diff --git a/tests/Draw.test.scala b/tests/Draw.test.scala new file mode 100644 index 0000000..3f23eec --- /dev/null +++ b/tests/Draw.test.scala @@ -0,0 +1,46 @@ +package gambit + +class DrawTest extends munit.FunSuite: + + test("insufficient material for bare kings and lone minor") { + assert(Draw.isInsufficientMaterial(Fen.parse("4k3/8/8/8/8/8/8/4K3 w - - 0 1"))) + assert(Draw.isInsufficientMaterial(Fen.parse("4k3/8/8/8/8/8/5B2/4K3 w - - 0 1"))) + assert(Draw.isInsufficientMaterial(Fen.parse("4k3/8/8/8/8/8/5N2/4K3 w - - 0 1"))) + assert(Draw.isInsufficientMaterial(Fen.parse("4k3/8/5b2/8/8/8/8/4K3 b - - 0 1"))) + } + + test("sufficient material is not flagged") { + assert(!Draw.isInsufficientMaterial(Fen.parse("4k3/8/8/8/8/8/5R2/4K3 w - - 0 1"))) + assert(!Draw.isInsufficientMaterial(Fen.parse("4k3/8/8/8/8/8/4PP2/4K3 w - - 0 1"))) + assert(!Draw.isInsufficientMaterial(Fen.parse("4k3/5b2/8/8/8/8/5B2/4K3 w - - 0 1"))) + assert(!Draw.isInsufficientMaterial(Fen.parse(Fen.startPosition))) + } + + test("threefold repetition counts the current position") { + val h = Fen.parse(Fen.startPosition).hash + val other = Fen.parse("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR b KQkq - 0 1").hash + assert(Draw.isThreefold(Vector(h, other, h, other, h), h)) + assert(!Draw.isThreefold(Vector(h, other, h, other), h)) + } + + test("fifty-move rule is a draw in search despite winning material") { + val stalled = Fen.parse("7k/8/8/8/8/8/8/KQ6 w - - 100 1") + assertEquals(new Searcher().search(stalled, 3, 0).score, 0) + val fresh = Fen.parse("7k/8/8/8/8/8/8/KQ6 w - - 0 1") + assert(new Searcher().search(fresh, 3, 0).score > 0, "with a live clock the queen must count") + } + + test("repetition detection sees a matching ancestor at the right distance") { + val pos = Fen.parse("R6k/8/8/8/8/8/8/6K1 w - - 6 30") + val decoy = Fen.parse("R6k/8/8/8/8/8/8/5K2 w - - 6 30").hash + assert(new Searcher().wouldRepeat(pos, Array(pos.hash, decoy))) + assert(!new Searcher().wouldRepeat(pos, Array(decoy, decoy))) + assert(!new Searcher().wouldRepeat(pos, Array(decoy, pos.hash))) + } + + test("self-play from a dead endgame is adjudicated as a draw") { + val insufficient = Game.selfPlay("4k3/8/8/8/8/8/5B2/4K3 w - - 0 1", 20, 4, 0) + assertEquals(insufficient.result, "1/2-1/2 (insufficient material)") + val fifty = Game.selfPlay("4k3/8/8/3p4/3P4/8/8/4K3 w - - 98 1", 200, 3, 0) + assertEquals(fifty.result, "1/2-1/2 (fifty-move rule)") + } diff --git a/tests/TT.test.scala b/tests/TT.test.scala new file mode 100644 index 0000000..dc6d84a --- /dev/null +++ b/tests/TT.test.scala @@ -0,0 +1,76 @@ +package gambit + +class TTTest extends munit.FunSuite: + + test("store then probe returns exact score") { + val tt = new TranspositionTable(16) + tt.store(0x1234L, 5, 123, TT.Exact, 42, 0) + assertEquals(tt.probe(0x1234L, 5, -1000, 1000, 0), 123) + assertEquals(tt.probeMove(0x1234L), 42) + } + + test("lower bound only usable at or above beta") { + val tt = new TranspositionTable(16) + tt.store(0x55L, 5, 200, TT.Lower, 7, 0) + assertEquals(tt.probe(0x55L, 5, -1000, 150, 0), 200) + assertEquals(tt.probe(0x55L, 5, -1000, 300, 0), TT.Unknown) + } + + test("upper bound only usable at or below alpha") { + val tt = new TranspositionTable(16) + tt.store(0x66L, 5, 50, TT.Upper, 8, 0) + assertEquals(tt.probe(0x66L, 5, 100, 1000, 0), 50) + assertEquals(tt.probe(0x66L, 5, 0, 1000, 0), TT.Unknown) + } + + test("shallow entry is not usable for deeper probe") { + val tt = new TranspositionTable(16) + tt.store(0x77L, 3, 10, TT.Exact, 0, 0) + assertEquals(tt.probe(0x77L, 6, -1000, 1000, 0), TT.Unknown) + } + + test("depth preferred replacement keeps the deeper entry") { + val tt = new TranspositionTable(16) + tt.store(0x88L, 8, 300, TT.Exact, 1, 0) + tt.store(0x88L, 4, 999, TT.Exact, 2, 0) + assertEquals(tt.probe(0x88L, 8, -1000, 1000, 0), 300) + } + + test("mate score is stored relative to root distance") { + val tt = new TranspositionTable(16) + val mateAtPly4 = Searcher.MateValue - 4 + tt.store(0x99L, 5, mateAtPly4, TT.Exact, 0, 4) + assertEquals(tt.probe(0x99L, 5, -Searcher.Infinity, Searcher.Infinity, 4), mateAtPly4) + assertEquals(tt.probe(0x99L, 5, -Searcher.Infinity, Searcher.Infinity, 2), Searcher.MateValue - 2) + } + + private val positions = List( + Fen.startPosition, + "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1", + "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 1", + "rnbqkbnr/ppp1pppp/8/3pP3/8/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 3" + ) + + test("transposition table does not change the search score") { + for fen <- positions do + val withTt = new Searcher + withTt.useTt = true + val noTt = new Searcher + noTt.useTt = false + assertEquals( + withTt.search(Fen.parse(fen), 5, 0).score, + noTt.search(Fen.parse(fen), 5, 0).score, + fen + ) + } + + test("transposition table reduces the node count") { + for fen <- positions do + val withTt = new Searcher + withTt.useTt = true + val noTt = new Searcher + noTt.useTt = false + val ttNodes = withTt.search(Fen.parse(fen), 5, 0).nodes + val plainNodes = noTt.search(Fen.parse(fen), 5, 0).nodes + assert(ttNodes < plainNodes, s"$fen: expected TT to prune, got $ttNodes vs $plainNodes") + }