Allow even money with insurance

src/engine.js

@@ -108,7 +108,7 @@ export const getHandInfo = (playerCards: Array<Card>, dealerCards: Array<Card>,
   const isClosed = hasBusted || hasBlackjack || handValue.hi === 21
   const canDoubleDown = !isClosed && true
   const canSplit = playerCards.length > 1 && playerCards[ 0 ].value === playerCards[ 1 ].value && !isClosed
-  const canInsure = dealerCards[ 0 ].value === 1 && !isClosed
+  const canInsure = dealerCards[0].value === 1 && playerCards.length === 2
   return {
     cards: playerCards,
     playerValue: handValue,
@@ -140,7 +140,7 @@ export const getHandInfoAfterDeal = (playerCards: Array<Card>, dealerCards: Arra
   }
   return {
     ...hand,
-    close: hand.playerHasBlackjack
+    close: hand.playerHasBlackjack && !availableActions.insurance
   }
 }
 
@@ -289,7 +289,7 @@ export const isActionAllowed = (actionName: string, stage: string): boolean => {
   }
 }
 
-export const getPrize = (playerHand: Hand, dealerCards: Array<Card>): number => {
+export const getPrize = (playerHand: Hand, dealerCards: Array<Card>, tookInsurance: boolean): number => {
   const {
     close = false,
     playerHasSurrendered = true,
@@ -309,7 +309,7 @@ export const getPrize = (playerHand: Hand, dealerCards: Array<Card>): number =>
   if (playerHasSurrendered) {
     return bet / 2
   }
-  if (playerHasBlackjack && !dealerHasBlackjack) {
+  if (playerHasBlackjack && (!dealerHasBlackjack || (!dealerHasBlackjack && tookInsurance))) {
     return bet + (bet * 1.5)
   }
   const dealerHasBusted = higherValidDealerValue > 21
@@ -330,7 +330,9 @@ export const getPrizes = ({ history, handInfo: { left, right }, dealerCards }: {
     memo += x.value
     return memo
   }, 0)
-  const wonOnRight = getPrize(right, dealerCards)
+  const insuranceAction = history.find(x => x.type === TYPES.INSURANCE)
+  const tookInsurance = insuranceAction && insuranceAction.payload.bet > 0
+  const wonOnRight = getPrize(right, dealerCards, tookInsurance)
   const wonOnLeft = getPrize(left, dealerCards)
   return {
     finalBet: finalBet,

src/game.js

@@ -157,7 +157,7 @@ export default class Game {
     switch (action.type) {
       case TYPES.DEAL: {
         const { bet, sideBets } = action.payload
-        const { rules: { insurance }, availableBets, history, hits } = this.state
+        const { rules: { insurance, evenMoneyInsurance }, availableBets, history, hits } = this.state
         const playerCards = this.state.deck.splice(this.state.deck.length - 2, 2)
         const dealerCards = this.state.deck.splice(this.state.deck.length - 1, 1)
         const dealerHoleCard = this.state.deck.splice(this.state.deck.length - 1, 1)[ 0 ]
@@ -202,8 +202,13 @@ export default class Game {
           hits: hits + 1
         })
 
-        if (right.playerHasBlackjack) {
-          // purpose of the game archived !!!
+        if (
+          right.playerHasBlackjack &&
+          (!right.availableActions.insurance ||
+            (right.availableActions.insurance &&
+              (!evenMoneyInsurance || dealerValue.lo !== 1)))
+        ) {
+          // purpose of the game achieved !!!
           this._dispatch(actions.showdown())
           break
         }
@@ -214,7 +219,7 @@ export default class Game {
           }
         // else
         // in this case, the game must continue in "player-turn-right"
-        // waiting for the insurance action
+        // waiting for the insurance action, including even money if enabled
         }
         break
       }
@@ -227,7 +232,8 @@ export default class Game {
         const insurancePrize = (isFirstCardAce && dealerHasBlackjack && insuranceValue > 0 && bet > 0) ? insuranceValue * 3 : 0
         const right = this.enforceRules(engine.getHandInfoAfterInsurance(handInfo.right.cards, dealerCards))
         right.bet = initialBet
-        right.close = dealerHasBlackjack
+        const tookEvenMoney = insuranceValue > 0 && handInfo.right.playerHasBlackjack
+        right.close = dealerHasBlackjack || tookEvenMoney
         const historyItem = appendEpoch({
           ...action,
           payload: { bet: insuranceValue || 0 }
@@ -244,7 +250,7 @@ export default class Game {
             }
           }
         })
-        if (dealerHasBlackjack) {
+        if (dealerHasBlackjack || tookEvenMoney) {
           this._dispatch(actions.showdown())
         }
         break

src/presets.js

@@ -39,6 +39,7 @@ export const getRules = ({
   doubleAfterSplit = true,
   surrender = true,
   insurance = true,
+  evenMoneyInsurance = false,
   showdownAfterAceSplit = true
 }: Rule) => {
   return {
@@ -49,6 +50,7 @@ export const getRules = ({
     doubleAfterSplit: doubleAfterSplit,
     surrender: surrender,
     insurance: insurance,
+    evenMoneyInsurance: evenMoneyInsurance,
     showdownAfterAceSplit: showdownAfterAceSplit
   }
 }

src/types/index.js

@@ -56,6 +56,7 @@ export type Rule = {
   split: boolean,
   surrender: boolean,
   insurance: boolean,
+  evenMoneyInsurance: boolean,
   showdownAfterAceSplit: boolean
 }
 

test/game.spec.js

@@ -303,6 +303,115 @@ describe('Game flow', function () {
     assert.equal(wonOnLeft, 20, 'won 20 on left')
     assert.equal(wonOnRight, 20, 'won 20 on right')
   })
+  describe('# even money dealer BJ', () => {
+    const test = {
+      cards: '♦10 ♥1 ♠10 ♠1'
+    }
+    it(`INSURANCE ON AND EVEN_MONEY ON ${
+      test.cards
+    }, insure YES, and finish`, () => {
+      const testActions = ['restore', 'deal', 'insuranceYes']
+      const rules = { insurance: true, evenMoneyInsurance: true }
+      const state = executeFlow(
+        rules,
+        test.cards,
+        testActions.map(x => functions[x])
+      )
+      const {
+        finalBet,
+        wonOnRight,
+        handInfo: { right },
+        sideBetsInfo: {
+          insurance: { win }
+        }
+      } = state
+      assert.equal(
+        state.stage,
+        'done',
+        'blackjack but insurance is ON and first card is ♥1'
+      )
+      assert.equal(finalBet, 15, 'bet 10 and insurance 5')
+      assert.equal(right.close, true, 'right hand should be close')
+      assert.equal(
+        win,
+        5 * 3,
+        'insurance pays 2 to 1 when dealer has bj + insurance value'
+      )
+      assert.equal(
+        wonOnRight,
+        10,
+        "right has prize because it's a push (even money)"
+      )
+    })
+    it(`INSURANCE ON AND EVEN_MONEY OFF ${
+      test.cards
+    }, insure YES, and finish`, () => {
+      const testActions = ['restore', 'deal']
+      const rules = { insurance: true, evenMoneyInsurance: false }
+      const state = executeFlow(
+        rules,
+        test.cards,
+        testActions.map(x => functions[x])
+      )
+      const {
+        sideBetsInfo: { insurance }
+      } = state
+      assert.equal(insurance, undefined, 'insurance not offered')
+    })
+  })
+  describe('# even money dealer no BJ', () => {
+    it(`INSURANCE ON AND EVEN_MONEY ON`, () => {
+      const testActions = ['restore', 'deal', 'insuranceYes']
+      const rules = { insurance: true, evenMoneyInsurance: true }
+      const state = executeFlow(
+        rules,
+        '♦5 ♥1 ♠10 ♠1',
+        testActions.map(x => functions[x])
+      )
+      const bet = 10
+      const maxInsuranceAmount = bet / 2
+      const {
+        finalBet,
+        wonOnRight,
+        handInfo: { right },
+        sideBetsInfo: {
+          insurance: { risk, win }
+        }
+      } = state
+      assert.equal(
+        state.stage,
+        'done',
+        'blackjack but insurance is ON and first card is ♥1'
+      )
+      assert.equal(right.playerValue.hi, 21, 'player value must be 4')
+      assert.equal(
+        finalBet,
+        bet + maxInsuranceAmount,
+        `bet ${bet} and max insurance ${maxInsuranceAmount}`
+      )
+      assert.equal(right.close, true, 'right hand should be close')
+      assert.equal(risk, 5, 'insurance risk value is 5')
+      assert.equal(win, 0, 'insurance win value is 0')
+      assert.equal(
+        wonOnRight,
+        bet + bet * 1.5,
+        "right has prize because it's a player blackjack (even money)"
+      )
+    })
+    it(`INSURANCE ON AND EVEN_MONEY OFF`, () => {
+      const testActions = ['restore', 'deal']
+      const rules = { insurance: true, evenMoneyInsurance: false }
+      const state = executeFlow(
+        rules,
+        '♦5 ♥1 ♠10 ♠1',
+        testActions.map(x => functions[x])
+      )
+      const {
+        sideBetsInfo: { insurance }
+      } = state
+      assert.equal(insurance, undefined, 'insurance not offered')
+    })
+  })
 })
 
 describe('Must Stand on 17', function () {
@@ -468,4 +577,4 @@ describe('No matter how many aces ... soft hands do not busts', () => {
     assert.equal(playerHasBusted, false, 'Player should be 12 not 22')
     assert.equal(wonOnRight, 0, 'player lose. dealer has 21, player 12 or 22')
   })
-})
+})

types/index.d.ts

@@ -91,6 +91,7 @@ declare module 'engine-blackjack' {
         split: boolean;
         surrender: boolean;
         insurance: boolean;
+        evenMoneyInsurance: boolean;
         showdownAfterAceSplit: boolean;
     }