Changes to isDraw and isGameOver (to fix #112) and fixes for games that include put/remove

.eslintrc.cjs

@@ -27,6 +27,7 @@ module.exports = {
         format: ['PascalCase'],
       },
     ],
-    'multiline-comment-style': ['error', 'starred-block']
+    'multiline-comment-style': ['error', 'starred-block'], 
+    "@typescript-eslint/no-non-null-assertion": 'allow'
   },
 }

README.md

@@ -424,17 +424,36 @@ chess.isCheckmate()
 // -> true
 ```
 
-### .isDraw()
+### .canClaimDraw() 
 
-Returns true or false if the game is drawn (50-move rule or insufficient
-material).
+Returns true or false if a draw can be claimed in the current position as per Article 9 of the [FIDE Laws of Chess](https://handbook.fide.com/chapter/E012023), ie. if `.isThreefoldRepetition()` or `.isFiftyMoveRule()`.
+
+
+### .isDraw({ strict = false }: { strict?: boolean } = {})
+
+Returns true or false if the game is drawn (by stalemate, insufficient material, threefold repetition or 50-move rule).
+
+If optional `{ strict: true }` argument is given, returns true or false if the game is strictly drawn as per Article 9 of the [FIDE Laws of Chess](https://handbook.fide.com/chapter/E012023) (by stalemate, insufficient material, fivefold repetition or 75-move rule).
 
 ```ts
 const chess = new Chess('4k3/4P3/4K3/8/8/8/8/8 b - - 0 78')
 chess.isDraw()
 // -> true
 ```
 
+```ts
+const chess = new Chess('8/8/8/2R5/8/7K/8/k2r4 w - - 149 129')
+chess.isDraw()
+// -> true
+
+chess.isDraw({ strict: true })
+// -> false
+
+chess.move('Rd5')
+chess.isDraw({ strict: true })
+// -> true
+```
+
 ### .isInsufficientMaterial()
 
 Returns true if the game is drawn due to insufficient material (K vs. K, K vs.
@@ -446,10 +465,11 @@ chess.isInsufficientMaterial()
 // -> true
 ```
 
-### .isGameOver()
+### .isGameOver({ strict = false }: { strict?: boolean } = {})
+
+Returns true if the game has ended via checkmate or draw (by stalemate, insufficient material, threefold repetition or 50-move rule). Otherwise, returns false.
 
-Returns true if the game has ended via checkmate, stalemate, draw, threefold
-repetition, or insufficient material. Otherwise, returns false.
+If optional `{ strict: true }` argument is given, it determines whether the game is strictly drawn as per Article 9 of the [FIDE Laws of Chess](https://handbook.fide.com/chapter/E012023) (by stalemate, insufficient material, fivefold repetition or 75-move rule).
 
 ```ts
 const chess = new Chess()
@@ -499,6 +519,73 @@ chess.move('Nf3') chess.move('Nf6') chess.move('Ng1') chess.move('Ng8')
 chess.isThreefoldRepetition()
 // -> true
 ```
+### .isFivefoldRepetition()
+
+Returns true or false if the current board position has occurred five or more
+times.
+
+```ts
+const chess = new Chess('rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1')
+// -> true
+// rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq occurs 1st time
+chess.isFivefoldRepetition()
+// -> false
+
+chess.move('Nf3') chess.move('Nf6') chess.move('Ng1') chess.move('Ng8')
+// rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq occurs 2nd time
+chess.isFivefoldRepetition()
+// -> false
+
+chess.move('Nf3') chess.move('Nf6') chess.move('Ng1') chess.move('Ng8')
+chess.move('Nf3') chess.move('Nf6') chess.move('Ng1') chess.move('Ng8') 
+chess.move('Nf3') chess.move('Nf6') chess.move('Ng1') chess.move('Ng8')
+// rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq occurs 5th time
+chess.isFivefoldRepetition()
+// -> true
+```
+
+### .isFiftyMoveRule()
+
+Returns true or false if the [fifty-move rule](https://en.wikipedia.org/wiki/Fifty-move_rule) is in effect.
+
+```ts
+const chess = new Chess('8/2R5/5K2/1k6/8/8/8/4r3 w - - 99 104')
+
+chess.isFiftyMoveRule()
+// -> false
+
+chess.move('Kf5')
+chess.isFiftyMoveRule()
+// -> true
+
+chess.move('Re5')
+chess.isFiftyMoveRule()
+// -> true
+
+chess.move('Kxe5')
+chess.isFiftyMoveRule()
+// -> false
+```
+
+### .isSeventyFiveMoveRule()
+
+Returns true or false if the [seventy-five-move rule](https://en.wikipedia.org/wiki/Fifty-move_rule#Seventy-five-move_rule) is in effect.
+
+
+```ts
+const chess = new Chess('8/8/8/2R5/8/7K/8/k2r4 w - - 149 129')
+
+chess.isSeventyFiveMoveRule()
+// -> false
+
+chess.move('Rd5')
+chess.isSeventyFiveMoveRule()
+// -> true
+
+chess.move('Rxd5')
+chess.isSeventyFiveMoveRule()
+// -> false
+```
 
 ### .load(fen)
 

__tests__/comments.test.ts

@@ -244,6 +244,21 @@ describe('Load Comments', () => {
 
 {test comment} 16. ... Rfb8`,
     },
+    {
+      name: 'bracket comments without spaces',
+      input: '1. e4{e4 is good}e5',
+      output: '1. e4 {e4 is good} e5',
+    },
+    {
+      name: 'semicolon comments without spaces',
+      input: '1. e4;e4 is good\ne5',
+      output: '1. e4 {e4 is good} e5',
+    },
+    {
+      name: 'multiple comments for the same move',
+      input: '1. e4 {e4 is good} {it is well studied} e5',
+      output: '1. e4 {e4 is good it is well studied} e5',
+    },
   ]
 
   tests.forEach((test) => {
@@ -254,3 +269,54 @@ describe('Load Comments', () => {
     })
   })
 })
+
+describe('Put/remove comments', () => {
+  it('adds puts as comments', () => {
+    const chess = new Chess()
+    chess.move('e4')
+    chess.put({type: 'p', color: 'w'}, 'e2')
+    expect(chess.pgn()).toBe('1. e4 {Chess.js: w p put on e2}')
+  })
+  it('adds removes as comments', () => {
+    const chess = new Chess()
+    chess.move('e4')
+    chess.remove('d2')
+    expect(chess.pgn()).toBe('1. e4 {Chess.js: w p removed from d2}')
+  })
+  it('adds multiple puts/removes in the same turn', () => {
+    const chess = new Chess()
+    chess.move('e4')
+    chess.put({type: 'p', color: 'w'}, 'e2')
+    chess.remove('d2')
+    expect(chess.pgn()).toBe('1. e4 {Chess.js: w p put on e2} {Chess.js: w p removed from d2}')
+  })
+  it('loads puts from comments', () => {
+    const chess = new Chess()
+    chess.loadPgn('1. e4 {Chess.js: w p put on e2}')
+    expect(chess.fen()).toBe('rnbqkbnr/pppppppp/8/8/4P3/8/PPPPPPPP/RNBQKBNR b KQkq - 0 1')
+  })
+  it('loads removes from comments', () => {
+    const chess = new Chess()
+    chess.loadPgn('1. e4 {Chess.js: w p removed from d2}')
+    expect(chess.fen()).toBe('rnbqkbnr/pppppppp/8/8/4P3/8/PPP2PPP/RNBQKBNR b KQkq - 0 1')
+  })
+  it('loads multiple puts/removes in the same turn', () => {
+    const chess = new Chess()
+    chess.loadPgn('1. e4 {Chess.js: w p put on e2} {Chess.js: w p removed from d2}')
+    expect(chess.fen()).toBe('rnbqkbnr/pppppppp/8/8/4P3/8/PPP1PPPP/RNBQKBNR b KQkq - 0 1')
+  })
+  it('can .loadPgn with puts generated by .pgn', () => {
+    const chess = new Chess()
+    chess.loadPgn('1. e4 f6 2. Qh5+')
+    chess.put({type: 'p', color:'b'}, 'f7')
+    chess.move('Nc6')  // illegal move without the put
+    expect(() => chess.loadPgn(chess.pgn())).not.toThrow()
+  })
+  it('can .loadPgn with removes generated by .pgn', () => {
+    const chess = new Chess()
+    chess.loadPgn('1. g3 e6 2. Bg2 Ne7 3. Bc6')
+    chess.remove('b8')
+    chess.move('Nxc6')  // ambiguous SAN without the remove
+    expect(() => chess.loadPgn(chess.pgn())).not.toThrow()
+  })
+})

__tests__/is-draw.test.ts

@@ -0,0 +1,58 @@
+import { Chess } from '../src/chess'
+
+test('isDraw - strict mode, fivefold repetition', () => {
+  const moves = 'Nf3 Nf6 Ng1 Ng8 Nf3 Nf6 Ng1 Ng8 Nf3 Nf6 Ng1 Ng8'.split(/\s+/)
+  const chess = new Chess()
+
+  moves.forEach((move) => {
+    expect(chess.isDraw({strict: true})).toBe(false)
+    chess.move(move)
+  })
+
+  expect(chess.isDraw()).toBe(true)
+  expect(chess.isDraw({strict: true})).toBe(false)
+  chess.move('Nf3')
+  chess.move('Nf6')
+  chess.move('Ng1')
+  chess.move('Ng8')
+  expect(chess.isDraw({strict: true})).toBe(true)
+
+})
+
+test('isDraw - strict mode, seventy-five-move rule', () => {
+  const pgn = `1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 
+  9.c3 Be7 10.Re1 O-O 11.Nbd2 Nc5 12.Bc2 d4 13.Nf1 d3 14.Bb3 Nxb3 15.axb3 Qd7 16.Ng5 Bf5 
+  17.Ng3 Bg6 18.h4 Rfd8 19.Bd2 h6 20.h5 Bf5 21.Nxf5 Qxf5 22.Qf3 Qxf3 23.Nxf3 a5 24.Re4 Rd5 
+  25.Rae1 Rad8 26.g4 Ra8 27.Kg2 Kf8 28.Nd4 Nxd4 29.Rxd4 Rxd4 30.cxd4 Rd8 31.Be3 Rd5 32.Rd1 
+  c5 33.dxc5 Bxc5 34.Bxc5+ Rxc5 35.Rxd3 Rxe5 36.Rd8+ Ke7 37.Ra8 b4 38.Kf3 Rc5 39.Ra7+ Ke6 
+  40.Ke4 Rc2 41.Ra6+ Ke7 42.Rxa5 Rxb2 43.f4 Rxb3 44.Rb5 Rb1 45.g5 b3 46.gxh6 gxh6 47.Kf5 b2
+  48.Rb7+ Ke8 49.Kf6 Rh1 50.Rxb2 Rxh5 51.Rb8+ Kd7 52.Kxf7 Rf5+ 53.Kg6 Rxf4 54.Kxh6 Ke6 
+  55.Rb6+ Kf7 56.Rb7+ Kf6 57.Rb6+ Kf5 58.Rb5+ Kg4 59.Rg5+ Kf3 60.Rb5 Ra4 61.Kg5 Ra1 62.Rb3+
+  Ke4 63.Rb4+ Kd5 64.Rb5+ Kc6 65.Rb2 Kc5 66.Kf4 Kd4 67.Rd2+ Kc3 68.Rd7 Kc2 69.Ke3 Ra3+ 
+  70.Ke4 Ra4+ 71.Ke5 Ra8 72.Ke4 Kc3 73.Kf5 Ra5+ 74.Kg4 Kc4 75.Kh4 Ra4 76.Kh3 Kc5 77.Kh2 
+  Kc6 78.Rd2 Kc5 79.Kh3 Ra3+ 80.Kh4 Kc6 81.Kh5 Kc7 82.Kh6 Kc8 83.Kh7 Rh3+ 84.Kg6 Kc7 85.Kf7
+  Kc6 86.Ke6 Kc5 87.Kf5 Kc4 88.Kg4 Rh8 89.Rd7 Rg8+ 90.Kf3 Kc5 91.Kf4 Rf8+ 92.Ke5 Kc6 93.Rd2 
+  Re8+ 94.Kf4 Rf8+ 95.Ke5 Kc5 96.Ke4 Kc4 97.Rc2+ Kb3 98.Rc7 Re8+ 99.Kd5 Rd8+ 100.Ke6 Kb4 
+  101.Kf6 Rd1 102.Ke6 Kb5 103.Kf6 Re1 104.Kf5`
+  const moves = pgn.split(/\s*\d+\.\s*|\s+/).slice(1)
+  const strictPgn = `104.Rd1 105.Rc8 Ka5 106.Kf4 Re1 107.Kg4 Ka4 108.Rb8 
+  Rf1 109.Kg5 Ka3 110.Rc8 Ka2 111.Kh5 Re1 112.Kg5 Ka1 113.Rc7 Rf1 114.Rd7 Kb2 115.Kg6 Re1 116.
+  Rc7 Kb1 117.Kg5 Re2 118.Rc4 Re6 119.Kg4 Kb2 120.Kg3 Ka3 121.Rc2 Re8 122.Kg2 Ka4 123.Rc4+ Ka3 
+  124.Kg1 Re2 125.Rc5 Ka2 126.Kh1 Re1+ 127.Kh2 Ka1 128.Kh3 Rd1 129.Rd5`
+  const strictMoves = strictPgn.split(/\s*\d+\.\s*|\s+/).slice(1)
+
+  const chess = new Chess()
+  moves.forEach((move) => {
+    expect(chess.isDraw()).toBe(false)
+    expect(chess.isDraw({strict: true})).toBe(false)
+    chess.move(move)
+  })
+
+  strictMoves.forEach((move) => {
+    expect(chess.isDraw()).toBe(true)
+    expect(chess.isDraw({strict: true})).toBe(false)
+    chess.move(move)
+  })
+  expect(chess.isDraw()).toBe(true)
+  expect(chess.isDraw({strict: true})).toBe(true)
+})

__tests__/is-fifty-move-rule.test.ts

@@ -0,0 +1,33 @@
+import { Chess } from '../src/chess'
+
+test('isFiftyMoveRule', () => {
+  const pgn = `1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Nxe4 6. d4 b5 7. Bb3 d5 8. dxe5
+  Be6 9. c3 Be7 10. Re1 O-O 11. Nbd2 Nc5 12. Bc2 d4 13. Nf1 d3 14. Bb3 Nxb3 15.
+  axb3 Qd7 16. Ng5 Bf5 17. Ng3 Bg6 18. h4 Rfd8 19. Bd2 h6 20. h5 Bf5 21. Nxf5 Qxf5
+  22. Qf3 Qxf3 23. Nxf3 a5 24. Re4 Rd5 25. Rae1 Rad8 26. g4 Ra8 27. Kg2 Kf8 28.
+  Nd4 Nxd4 29. Rxd4 Rxd4 30. cxd4 Rd8 31. Be3 Rd5 32. Rd1 c5 33. dxc5 Bxc5 34.
+  Bxc5+ Rxc5 35. Rxd3 Rxe5 36. Rd8+ Ke7 37. Ra8 b4 38. Kf3 Rc5 39. Ra7+ Ke6 40.
+  Ke4 Rc2 41. Ra6+ Ke7 42. Rxa5 Rxb2 43. f4 Rxb3 44. Rb5 Rb1 45. g5 b3 46. gxh6
+  gxh6 47. Kf5 b2 48. Rb7+ Ke8 49. Kf6 Rh1 50. Rxb2 Rxh5 51. Rb8+ Kd7 52. Kxf7
+  Rf5+ 53. Kg6 Rxf4 54. Kxh6 Ke6 55. Rb6+ Kf7 56. Rb7+ Kf6 57. Rb6+ Kf5 58. Rb5+
+  Kg4 59. Rg5+ Kf3 60. Rb5 Ra4 61. Kg5 Ra1 62. Rb3+ Ke4 63. Rb4+ Kd5 64. Rb5+ Kc6
+  65. Rb2 Kc5 66. Kf4 Kd4 67. Rd2+ Kc3 68. Rd7 Kc2 69. Ke3 Ra3+ 70. Ke4 Ra4+ 71.
+  Ke5 Ra8 72. Ke4 Kc3 73. Kf5 Ra5+ 74. Kg4 Kc4 75. Kh4 Ra4 76. Kh3 Kc5 77. Kh2 Kc6
+  78. Rd2 Kc5 79. Kh3 Ra3+ 80. Kh4 Kc6 81. Kh5 Kc7 82. Kh6 Kc8 83. Kh7 Rh3+ 84.
+  Kg6 Kc7 85. Kf7 Kc6 86. Ke6 Kc5 87. Kf5 Kc4 88. Kg4 Rh8 89. Rd7 Rg8+ 90. Kf3 Kc5
+  91. Kf4 Rf8+ 92. Ke5 Kc6 93. Rd2 Re8+ 94. Kf4 Rf8+ 95. Ke5 Kc5 96. Ke4 Kc4 97.
+  Rc2+ Kb3 98. Rc7 Re8+ 99. Kd5 Rd8+ 100. Ke6 Kb4 101. Kf6 Rd1 102. Ke6 Kb5 103.
+  Kf6 Re1 104. Kf5`
+  const moves = pgn.split(/\s*\d+\.\s*|\s+/).slice(1)
+
+  const chess = new Chess()
+  moves.forEach((move) => {
+    expect(chess.isFiftyMoveRule()).toBe(false)
+    chess.move(move)
+  })
+  expect(chess.isFiftyMoveRule()).toBe(true)
+  chess.move('Re5')
+  expect(chess.isFiftyMoveRule()).toBe(true)
+  chess.move('Kxe5')
+  expect(chess.isFiftyMoveRule()).toBe(false)
+})

__tests__/is-fivefold-repetition.test.ts

@@ -0,0 +1,13 @@
+import { Chess } from '../src/chess'
+
+test('isFivefoldRepetition', () => {
+  const moves = 'Nf3 Nf6 Ng1 Ng8 Nf3 Nf6 Ng1 Ng8 Nf3 Nf6 Ng1 Ng8 Nf3 Nf6 Ng1 Ng8'.split(/\s+/)
+  const chess = new Chess()
+  moves.forEach((move) => {
+    expect(chess.isFivefoldRepetition()).toBe(false)
+    chess.move(move)
+  })
+  expect(chess.isFivefoldRepetition()).toBe(true)
+  chess.move('e4')
+  expect(chess.isFivefoldRepetition()).toBe(false)
+})

__tests__/is-seventy-five-move-rule.test.ts

@@ -0,0 +1,31 @@
+import { Chess } from '../src/chess'
+
+test('isSeventyFiveMoveRule', () => {
+  const pgn = `1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 
+  9.c3 Be7 10.Re1 O-O 11.Nbd2 Nc5 12.Bc2 d4 13.Nf1 d3 14.Bb3 Nxb3 15.axb3 Qd7 16.Ng5 Bf5 
+  17.Ng3 Bg6 18.h4 Rfd8 19.Bd2 h6 20.h5 Bf5 21.Nxf5 Qxf5 22.Qf3 Qxf3 23.Nxf3 a5 24.Re4 Rd5 
+  25.Rae1 Rad8 26.g4 Ra8 27.Kg2 Kf8 28.Nd4 Nxd4 29.Rxd4 Rxd4 30.cxd4 Rd8 31.Be3 Rd5 32.Rd1 
+  c5 33.dxc5 Bxc5 34.Bxc5+ Rxc5 35.Rxd3 Rxe5 36.Rd8+ Ke7 37.Ra8 b4 38.Kf3 Rc5 39.Ra7+ Ke6 
+  40.Ke4 Rc2 41.Ra6+ Ke7 42.Rxa5 Rxb2 43.f4 Rxb3 44.Rb5 Rb1 45.g5 b3 46.gxh6 gxh6 47.Kf5 b2
+  48.Rb7+ Ke8 49.Kf6 Rh1 50.Rxb2 Rxh5 51.Rb8+ Kd7 52.Kxf7 Rf5+ 53.Kg6 Rxf4 54.Kxh6 Ke6 
+  55.Rb6+ Kf7 56.Rb7+ Kf6 57.Rb6+ Kf5 58.Rb5+ Kg4 59.Rg5+ Kf3 60.Rb5 Ra4 61.Kg5 Ra1 62.Rb3+
+  Ke4 63.Rb4+ Kd5 64.Rb5+ Kc6 65.Rb2 Kc5 66.Kf4 Kd4 67.Rd2+ Kc3 68.Rd7 Kc2 69.Ke3 Ra3+ 
+  70.Ke4 Ra4+ 71.Ke5 Ra8 72.Ke4 Kc3 73.Kf5 Ra5+ 74.Kg4 Kc4 75.Kh4 Ra4 76.Kh3 Kc5 77.Kh2 
+  Kc6 78.Rd2 Kc5 79.Kh3 Ra3+ 80.Kh4 Kc6 81.Kh5 Kc7 82.Kh6 Kc8 83.Kh7 Rh3+ 84.Kg6 Kc7 85.Kf7
+  Kc6 86.Ke6 Kc5 87.Kf5 Kc4 88.Kg4 Rh8 89.Rd7 Rg8+ 90.Kf3 Kc5 91.Kf4 Rf8+ 92.Ke5 Kc6 93.Rd2 
+  Re8+ 94.Kf4 Rf8+ 95.Ke5 Kc5 96.Ke4 Kc4 97.Rc2+ Kb3 98.Rc7 Re8+ 99.Kd5 Rd8+ 100.Ke6 Kb4 
+  101.Kf6 Rd1 102.Ke6 Kb5 103.Kf6 Re1 104.Kf5 Rd1 105.Rc8 Ka5 106.Kf4 Re1 107.Kg4 Ka4 108.Rb8 
+  Rf1 109.Kg5 Ka3 110.Rc8 Ka2 111.Kh5 Re1 112.Kg5 Ka1 113.Rc7 Rf1 114.Rd7 Kb2 115.Kg6 Re1 116.
+  Rc7 Kb1 117.Kg5 Re2 118.Rc4 Re6 119.Kg4 Kb2 120.Kg3 Ka3 121.Rc2 Re8 122.Kg2 Ka4 123.Rc4+ Ka3 
+  124.Kg1 Re2 125.Rc5 Ka2 126.Kh1 Re1+ 127.Kh2 Ka1 128.Kh3 Rd1 129.Rd5`
+  const moves = pgn.split(/\s*\d+\.\s*|\s+/).slice(1)
+
+  const chess = new Chess()
+  moves.forEach((move) => {
+    expect(chess.isSeventyFiveMoveRule()).toBe(false)
+    chess.move(move)
+  })
+  expect(chess.isSeventyFiveMoveRule()).toBe(true)
+  chess.move('Rxd5')
+  expect(chess.isSeventyFiveMoveRule()).toBe(false)
+})

__tests__/is-threefold-repetition.test.ts

@@ -12,6 +12,8 @@ test('isThreefoldRepetition', () => {
     chess.move(move)
   })
   expect(chess.isThreefoldRepetition()).toBe(true)
+  chess.move('a6')
+  expect(chess.isThreefoldRepetition()).toBe(false)
 })
 
 test('isThreefoldRepetition - 2', () => {
@@ -22,4 +24,6 @@ test('isThreefoldRepetition - 2', () => {
     chess.move(move)
   })
   expect(chess.isThreefoldRepetition()).toBe(true)
+  chess.move('e4')
+  expect(chess.isThreefoldRepetition()).toBe(false)
 })