refactor(tests): enhance test coverage for move application and piece movement logic

This commit is contained in:
2026-04-05 22:03:40 +02:00
parent 4cf39e3e97
commit 3cec5b8898
14 changed files with 773 additions and 97 deletions
@@ -0,0 +1,300 @@
package de.nowchess.rule
import de.nowchess.api.board.{CastlingRights, Color, Piece, PieceType, Square}
import de.nowchess.api.game.GameContext
import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
import de.nowchess.io.fen.FenParser
import de.nowchess.rules.sets.DefaultRules
import org.scalatest.funsuite.AnyFunSuite
import org.scalatest.matchers.should.Matchers
class DefaultRulesStateTransitionsTest extends AnyFunSuite with Matchers:
private def contextFromFen(fen: String): GameContext =
FenParser.parseFen(fen).fold(err => fail(err), identity)
private def sq(alg: String): Square =
Square.fromAlgebraic(alg).getOrElse(fail(s"Invalid square in test: $alg"))
test("isCheckmate returns true for a known mate pattern"):
val context = contextFromFen("rnb1kbnr/pppp1ppp/8/4p3/6Pq/5P2/PPPPP2P/RNBQKBNR w KQkq - 1 3")
DefaultRules.isCheck(context) shouldBe true
DefaultRules.isCheckmate(context) shouldBe true
DefaultRules.allLegalMoves(context) shouldBe empty
test("isStalemate returns true for a known stalemate pattern"):
val context = contextFromFen("7k/5K2/6Q1/8/8/8/8/8 b - - 0 1")
DefaultRules.isCheck(context) shouldBe false
DefaultRules.isStalemate(context) shouldBe true
DefaultRules.allLegalMoves(context) shouldBe empty
test("isInsufficientMaterial returns true for king versus king"):
val context = contextFromFen("8/8/8/8/8/8/4k3/4K3 w - - 0 1")
DefaultRules.isInsufficientMaterial(context) shouldBe true
test("isInsufficientMaterial returns true for king and bishop versus king"):
val context = contextFromFen("8/8/8/8/8/8/4k3/3BK3 w - - 0 1")
DefaultRules.isInsufficientMaterial(context) shouldBe true
test("isInsufficientMaterial returns false for king and rook versus king"):
val context = contextFromFen("8/8/8/8/8/8/4k3/3RK3 w - - 0 1")
DefaultRules.isInsufficientMaterial(context) shouldBe false
test("isFiftyMoveRule returns true when halfMoveClock is 100"):
val context = contextFromFen("8/8/8/8/8/8/4k3/4K3 w - - 100 1")
DefaultRules.isFiftyMoveRule(context) shouldBe true
test("applyMove toggles turn and records move"):
val move = Move(sq("e2"), sq("e4"))
val next = DefaultRules.applyMove(GameContext.initial, move)
next.turn shouldBe Color.Black
next.moves.lastOption shouldBe Some(move)
test("applyMove sets en passant square after double pawn push"):
val move = Move(sq("e2"), sq("e4"))
val next = DefaultRules.applyMove(GameContext.initial, move)
next.enPassantSquare shouldBe Some(sq("e3"))
test("applyMove clears en passant square for non double pawn push"):
val context = contextFromFen("4k3/8/8/8/8/8/4P3/4K3 w - d6 3 1")
val move = Move(sq("e2"), sq("e3"))
val next = DefaultRules.applyMove(context, move)
next.enPassantSquare shouldBe None
test("applyMove resets halfMoveClock on pawn move"):
val context = contextFromFen("4k3/8/8/8/8/8/4P3/4K3 w - - 12 1")
val move = Move(sq("e2"), sq("e4"))
val next = DefaultRules.applyMove(context, move)
next.halfMoveClock shouldBe 0
test("applyMove increments halfMoveClock on quiet non pawn move"):
val context = contextFromFen("4k3/8/8/8/8/8/8/4K1N1 w - - 7 1")
val move = Move(sq("g1"), sq("f3"))
val next = DefaultRules.applyMove(context, move)
next.halfMoveClock shouldBe 8
test("applyMove resets halfMoveClock on capture"):
val context = contextFromFen("r3k3/8/8/8/8/8/8/R3K3 w Qq - 9 1")
val move = Move(sq("a1"), sq("a8"), MoveType.Normal(isCapture = true))
val next = DefaultRules.applyMove(context, move)
next.halfMoveClock shouldBe 0
next.board.pieceAt(sq("a8")) shouldBe Some(Piece(Color.White, PieceType.Rook))
test("applyMove updates castling rights after king move"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/R3K2R w KQkq - 0 1")
val move = Move(sq("e1"), sq("e2"))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.whiteKingSide shouldBe false
next.castlingRights.whiteQueenSide shouldBe false
next.castlingRights.blackKingSide shouldBe true
next.castlingRights.blackQueenSide shouldBe true
test("applyMove updates castling rights after rook move from h1"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/4K2R w KQkq - 0 1")
val move = Move(sq("h1"), sq("h2"))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.whiteKingSide shouldBe false
next.castlingRights.whiteQueenSide shouldBe true
test("applyMove revokes opponent castling right when rook on starting square is captured"):
val context = contextFromFen("r3k3/8/8/8/8/8/8/R3K3 w Qq - 2 1")
val move = Move(sq("a1"), sq("a8"), MoveType.Normal(isCapture = true))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.blackQueenSide shouldBe false
test("applyMove executes kingside castling and repositions king and rook"):
val context = contextFromFen("4k2r/8/8/8/8/8/8/R3K2R w KQk - 0 1")
val move = Move(sq("e1"), sq("g1"), MoveType.CastleKingside)
val next = DefaultRules.applyMove(context, move)
next.board.pieceAt(sq("g1")) shouldBe Some(Piece(Color.White, PieceType.King))
next.board.pieceAt(sq("f1")) shouldBe Some(Piece(Color.White, PieceType.Rook))
next.board.pieceAt(sq("e1")) shouldBe None
next.board.pieceAt(sq("h1")) shouldBe None
test("applyMove executes queenside castling and repositions king and rook"):
val context = contextFromFen("r3k3/8/8/8/8/8/8/R3K2R w KQq - 0 1")
val move = Move(sq("e1"), sq("c1"), MoveType.CastleQueenside)
val next = DefaultRules.applyMove(context, move)
next.board.pieceAt(sq("c1")) shouldBe Some(Piece(Color.White, PieceType.King))
next.board.pieceAt(sq("d1")) shouldBe Some(Piece(Color.White, PieceType.Rook))
next.board.pieceAt(sq("e1")) shouldBe None
next.board.pieceAt(sq("a1")) shouldBe None
test("applyMove executes en passant and removes captured pawn"):
val context = contextFromFen("k7/8/8/3pP3/8/8/8/7K w - d6 0 1")
val move = Move(sq("e5"), sq("d6"), MoveType.EnPassant)
val next = DefaultRules.applyMove(context, move)
next.board.pieceAt(sq("d6")) shouldBe Some(Piece(Color.White, PieceType.Pawn))
next.board.pieceAt(sq("d5")) shouldBe None
next.board.pieceAt(sq("e5")) shouldBe None
test("applyMove executes promotion with selected piece type"):
val context = contextFromFen("4k3/P7/8/8/8/8/8/4K3 w - - 0 1")
val move = Move(sq("a7"), sq("a8"), MoveType.Promotion(PromotionPiece.Knight))
val next = DefaultRules.applyMove(context, move)
next.board.pieceAt(sq("a8")) shouldBe Some(Piece(Color.White, PieceType.Knight))
next.board.pieceAt(sq("a7")) shouldBe None
test("candidateMoves returns empty for opponent piece on selected square"):
val context = GameContext.initial.withTurn(Color.Black)
DefaultRules.candidateMoves(context, sq("e2")) shouldBe empty
test("legalMoves keeps king safe by filtering pinned bishop moves"):
val context = contextFromFen("8/8/8/8/8/8/r1B1K3/8 w - - 0 1")
val bishopMoves = DefaultRules.legalMoves(context, sq("c2"))
bishopMoves shouldBe empty
test("applyMove preserves black castling rights after white kingside castling"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/R3K2R w KQkq - 0 1")
val move = Move(sq("e1"), sq("g1"), MoveType.CastleKingside)
val next = DefaultRules.applyMove(context, move)
next.castlingRights.whiteKingSide shouldBe false
next.castlingRights.whiteQueenSide shouldBe false
next.castlingRights.blackKingSide shouldBe true
next.castlingRights.blackQueenSide shouldBe true
test("applyMove can revoke both white castling rights when both rooks are captured"):
val context = GameContext(
board = contextFromFen("4k3/8/8/8/8/8/8/R3K2R w KQ - 0 1").board.updated(sq("a8"), Piece(Color.Black, PieceType.Queen)),
turn = Color.Black,
castlingRights = CastlingRights(true, true, false, false),
enPassantSquare = None,
halfMoveClock = 0,
moves = List.empty
)
val afterA1Capture = DefaultRules.applyMove(context, Move(sq("a8"), sq("a1"), MoveType.Normal(isCapture = true)))
val afterH1Capture = DefaultRules.applyMove(afterA1Capture, Move(sq("a1"), sq("h1"), MoveType.Normal(isCapture = true)))
afterH1Capture.castlingRights.whiteKingSide shouldBe false
afterH1Capture.castlingRights.whiteQueenSide shouldBe false
test("isInsufficientMaterial returns true for opposite color bishops only"):
val context = contextFromFen("8/8/8/8/8/8/4k1b1/3BK3 w - - 0 1")
DefaultRules.isInsufficientMaterial(context) shouldBe true
test("candidateMoves for rook includes enemy capture move"):
val context = contextFromFen("4k3/8/8/8/8/8/4K3/R6r w - - 0 1")
val rookMoves = DefaultRules.candidateMoves(context, sq("a1"))
rookMoves.exists(m => m.to == sq("h1") && m.moveType == MoveType.Normal(isCapture = true)) shouldBe true
test("candidateMoves for knight includes enemy capture move"):
val context = contextFromFen("4k3/8/8/8/8/3p4/5N2/4K3 w - - 0 1")
val knightMoves = DefaultRules.candidateMoves(context, sq("f2"))
knightMoves.exists(m => m.to == sq("d3") && m.moveType == MoveType.Normal(isCapture = true)) shouldBe true
test("candidateMoves includes black kingside and queenside castling options"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/4K3 b kq - 0 1")
val kingMoves = DefaultRules.candidateMoves(context, sq("e8"))
kingMoves.exists(_.moveType == MoveType.CastleKingside) shouldBe true
kingMoves.exists(_.moveType == MoveType.CastleQueenside) shouldBe true
test("applyMove executes black kingside castling and repositions pieces on rank 8"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/4K3 b kq - 0 1")
val move = Move(sq("e8"), sq("g8"), MoveType.CastleKingside)
val next = DefaultRules.applyMove(context, move)
next.board.pieceAt(sq("g8")) shouldBe Some(Piece(Color.Black, PieceType.King))
next.board.pieceAt(sq("f8")) shouldBe Some(Piece(Color.Black, PieceType.Rook))
next.board.pieceAt(sq("e8")) shouldBe None
next.board.pieceAt(sq("h8")) shouldBe None
test("applyMove revokes black castling rights when black rook moves from h8"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/4K3 b kq - 0 1")
val move = Move(sq("h8"), sq("h7"))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.blackKingSide shouldBe false
next.castlingRights.blackQueenSide shouldBe true
test("applyMove revokes black queenside castling right when black rook moves from a8"):
val context = contextFromFen("r3k2r/8/8/8/8/8/8/4K3 b kq - 0 1")
val move = Move(sq("a8"), sq("a7"))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.blackKingSide shouldBe true
next.castlingRights.blackQueenSide shouldBe false
test("applyMove revokes black kingside castling right when rook on h8 is captured"):
val context = contextFromFen("4k2r/8/8/8/8/8/8/4K2R w Kk - 0 1")
val move = Move(sq("h1"), sq("h8"), MoveType.Normal(isCapture = true))
val next = DefaultRules.applyMove(context, move)
next.castlingRights.blackKingSide shouldBe false
test("candidateMoves creates all promotion move variants for black pawn"):
val context = contextFromFen("4k3/8/8/8/8/8/p7/4K3 b - - 0 1")
val to = sq("a1")
val pawnMoves = DefaultRules.candidateMoves(context, sq("a2"))
val promotions = pawnMoves.collect { case Move(_, `to`, MoveType.Promotion(piece)) => piece }
promotions.toSet shouldBe Set(
PromotionPiece.Queen,
PromotionPiece.Rook,
PromotionPiece.Bishop,
PromotionPiece.Knight
)
test("applyMove promotion supports queen rook and bishop targets"):
val base = contextFromFen("4k3/P7/8/8/8/8/8/4K3 w - - 0 1")
val queen = DefaultRules.applyMove(base, Move(sq("a7"), sq("a8"), MoveType.Promotion(PromotionPiece.Queen)))
val rook = DefaultRules.applyMove(base, Move(sq("a7"), sq("a8"), MoveType.Promotion(PromotionPiece.Rook)))
val bishop = DefaultRules.applyMove(base, Move(sq("a7"), sq("a8"), MoveType.Promotion(PromotionPiece.Bishop)))
queen.board.pieceAt(sq("a8")) shouldBe Some(Piece(Color.White, PieceType.Queen))
rook.board.pieceAt(sq("a8")) shouldBe Some(Piece(Color.White, PieceType.Rook))
bishop.board.pieceAt(sq("a8")) shouldBe Some(Piece(Color.White, PieceType.Bishop))