JoshHeaps.Net/tests/holdem/messyTables.test.js

// Home games are messy. People walk up mid-hand, storm off mid-hand, argue about
// whose blind it is, and pass the button round three times before anyone deals.
// These are the cases the positional rules quietly get wrong.
const { test, describe } = require("node:test");
const assert = require("node:assert/strict");
const { Betting, HoldemState, PotCalculator, Money, makeTable, chipsOnTable, contributions } = require("./load");

const potOf = state => HoldemState.totalPot(state);

describe("a player leaves in the middle of a hand", () => {
    test("their chips stay in the pot", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.call(state, 3); Betting.call(state, 0); Betting.call(state, 1); Betting.check(state, 2);
        Betting.sweepToHandTotals(state);

        const before = potOf(state);
        assert.equal(before, 8);

        state.seats[1].inHand = false; // dealer takes them out

        assert.equal(potOf(state), before, "the pot must not shrink when a player is taken out");
    });

    test("they cannot be paid out of a pot they walked away from", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.call(state, 0); Betting.call(state, 1); Betting.check(state, 2);
        Betting.sweepToHandTotals(state);

        state.seats[1].inHand = false;

        const players = state.seats
            .filter(p => HoldemState.computeContribution(p, state.chipLegend, state.basePotAmount) > 0)
            .map(p => ({
                id: p.id,
                contribution: HoldemState.computeContribution(p, state.chipLegend, state.basePotAmount),
                folded: p.folded || HoldemState.isDeadMoney(p),
            }));

        const layers = PotCalculator.layers(players);
        assert.ok(!layers[0].eligible.includes(state.seats[1].id), "a departed player can't win");
        assert.equal(layers.reduce((s, l) => s + l.amount, 0), 6, "but their money is still being played for");
    });

    test("taking out the player who is to act moves the action on", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        const acting = state.actingSeatIndex;

        state.seats[acting].inHand = false;
        Betting.passAction(state, acting);

        assert.notEqual(state.actingSeatIndex, acting, "the table can't wait on somebody who left");
        assert.ok(state.actingSeatIndex === null || state.seats[state.actingSeatIndex].inHand);
    });

    test("an empty chair still contributes nothing, base pot or not", () => {
        // The table-wide default must not be read as an ante from seats nobody is in.
        const state = makeTable({ seatCount: 6, seated: [0, 1], dealerSeatIndex: 0 });
        state.basePotAmount = 25;
        assert.equal(HoldemState.computeContribution(state.seats[4], state.chipLegend, 25), 0);
    });
});

describe("a player joins in the middle of a hand", () => {
    test("they sit the hand out rather than joining a pot they never paid into", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.call(state, 0); Betting.call(state, 1); Betting.check(state, 2);
        Betting.sweepToHandTotals(state);

        // Walks up and is dealt in — the app marks them folded for this hand.
        state.seats[4].inHand = true;
        state.seats[4].stack = 100;
        state.seats[4].folded = true;

        assert.ok(!Betting.liveSeats(state).some(s => s.index === 4), "not live this hand");
        assert.equal(HoldemState.computeContribution(state.seats[4], state.chipLegend, state.basePotAmount), 0);
    });

    test("they are a full player again on the next hand", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        state.seats[4].inHand = true;
        state.seats[4].stack = 100;
        state.seats[4].folded = true;

        HoldemState.startNextHand(state);
        Betting.beginHand(state);

        assert.equal(state.seats[4].folded, false);
        assert.ok(Betting.liveSeats(state).some(s => s.index === 4), "dealt in like anyone else");
    });
});

describe("passing the button around before the cards come out", () => {
    test("moving the button re-posts the blinds and keeps the chip count straight", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        const startingChips = chipsOnTable(state);
        Betting.beginHand(state);

        assert.equal(state.seats[1].committed, 1);
        assert.equal(state.seats[2].committed, 2);

        state.dealerSeatIndex = 2;
        Betting.repostBlinds(state);

        assert.equal(state.seats[1].committed, 0, "the old small blind got their chip back");
        assert.equal(state.seats[3].committed, 1, "and the new one has posted");
        assert.equal(state.seats[0].committed, 2);
        assert.equal(chipsOnTable(state), startingChips, "no chips created or lost in the shuffle");
    });

    test("passing it round many times still balances", () => {
        const state = makeTable({ seatCount: 8, seated: [0, 2, 3, 5, 7], dealerSeatIndex: 0 });
        const startingChips = chipsOnTable(state);
        Betting.beginHand(state);

        [2, 5, 7, 3, 0, 5].forEach(seat => {
            state.dealerSeatIndex = seat;
            Betting.repostBlinds(state);
            assert.equal(chipsOnTable(state), startingChips, `chips drifted after passing to seat ${seat}`);
        });

        const { sbIndex, bbIndex } = HoldemState.getBlindSeats(state);
        assert.equal(Betting.committed(state.seats[sbIndex]), 1);
        assert.equal(Betting.committed(state.seats[bbIndex]), 2);
    });

    test("once somebody has acted, the blinds are settled", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        assert.equal(Betting.onlyBlindsIn(state), true, "nothing but blinds so far");

        Betting.call(state, 3);
        assert.equal(Betting.onlyBlindsIn(state), false, "a call means the blinds are set where they are");
    });
});

describe("naming the blinds by hand", () => {
    test("a named blind wins over the button order", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        state.blindOverride = { sbIndex: 3, bbIndex: 0 };

        const { sbIndex, bbIndex, manual } = HoldemState.getBlindSeats(state);
        assert.equal(sbIndex, 3);
        assert.equal(bbIndex, 0);
        assert.equal(manual, true);

        Betting.beginHand(state);
        assert.equal(state.seats[3].committed, 1);
        assert.equal(state.seats[0].committed, 2);
        assert.equal(state.seats[1].committed, 0, "the positional small blind posts nothing");
    });

    test("a named blind on a player who isn't dealt in is ignored", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        state.blindOverride = { sbIndex: 4, bbIndex: 0 }; // seat 4 is an empty chair

        const { sbIndex, manual } = HoldemState.getBlindSeats(state);
        assert.ok(!manual, "falls back to the button order rather than posting to nobody");
        assert.ok(state.seats[sbIndex].inHand);
    });

    test("both blinds on one player is refused", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        state.blindOverride = { sbIndex: 1, bbIndex: 1 };
        const { sbIndex, bbIndex } = HoldemState.getBlindSeats(state);
        assert.notEqual(sbIndex, bbIndex);
    });

    test("naming blinds heads-up still acts in the right order", () => {
        const state = makeTable({ seatCount: 6, seated: [2, 5], dealerSeatIndex: 2 });
        state.blindOverride = { sbIndex: 5, bbIndex: 2 }; // deliberately the reverse

        Betting.beginHand(state);
        assert.equal(state.seats[5].committed, 1);
        assert.equal(state.seats[2].committed, 2);
        assert.equal(state.actingSeatIndex, 5, "the small blind acts first pre-flop heads-up");

        Betting.call(state, 5);
        Betting.check(state, 2);
        Betting.closeStreet(state);
        assert.equal(state.actingSeatIndex, 2, "and the big blind leads after the flop");
    });

    test("the naming only lasts the hand it was made for", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        state.blindOverride = { sbIndex: 3, bbIndex: 0 };
        Betting.beginHand(state);

        HoldemState.startNextHand(state);
        assert.equal(state.blindOverride, null, "blinds go back to following the button");
    });
});

describe("the first hand on a fresh table", () => {
    test("the button never starts on an empty chair", () => {
        const state = HoldemState.createDefault();
        HoldemState.resizeSeats(state, 9);
        [4, 6, 7].forEach(i => { state.seats[i].inHand = true; state.seats[i].stack = 100; });
        assert.equal(state.dealerSeatIndex, 0, "a fresh table starts the button on seat 1");
        assert.equal(state.seats[0].inHand, false, "which nobody is sitting in");

        Betting.beginHand(state);

        assert.ok(state.seats[state.dealerSeatIndex].inHand, "the button moved to a real player");
        const { sbIndex, bbIndex } = HoldemState.getBlindSeats(state);
        assert.ok(state.seats[sbIndex].inHand);
        assert.ok(state.seats[bbIndex].inHand);
        assert.notEqual(sbIndex, bbIndex);
    });

    test("a table that empties out around the button recovers", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 3 });
        state.seats[3].inHand = false; // the player holding the button leaves
        HoldemState.ensureButtonOnPlayer(state);
        assert.ok(state.seats[state.dealerSeatIndex].inHand);
    });

    test("two players left after everyone else walks is heads-up, blinds reversed", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        [2, 3].forEach(i => { state.seats[i].inHand = false; });

        HoldemState.startNextHand(state);
        Betting.beginHand(state);

        const { sbIndex, headsUp } = HoldemState.getBlindSeats(state);
        assert.equal(headsUp, true);
        assert.equal(sbIndex, state.dealerSeatIndex, "heads-up the button posts the small blind");
    });
});

describe("chips survive a messy table", () => {
    test("joining, leaving and passing the button never changes the chip count", () => {
        const state = makeTable({ seatCount: 8, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        state.seats[6].stack = 100; // sitting down but not dealt in yet
        const startingChips = chipsOnTable(state);

        Betting.beginHand(state);
        state.dealerSeatIndex = 2;
        Betting.repostBlinds(state);

        state.seats[6].inHand = true;   // walks up mid-hand
        state.seats[6].folded = true;
        assert.equal(chipsOnTable(state), startingChips);

        Betting.call(state, state.actingSeatIndex);
        state.seats[1].inHand = false;  // and someone storms off
        Betting.sweepToHandTotals(state);

        assert.equal(chipsOnTable(state), startingChips, "every chip is still accounted for");
        assert.equal(
            Money.toCents(potOf(state) + state.seats.reduce((s, p) => s + (Number(p.stack) || 0), 0)),
            Money.toCents(startingChips),
            "and the pot plus the stacks is the whole table"
        );
    });
});