPassant"}"""
+
+  test("MoveTypeSerializer serializes Promotion"):
+    mapper.writeValueAsString(MoveType.Promotion(PromotionPiece.Queen)) shouldBe
+      """{"type":"promotion","piece":"Queen"}"""
+
+  // ── MoveTypeDeserializer ──────────────────────────────────────────
+
+  test("MoveTypeDeserializer deserializes normal non-capture"):
+    mapper.readValue("""{"type":"normal","isCapture":false}""", classOf[MoveType]) shouldBe
+      MoveType.Normal(false)
+
+  test("MoveTypeDeserializer deserializes normal capture"):
+    mapper.readValue("""{"type":"normal","isCapture":true}""", classOf[MoveType]) shouldBe
+      MoveType.Normal(true)
+
+  test("MoveTypeDeserializer deserializes castleKingside"):
+    mapper.readValue("""{"type":"castleKingside"}""", classOf[MoveType]) shouldBe MoveType.CastleKingside
+
+  test("MoveTypeDeserializer deserializes castleQueenside"):
+    mapper.readValue("""{"type":"castleQueenside"}""", classOf[MoveType]) shouldBe MoveType.CastleQueenside
+
+  test("MoveTypeDeserializer deserializes enPassant"):
+    mapper.readValue("""{"type":"enPassant"}""", classOf[MoveType]) shouldBe MoveType.EnPassant
+
+  test("MoveTypeDeserializer deserializes promotion"):
+    mapper.readValue("""{"type":"promotion","piece":"Rook"}""", classOf[MoveType]) shouldBe
+      MoveType.Promotion(PromotionPiece.Rook)
+
+  test("MoveTypeDeserializer throws for unknown type"):
+    an[Exception] should be thrownBy
+      mapper.readValue("""{"type":"unknown"}""", classOf[MoveType])

modules/rule/src/test/scala/de/nowchess/rules/resource/RuleSetResourceTest.scala

@@ -1,11 +1,11 @@
 package de.nowchess.rules.resource
 
 import com.fasterxml.jackson.databind.ObjectMapper
-import com.fasterxml.jackson.module.scala.DefaultScalaModule
 import de.nowchess.api.board.{Board, CastlingRights, Color, File, Piece, PieceType, Rank, Square}
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.move.Move
-import de.nowchess.rules.dto.{ContextMoveRequest, ContextRequest, ContextSquareRequest, DtoMapper}
+import de.nowchess.rules.config.JacksonConfig
+import de.nowchess.rules.dto.{ContextMoveRequest, ContextRequest, ContextSquareRequest}
 import de.nowchess.rules.sets.DefaultRules
 import io.quarkus.test.junit.QuarkusTest
 import io.restassured.RestAssured
@@ -16,21 +16,25 @@ import org.junit.jupiter.api.Test
 @QuarkusTest
 class RuleSetResourceTest:
 
-  private val mapper = new ObjectMapper().registerModule(DefaultScalaModule)
-  private val rules  = DefaultRules
+  private val mapper: ObjectMapper =
+    val m = new ObjectMapper()
+    new JacksonConfig().customize(m)
+    m
+
+  private val rules = DefaultRules
 
   private def request() = RestAssured.`given`()
 
   private def toJson(value: AnyRef): String = mapper.writeValueAsString(value)
 
   private def contextBody(ctx: GameContext): String =
-    toJson(ContextRequest(DtoMapper.fromGameContext(ctx)))
+    toJson(ContextRequest(ctx))
 
   private def contextSquareBody(ctx: GameContext, square: String): String =
-    toJson(ContextSquareRequest(DtoMapper.fromGameContext(ctx), square))
+    toJson(ContextSquareRequest(ctx, square))
 
   private def contextMoveBody(ctx: GameContext, move: Move): String =
-    toJson(ContextMoveRequest(DtoMapper.fromGameContext(ctx), DtoMapper.fromMove(move)))
+    toJson(ContextMoveRequest(ctx, move))
 
   // ── all-legal-moves ───────────────────────────────────────────────
 
@@ -238,7 +242,7 @@ class RuleSetResourceTest:
   def invalidSquare_returns400(): Unit =
     request()
       .contentType(ContentType.JSON)
-      .body(toJson(ContextSquareRequest(DtoMapper.fromGameContext(GameContext.initial), "z9")))
+      .body(toJson(ContextSquareRequest(GameContext.initial, "z9")))
       .when()
       .post("/api/rules/legal-moves")
       .`then`()

modules/rule/src/test/scala/de/nowchess/rules/resource/RuleSetResourceUnitTest.scala

@@ -2,8 +2,8 @@ package de.nowchess.rules.resource
 
 import de.nowchess.api.board.{Board, CastlingRights, Color, File, Piece, PieceType, Rank, Square}
 import de.nowchess.api.game.GameContext
-import de.nowchess.api.move.{Move, MoveType}
-import de.nowchess.rules.dto.{ContextMoveRequest, ContextRequest, ContextSquareRequest, DtoMapper}
+import de.nowchess.api.move.Move
+import de.nowchess.rules.dto.{ContextMoveRequest, ContextRequest, ContextSquareRequest}
 import de.nowchess.rules.sets.DefaultRules
 import jakarta.ws.rs.BadRequestException
 import org.scalatest.funsuite.AnyFunSuite
@@ -14,9 +14,9 @@ class RuleSetResourceUnitTest extends AnyFunSuite with Matchers:
   private val resource = new RuleSetResource()
   private val rules    = DefaultRules
 
-  private def ctx(g: GameContext)               = ContextRequest(DtoMapper.fromGameContext(g))
-  private def ctxSq(g: GameContext, sq: String) = ContextSquareRequest(DtoMapper.fromGameContext(g), sq)
-  private def ctxMv(g: GameContext, m: Move) = ContextMoveRequest(DtoMapper.fromGameContext(g), DtoMapper.fromMove(m))
+  private def ctx(g: GameContext)               = ContextRequest(g)
+  private def ctxSq(g: GameContext, sq: String) = ContextSquareRequest(g, sq)
+  private def ctxMv(g: GameContext, m: Move)    = ContextMoveRequest(g, m)
 
   // ── position builders ─────────────────────────────────────────────
 
@@ -104,12 +104,6 @@ class RuleSetResourceUnitTest extends AnyFunSuite with Matchers:
   test("isCheck returns true when king is attacked"):
     resource.isCheck(ctx(checkContext())).result shouldBe true
 
-  test("isCheck throws BadRequestException for invalid context"):
-    an[BadRequestException] should be thrownBy
-      resource.isCheck(
-        ctx(GameContext.initial).copy(context = DtoMapper.fromGameContext(GameContext.initial).copy(turn = "Red")),
-      )
-
   // ── isCheckmate ───────────────────────────────────────────────────
 
   test("isCheckmate returns false for initial position"):
@@ -157,11 +151,4 @@ class RuleSetResourceUnitTest extends AnyFunSuite with Matchers:
       .legalMoves(GameContext.initial)(Square(File.E, Rank.R2))
       .find(_.to == Square(File.E, Rank.R4))
       .get
-    resource.applyMove(ctxMv(GameContext.initial, move)).turn shouldBe "Black"
-
-  test("applyMove throws BadRequestException for invalid move"):
-    val badMove = DtoMapper
-      .fromMove(Move(Square(File.E, Rank.R2), Square(File.E, Rank.R4)))
-      .copy(moveType = "unknown")
-    an[BadRequestException] should be thrownBy
-      resource.applyMove(ContextMoveRequest(DtoMapper.fromGameContext(GameContext.initial), badMove))
+    resource.applyMove(ctxMv(GameContext.initial, move)).turn shouldBe Color.Black