feat(game): introduce game modes and time control features

modules/io/src/main/resources/META-INF.native-image.de.nowchess.io/reachability-metadata.json

@@ -0,0 +1,27 @@
+{
+  "reflection": [
+    { "type": "scala.Tuple1[]" },
+    { "type": "scala.Tuple2[]" },
+    { "type": "scala.Tuple3[]" },
+    { "type": "scala.Tuple4[]" },
+    { "type": "scala.Tuple5[]" },
+    { "type": "scala.Tuple6[]" },
+    { "type": "scala.Tuple7[]" },
+    { "type": "scala.Tuple8[]" },
+    { "type": "scala.Tuple9[]" },
+    { "type": "scala.Tuple10[]" },
+    { "type": "scala.Tuple11[]" },
+    { "type": "scala.Tuple12[]" },
+    { "type": "scala.Tuple13[]" },
+    { "type": "scala.Tuple14[]" },
+    { "type": "scala.Tuple15[]" },
+    { "type": "scala.Tuple16[]" },
+    { "type": "scala.Tuple17[]" },
+    { "type": "scala.Tuple18[]" },
+    { "type": "scala.Tuple19[]" },
+    { "type": "scala.Tuple20[]" },
+    { "type": "scala.Tuple21[]" },
+    { "type": "scala.Tuple22[]" },
+    { "type": "com.fasterxml.jackson.module.scala.introspect.PropertyDescriptor[]" }
+  ]
+}

modules/io/src/main/scala/de/nowchess/io/GameFileService.scala

@@ -1,5 +1,6 @@
 package de.nowchess.io
 
+import de.nowchess.api.error.GameError
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.io.{GameContextExport, GameContextImport}
 
@@ -12,29 +13,29 @@ import scala.util.Try
   * Abstracts file I/O operations away from the UI layer. Handles both reading and writing game files.
   */
 trait GameFileService:
-  def saveGameToFile(context: GameContext, path: Path, exporter: GameContextExport): Either[String, Unit]
-  def loadGameFromFile(path: Path, importer: GameContextImport): Either[String, GameContext]
+  def saveGameToFile(context: GameContext, path: Path, exporter: GameContextExport): Either[GameError, Unit]
+  def loadGameFromFile(path: Path, importer: GameContextImport): Either[GameError, GameContext]
 
 /** Default implementation using the file system. */
 object FileSystemGameService extends GameFileService:
 
   /** Save a game context to a file using the specified exporter. */
-  def saveGameToFile(context: GameContext, path: Path, exporter: GameContextExport): Either[String, Unit] =
+  def saveGameToFile(context: GameContext, path: Path, exporter: GameContextExport): Either[GameError, Unit] =
     Try {
       val json = exporter.exportGameContext(context)
       Files.write(path, json.getBytes(StandardCharsets.UTF_8))
       ()
     }.fold(
-      ex => Left(s"Failed to save file: ${ex.getMessage}"),
+      ex => Left(GameError.FileWriteError(s"Failed to save file: ${ex.getMessage}")),
       _ => Right(()),
     )
 
   /** Load a game context from a file using the specified importer. */
-  def loadGameFromFile(path: Path, importer: GameContextImport): Either[String, GameContext] =
+  def loadGameFromFile(path: Path, importer: GameContextImport): Either[GameError, GameContext] =
     Try {
       val json = new String(Files.readAllBytes(path), StandardCharsets.UTF_8)
       importer.importGameContext(json)
     }.fold(
-      ex => Left(s"Failed to load file: ${ex.getMessage}"),
+      ex => Left(GameError.FileReadError(s"Failed to load file: ${ex.getMessage}")),
       result => result,
     )

modules/io/src/main/scala/de/nowchess/io/fen/FenParser.scala

@@ -1,6 +1,7 @@
 package de.nowchess.io.fen
 
 import de.nowchess.api.board.*
+import de.nowchess.api.error.GameError
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.io.GameContextImport
 
@@ -8,18 +9,18 @@ object FenParser extends GameContextImport:
 
   /** Parse a complete FEN string into a GameContext. Returns Left with error message if the format is invalid.
     */
-  def parseFen(fen: String): Either[String, GameContext] =
+  def parseFen(fen: String): Either[GameError, GameContext] =
     val parts = fen.trim.split("\\s+")
-    if parts.length != 6 then Left(s"Invalid FEN: expected 6 space-separated fields, got ${parts.length}")
+    if parts.length != 6 then Left(GameError.ParseError(s"Invalid FEN: expected 6 space-separated fields, got ${parts.length}"))
     else
       for
-        board          <- parseBoard(parts(0)).toRight("Invalid FEN: invalid board position")
-        activeColor    <- parseColor(parts(1)).toRight("Invalid FEN: invalid active color (expected 'w' or 'b')")
-        castlingRights <- parseCastling(parts(2)).toRight("Invalid FEN: invalid castling rights")
-        enPassant      <- parseEnPassant(parts(3)).toRight("Invalid FEN: invalid en passant square")
-        halfMoveClock  <- parts(4).toIntOption.toRight("Invalid FEN: invalid half-move clock (expected integer)")
-        fullMoveNumber <- parts(5).toIntOption.toRight("Invalid FEN: invalid full move number (expected integer)")
-        _              <- Either.cond(halfMoveClock >= 0 && fullMoveNumber >= 1, (), "Invalid FEN: invalid move counts")
+        board          <- parseBoard(parts(0)).toRight(GameError.ParseError("Invalid FEN: invalid board position"))
+        activeColor    <- parseColor(parts(1)).toRight(GameError.ParseError("Invalid FEN: invalid active color (expected 'w' or 'b')"))
+        castlingRights <- parseCastling(parts(2)).toRight(GameError.ParseError("Invalid FEN: invalid castling rights"))
+        enPassant      <- parseEnPassant(parts(3)).toRight(GameError.ParseError("Invalid FEN: invalid en passant square"))
+        halfMoveClock  <- parts(4).toIntOption.toRight(GameError.ParseError("Invalid FEN: invalid half-move clock (expected integer)"))
+        fullMoveNumber <- parts(5).toIntOption.toRight(GameError.ParseError("Invalid FEN: invalid full move number (expected integer)"))
+        _              <- Either.cond(halfMoveClock >= 0 && fullMoveNumber >= 1, (), GameError.ParseError("Invalid FEN: invalid move counts"))
       yield GameContext(
         board = board,
         turn = activeColor,
@@ -29,7 +30,7 @@ object FenParser extends GameContextImport:
         moves = List.empty,
       )
 
-  def importGameContext(input: String): Either[String, GameContext] =
+  def importGameContext(input: String): Either[GameError, GameContext] =
     parseFen(input)
 
   /** Parse active color ("w" or "b"). */

modules/io/src/main/scala/de/nowchess/io/fen/FenParserCombinators.scala

@@ -1,6 +1,7 @@
 package de.nowchess.io.fen
 
 import de.nowchess.api.board.*
+import de.nowchess.api.error.GameError
 import de.nowchess.api.game.GameContext
 
 import scala.util.parsing.combinator.RegexParsers
@@ -107,15 +108,15 @@ object FenParserCombinators extends RegexParsers with GameContextImport:
 
   // ── Public API ───────────────────────────────────────────────────────────
 
-  def parseFen(fen: String): Either[String, GameContext] =
+  def parseFen(fen: String): Either[GameError, GameContext] =
     parseAll(fenParser, fen) match
       case Success(ctx, _) => Right(ctx)
-      case other           => Left(s"Invalid FEN: ${other.toString}")
+      case other           => Left(GameError.ParseError(s"Invalid FEN: ${other.toString}"))
 
   def parseBoard(fen: String): Option[Board] =
     parseAll(boardParser, fen) match
       case Success(board, _) => Some(board)
       case _                 => None
 
-  def importGameContext(input: String): Either[String, GameContext] =
+  def importGameContext(input: String): Either[GameError, GameContext] =
     parseFen(input)

modules/io/src/main/scala/de/nowchess/io/fen/FenParserFastParse.scala

@@ -3,6 +3,7 @@ package de.nowchess.io.fen
 import fastparse.*
 import fastparse.NoWhitespace.*
 import de.nowchess.api.board.*
+import de.nowchess.api.error.GameError
 import de.nowchess.api.game.GameContext
 import FenParserSupport.*
 import de.nowchess.api.io.GameContextImport
@@ -103,10 +104,10 @@ object FenParserFastParse extends GameContextImport:
 
   // ── Public API ───────────────────────────────────────────────────────────
 
-  def parseFen(fen: String): Either[String, GameContext] =
+  def parseFen(fen: String): Either[GameError, GameContext] =
     parse(fen, fenParser(using _)) match
       case Parsed.Success(ctx, _) => Right(ctx)
-      case f: Parsed.Failure      => Left(s"Invalid FEN: ${f.msg}")
+      case f: Parsed.Failure      => Left(GameError.ParseError(s"Invalid FEN: ${f.msg}"))
 
   private def boardParserFull(using P[Any]): P[Board] =
     boardParser ~ End
@@ -116,5 +117,5 @@ object FenParserFastParse extends GameContextImport:
       case Parsed.Success(board, _) => Some(board)
       case _                        => None
 
-  def importGameContext(input: String): Either[String, GameContext] =
+  def importGameContext(input: String): Either[GameError, GameContext] =
     parseFen(input)

modules/io/src/main/scala/de/nowchess/io/json/JsonParser.scala

@@ -3,6 +3,7 @@ package de.nowchess.io.json
 import com.fasterxml.jackson.databind.{DeserializationFeature, ObjectMapper}
 import com.fasterxml.jackson.module.scala.DefaultScalaModule
 import de.nowchess.api.board.*
+import de.nowchess.api.error.GameError
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.io.GameContextImport
@@ -27,9 +28,9 @@ object JsonParser extends GameContextImport:
     .registerModule(DefaultScalaModule)
     .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
 
-  def importGameContext(input: String): Either[String, GameContext] =
+  def importGameContext(input: String): Either[GameError, GameContext] =
     Try(mapper.readValue(input, classOf[JsonGameRecord])).toEither.left
-      .map(e => "JSON parsing error: " + e.getMessage)
+      .map(e => GameError.ParseError("JSON parsing error: " + e.getMessage))
       .flatMap { data =>
         val gs       = data.gameState.getOrElse(JsonGameState())
         val rawBoard = gs.board.getOrElse(Nil)
@@ -54,7 +55,7 @@ object JsonParser extends GameContextImport:
         )
       }
 
-  private def parseBoard(pieces: List[JsonPiece]): Either[String, Board] =
+  private def parseBoard(pieces: List[JsonPiece]): Either[GameError, Board] =
     val parsedPieces = pieces.flatMap { p =>
       for
         sq    <- p.square.flatMap(Square.fromAlgebraic)
@@ -64,8 +65,8 @@ object JsonParser extends GameContextImport:
     }
     Right(Board(parsedPieces.toMap))
 
-  private def parseTurn(color: String): Either[String, Color] =
-    parseColor(color).toRight(s"Invalid turn color: $color")
+  private def parseTurn(color: String): Either[GameError, Color] =
+    parseColor(color).toRight(GameError.ParseError(s"Invalid turn color: $color"))
 
   private def parseColor(color: String): Option[Color] =
     if color == "White" then Some(Color.White)
@@ -90,7 +91,7 @@ object JsonParser extends GameContextImport:
       cr.blackQueenSide.getOrElse(false),
     )
 
-  private def parseMoves(moves: List[JsonMove]): Either[String, List[Move]] =
+  private def parseMoves(moves: List[JsonMove]): Either[GameError, List[Move]] =
     Right(moves.flatMap { m =>
       for
         from     <- m.from.flatMap(Square.fromAlgebraic)

modules/io/src/main/scala/de/nowchess/io/json/SquareKeyDeserializer.scala

@@ -1,8 +0,0 @@
-package de.nowchess.io.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/io/src/main/scala/de/nowchess/io/json/SquareKeySerializer.scala

@@ -1,9 +0,0 @@
-package de.nowchess.io.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/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala

@@ -1,6 +1,7 @@
 package de.nowchess.io.pgn
 
 import de.nowchess.api.board.*
+import de.nowchess.api.error.GameError
 import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
 import de.nowchess.api.game.GameContext
 import de.nowchess.api.io.GameContextImport
@@ -17,7 +18,7 @@ object PgnParser extends GameContextImport:
   /** Strictly validate a PGN text. Returns Right(PgnGame) if every move token is a legal move in the evolving position.
     * Returns Left(error message) on the first illegal or impossible move, or any unrecognised token.
     */
-  def validatePgn(pgn: String): Either[String, PgnGame] =
+  def validatePgn(pgn: String): Either[GameError, PgnGame] =
     val lines               = pgn.split("\n").map(_.trim)
     val (headerLines, rest) = lines.span(_.startsWith("["))
     val headers             = parseHeaders(headerLines)
@@ -28,7 +29,7 @@ object PgnParser extends GameContextImport:
     * moves applied and .moves populated. Returns Left(error message) if validation fails or move replay encounters an
     * issue.
     */
-  def importGameContext(input: String): Either[String, GameContext] =
+  def importGameContext(input: String): Either[GameError, GameContext] =
     validatePgn(input).flatMap { game =>
       Right(game.moves.foldLeft(GameContext.initial)((ctx, move) => DefaultRules.applyMove(ctx)(move)))
     }
@@ -173,17 +174,17 @@ object PgnParser extends GameContextImport:
   // ── Strict validation helpers ─────────────────────────────────────────────
 
   /** Walk all move tokens, failing immediately on any unresolvable or illegal move. */
-  private def validateMovesText(moveText: String): Either[String, List[Move]] =
+  private def validateMovesText(moveText: String): Either[GameError, List[Move]] =
     val tokens = moveText.split("\\s+").filter(_.nonEmpty)
     tokens
       .foldLeft(
-        Right((GameContext.initial, Color.White, List.empty[Move])): Either[String, (GameContext, Color, List[Move])],
+        Right((GameContext.initial, Color.White, List.empty[Move])): Either[GameError, (GameContext, Color, List[Move])],
       ) { case (acc, token) =>
         acc.flatMap { case (ctx, color, moves) =>
           if isMoveNumberOrResult(token) then Right((ctx, color, moves))
           else
             parseAlgebraicMove(token, ctx, color) match
-              case None => Left(s"Illegal or impossible move: '$token'")
+              case None => Left(GameError.ParseError(s"Illegal or impossible move: '$token'"))
               case Some(move) =>
                 val nextCtx = DefaultRules.applyMove(ctx)(move)
                 Right((nextCtx, color.opposite, moves :+ move))

modules/io/src/main/scala/de/nowchess/io/service/config/JacksonConfig.scala

@@ -2,10 +2,8 @@ package de.nowchess.io.service.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.io.json.{SquareKeyDeserializer, SquareKeySerializer}
+import de.nowchess.json.ChessJacksonModule
 import io.quarkus.jackson.ObjectMapperCustomizer
 import jakarta.inject.Singleton
 
@@ -18,7 +16,4 @@ class JacksonConfig extends ObjectMapperCustomizer:
         new Version(2, 21, 1, null, "com.fasterxml.jackson.module", "jackson-module-scala")
         // scalafix:on DisableSyntax.null
     })
-    val squareModule = new SimpleModule()
-    squareModule.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
-    squareModule.addKeySerializer(classOf[Square], new SquareKeySerializer())
-    mapper.registerModule(squareModule)
+    mapper.registerModule(new ChessJacksonModule())

modules/io/src/main/scala/de/nowchess/io/service/resource/IoResource.scala

@@ -33,7 +33,7 @@ class IoResource:
     Uni.createFrom().item {
       FenParser.parseFen(body.fen) match
         case Left(err) =>
-          Response.status(400).entity(IoErrorDto("INVALID_FEN", err)).build()
+          Response.status(400).entity(IoErrorDto("INVALID_FEN", err.message)).build()
         case Right(ctx) =>
           Response.ok(ctx).build()
     }
@@ -53,7 +53,7 @@ class IoResource:
     Uni.createFrom().item {
       PgnParser.importGameContext(body.pgn) match
         case Left(err) =>
-          Response.status(400).entity(IoErrorDto("INVALID_PGN", err)).build()
+          Response.status(400).entity(IoErrorDto("INVALID_PGN", err.message)).build()
         case Right(ctx) =>
           Response.ok(ctx).build()
     }

modules/io/src/test/scala/de/nowchess/io/GameFileServiceSuite.scala

@@ -5,6 +5,7 @@ import de.nowchess.api.game.GameContext
 import de.nowchess.api.io.GameContextExport
 import de.nowchess.api.move.Move
 import de.nowchess.io.json.{JsonExporter, JsonParser}
+import org.scalactic.Prettifier.default
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
@@ -128,6 +129,6 @@ class GameFileServiceSuite extends AnyFunSuite with Matchers:
 
       val result = FileSystemGameService.saveGameToFile(context, tmpFile, faultyExporter)
       assert(result.isLeft)
-      assert(result.left.toOption.get.contains("Failed to save file"))
+      assert(result.left.toOption.get.message.contains("Failed to save file"))
     finally Files.deleteIfExists(tmpFile)
   }

modules/io/src/test/scala/de/nowchess/io/fen/FenExporterTest.scala

@@ -97,7 +97,7 @@ class FenExporterTest extends AnyFunSuite with Matchers:
     val fen = FenExporter.gameContextToFen(gameContext)
     FenParser.parseFen(fen) match
       case Right(ctx) => ctx.halfMoveClock shouldBe 42
-      case Left(err)  => fail(s"FEN parsing failed: $err")
+      case Left(err)  => fail(s"FEN parsing failed: ${err.message}")
 
   test("exportGameContext forwards to gameContextToFen"):
     val ctx = GameContext.initial

modules/io/src/test/scala/de/nowchess/io/json/JsonParserTest.scala

@@ -95,13 +95,13 @@ class JsonParserTest extends AnyFunSuite with Matchers:
     val invalidJson = "{ this is not valid json at all }"
     val result      = JsonParser.importGameContext(invalidJson)
     assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
+    assert(result.left.toOption.get.message.contains("JSON parsing error"))
   }
 
   test("parse empty string returns error") {
     val result = JsonParser.importGameContext("")
     assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
+    assert(result.left.toOption.get.message.contains("JSON parsing error"))
   }
 
   test("parse number value returns error") {
@@ -113,7 +113,7 @@ class JsonParserTest extends AnyFunSuite with Matchers:
     val malformed = """{"metadata": {"unclosed": """
     val result    = JsonParser.importGameContext(malformed)
     assert(result.isLeft)
-    assert(result.left.toOption.get.contains("JSON parsing error"))
+    assert(result.left.toOption.get.message.contains("JSON parsing error"))
   }
 
   test("parse invalid JSON array returns error") {
@@ -137,7 +137,7 @@ class JsonParserTest extends AnyFunSuite with Matchers:
     }"""
     val result = JsonParser.importGameContext(json)
     assert(result.isLeft)
-    assert(result.left.toOption.get.contains("Invalid turn color"))
+    assert(result.left.toOption.get.message.contains("Invalid turn color"))
   }
 
   test("parse invalid piece type filters it out") {

modules/io/src/test/scala/de/nowchess/io/json/SquareKeyDeserializerTest.scala

@@ -2,61 +2,50 @@ package de.nowchess.io.json
 
 import com.fasterxml.jackson.core.`type`.TypeReference
 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.io.service.config.JacksonConfig
+import de.nowchess.json.SquareKeyDeserializer
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
 class SquareKeyDeserializerTest extends AnyFunSuite with Matchers:
 
   private def mapper: ObjectMapper =
-    val m   = new ObjectMapper()
-    val mod = new SimpleModule()
-    mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
-    m.registerModule(DefaultScalaModule)
-    m.registerModule(mod)
+    val m = new ObjectMapper()
+    new JacksonConfig().customize(m)
     m
 
   private def readMap(json: String): Map[Square, Int] =
     mapper.readValue(json, new TypeReference[Map[Square, Int]] {})
 
-  test("deserializes valid algebraic key") {
+  test("deserializes valid algebraic key"):
     val result = readMap("""{"e4":1}""")
     result(Square(File.E, Rank.R4)) shouldBe 1
-  }
 
-  test("deserializes a1 corner") {
+  test("deserializes a1 corner"):
     val result = readMap("""{"a1":1}""")
     result(Square(File.A, Rank.R1)) shouldBe 1
-  }
 
-  test("deserializes h8 corner") {
+  test("deserializes h8 corner"):
     val result = readMap("""{"h8":1}""")
     result(Square(File.H, Rank.R8)) shouldBe 1
-  }
 
-  test("deserializes multiple squares") {
+  test("deserializes multiple squares"):
     val result = readMap("""{"a1":1,"h8":2,"e4":3}""")
     result(Square(File.A, Rank.R1)) shouldBe 1
     result(Square(File.H, Rank.R8)) shouldBe 2
     result(Square(File.E, Rank.R4)) shouldBe 3
-  }
 
   // scalafix:off DisableSyntax.null
-  test("deserializeKey returns null for invalid square") {
+  test("deserializeKey returns null for invalid square"):
     new SquareKeyDeserializer().deserializeKey("invalid", null) shouldBe null
-  }
 
-  test("deserializeKey returns null for wrong-length key") {
+  test("deserializeKey returns null for wrong-length key"):
     new SquareKeyDeserializer().deserializeKey("e44", null) shouldBe null
-  }
 
-  test("deserializeKey returns null for bad file") {
+  test("deserializeKey returns null for bad file"):
     new SquareKeyDeserializer().deserializeKey("z4", null) shouldBe null
-  }
 
-  test("deserializeKey returns null for bad rank") {
+  test("deserializeKey returns null for bad rank"):
     new SquareKeyDeserializer().deserializeKey("e9", null) shouldBe null
-  }
   // scalafix:on DisableSyntax.null

modules/io/src/test/scala/de/nowchess/io/json/SquareKeySerializerTest.scala

@@ -2,49 +2,32 @@ package de.nowchess.io.json
 
 import com.fasterxml.jackson.core.`type`.TypeReference
 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.io.service.config.JacksonConfig
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
 class SquareKeySerializerTest extends AnyFunSuite with Matchers:
 
   private def mapper: ObjectMapper =
-    val m   = new ObjectMapper()
-    val mod = new SimpleModule()
-    mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
-    m.registerModule(DefaultScalaModule)
-    m.registerModule(mod)
+    val m = new ObjectMapper()
+    new JacksonConfig().customize(m)
     m
 
-  test("serializes square as algebraic notation") {
+  test("serializes square as algebraic notation"):
     val json = mapper.writeValueAsString(Map(Square(File.E, Rank.R4) -> 1))
     json should include("\"e4\"")
-  }
 
-  test("serializes a1 corner") {
+  test("serializes a1 corner"):
     val json = mapper.writeValueAsString(Map(Square(File.A, Rank.R1) -> 1))
     json should include("\"a1\"")
-  }
 
-  test("serializes h8 corner") {
+  test("serializes h8 corner"):
     val json = mapper.writeValueAsString(Map(Square(File.H, Rank.R8) -> 1))
     json should include("\"h8\"")
-  }
 
-  test("round-trips with SquareKeyDeserializer") {
-    val rt = {
-      val m   = new ObjectMapper()
-      val mod = new SimpleModule()
-      mod.addKeySerializer(classOf[Square], new SquareKeySerializer())
-      mod.addKeyDeserializer(classOf[Square], new SquareKeyDeserializer())
-      m.registerModule(DefaultScalaModule)
-      m.registerModule(mod)
-      m
-    }
+  test("round-trips with SquareKeyDeserializer"):
     val original = Map(Square(File.D, Rank.R5) -> 99)
-    val json     = rt.writeValueAsString(original)
-    val result   = rt.readValue(json, new TypeReference[Map[Square, Int]] {})
+    val json     = mapper.writeValueAsString(original)
+    val result   = mapper.readValue(json, new TypeReference[Map[Square, Int]] {})
     result shouldBe original
-  }