omaha hold'em

package.json

@@ -28,5 +28,8 @@
   },
   "engines": [
     "node >= 4.0.0"
-  ]
+  ],
+  "dependencies": {
+    "percom": "^1.1.3"
+  }
 }

pokersolver.js

@@ -4,6 +4,8 @@
  * http://goldfirestudios.com
  */
 
+var percom = require('percom');
+
 (function() {
   'use strict';
 
@@ -1824,10 +1826,52 @@
     }
   }
 
+  class OmahaGame {
+    /**
+     * Build and return the best hand for Omaha Hold'em.
+     * @param  {Array} boardCards Array of board cards (['Ad', '3c', 'Th', ...]).
+     * @param  {Array} playerCards Array of player's cards (['Ad', '3c', 'Th', ...]).
+     * @return {Hand}       Best hand.
+     */
+    static solve(boardCards, playerCards) {
+      const game = new Game('standard');
+
+      var boardCombinations = percom.com(boardCards, 3);
+      var playerCombinations = percom.com(playerCards, 2);
+      var allCombinations = boardCombinations.reduce(function (res, b) {
+        return res.concat(
+          playerCombinations.map(function (p) {
+            return b.concat(...p);
+          })
+        );
+      }, []);
+
+      var hands = game.handValues;
+      var result = null;
+
+      for (var j = 0; j < allCombinations.length; j++) {
+        var combinationResult = null;
+        var cards = allCombinations[j];
+        for (var i = 0; i < hands.length; i++) {
+          combinationResult = new hands[i](cards, game);
+          if (combinationResult.isPossible) {
+            break;
+          }
+        }
+        if (!result || result.compare(combinationResult) > 0) {
+          result = combinationResult;
+        }
+      }
+
+      return result;
+    }
+  }
+
   function exportToGlobal(global) {
     global.Card = Card;
     global.Hand = Hand;
     global.Game = Game;
+    global.OmahaGame = OmahaGame;
     global.RoyalFlush = RoyalFlush;
     global.NaturalRoyalFlush = NaturalRoyalFlush;
     global.WildRoyalFlush = WildRoyalFlush;

test/omaha.js

@@ -0,0 +1,190 @@
+var Flush = require('../pokersolver').Flush;
+var StraightFlush = require('../pokersolver').StraightFlush;
+var Straight = require('../pokersolver').Straight;
+var FourOfAKind = require('../pokersolver').FourOfAKind;
+var FullHouse = require('../pokersolver').FullHouse;
+var ThreeOfAKind = require('../pokersolver').ThreeOfAKind;
+var TwoPair = require('../pokersolver').TwoPair;
+var OnePair = require('../pokersolver').OnePair;
+var OmahaGame = require('../pokersolver').OmahaGame;
+
+describe('A basic hand', function () {
+  var boardCards = ['As', '4h', 'Kd', '3h', '5h'];
+  var playerCards = ['Ah', 'Ks', '4d', '2h'];
+  it('should return a hand with cards sorted descending', function () {
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    hand.cardPool[0].toString().should.equal('Ah');
+    return hand.cardPool[4].toString().should.equal('2h');
+  });
+  it('should return a correct description', function () {
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.descr.should.equal('Straight Flush, 5h High');
+  });
+  return it('should return throw an Error for a hand with duplicate cards', function () {
+    (function () {
+      var playerCards = ['As', 'Ah', 'Ks', '4d'];
+      OmahaGame.solve(boardCards, playerCards);
+    }.should.throw());
+  });
+});
+
+describe('A Straight Flush', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['As', '4h', 'Kd', '3h', '5h'];
+    var playerCards = ['Ah', 'Ks', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(StraightFlush);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['Ah', '4h', 'Kd', '3h', '5h'];
+    var playerCards = ['As', 'Ks', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(StraightFlush);
+  });
+  return it('should return 5 cards with low ace', function () {
+    var boardCards = ['Ah', '4h', 'Kd', '3h', '5h'];
+    var playerCards = ['As', 'Ks', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.cards.length.should.equal(5);
+  });
+});
+
+describe('A Four of a Kind', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['Ah', '4h', 'Kd', 'Ad', '5h'];
+    var playerCards = ['As', 'Ac', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(FourOfAKind);
+  });
+  return it('should be detected as not possible', function () {
+    var boardCards = ['Ah', '4h', 'Kd', '4d', '5h'];
+    var playerCards = ['As', 'Ac', 'Ad', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(FourOfAKind);
+  });
+});
+
+describe('A Full House', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['Ah', '4h', '5d', 'Kd', '5h'];
+    var playerCards = ['As', '5c', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    hand.should.be.an.instanceOf(FullHouse);
+
+    boardCards = ['Ah', '4h', '5d', 'Ad', '7h'];
+    playerCards = ['As', '5c', '4d', '2h'];
+    hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(FullHouse);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['2h', 'Ac', '4d', 'Kd', '5h'];
+    var playerCards = ['As', '5c', '5d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(FullHouse);
+  });
+  it('should pick the high kickers', function () {
+    var boardCards = ['Ah', '4h', '5d', 'Ad', '7h'];
+    var playerCards = ['As', '5c', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.cards.toString().indexOf('4h').should.equal(-1);
+  });
+  return it('should be in order', function () {
+    var boardCards = ['Ah', '4h', '5d', 'Ad', '7h'];
+    var playerCards = ['As', '5c', '4d', '2h'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.cards.toString().should.equal('Ah,Ad,As,5d,5c');
+  });
+});
+
+describe('A Flush', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['2h', 'Ac', '4d', 'Kh', '5h'];
+    var playerCards = ['As', '4h', '5d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(Flush);
+  });
+  return it('should be detected as not possible', function () {
+    var boardCards = ['2h', 'Ac', '4d', 'Kh', '5d'];
+    var playerCards = ['As', '4h', '5h', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(Flush);
+  });
+});
+
+describe('A Straight', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '5h'];
+    var playerCards = ['7s', '6c', '5d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(Straight);
+  });
+  it('should be detected as possible', function () {
+    var boardCards = ['9h', 'Jc', '4d', 'Th', '5h'];
+    var playerCards = ['As', '7c', '8d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(Straight);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['3h', '3c', '4d', 'Kh', '4h'];
+    var playerCards = ['7s', '6c', '5d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(Straight);
+  });
+  it('should detect a low ace', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '5h'];
+    var playerCards = ['7s', '7c', '5d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(Straight);
+  });
+  it('should detect a high ace', function () {
+    var boardCards = ['2h', 'Jc', '4d', 'Kh', 'Ah'];
+    var playerCards = ['7s', 'Tc', 'Qd', 'As'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(Straight);
+  });
+});
+
+describe('Three of a Kind', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '7h'];
+    var playerCards = ['7s', '7c', '8d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(ThreeOfAKind);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '5h'];
+    var playerCards = ['7s', '7c', '7d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(ThreeOfAKind);
+  });
+});
+
+describe('Two Pair', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['2h', 'Jc', '4d', '8h', '8d'];
+    var playerCards = ['7s', '7c', '9d', 'Ah'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(TwoPair);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '5h'];
+    var playerCards = ['7s', '7c', '5d', 'Jh'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(TwoPair);
+  });
+});
+
+describe('One Pair', function () {
+  it('should be detected as possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '8h'];
+    var playerCards = ['Js', 'Qc', '8d', 'Ac'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.be.an.instanceOf(OnePair);
+  });
+  it('should be detected as not possible', function () {
+    var boardCards = ['2h', '3c', '4d', 'Kh', '7h'];
+    var playerCards = ['Js', 'Qc', '8d', 'Ac'];
+    var hand = OmahaGame.solve(boardCards, playerCards);
+    return hand.should.not.be.an.instanceOf(OnePair);
+  });
+});

test/test.js

@@ -1,18 +1,19 @@
 var should = require('should');
 
 function importTest(name, path) {
-  describe(name, function() {
+  describe(name, function () {
     require(path);
   });
 }
 
-describe('main', function() {
+describe('main', function () {
   importTest('Standard', './standard');
+  importTest('Omaha', './omaha');
   importTest('Jacks or Better', './jacksbetter');
   importTest('Joker Poker', './joker');
   importTest('Deuces Wild', './deuceswild');
   importTest('Three Card Poker', './threecard');
   importTest('Four Card Poker', './fourcard');
   importTest('Four Card Aces Up Bonus', './fourcardbonus');
-  return importTest('Pai Gow Poker', './paigowpokerfullhands');
+  importTest('Pai Gow Poker', './paigowpokerfullhands');
 });