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

// The house's cut.
//
// A game that rakes has chips leaving the table every hand, and the bank check used to
// call them missing: buy-ins in, chips on the felt, and a dealer told somebody had been
// paid for chips they never got. The cut is the one thing here that is supposed to go
// and not come back.
const test = require("node:test");
const { describe } = require("node:test");
const assert = require("node:assert");
const { Money, HoldemState, Betting, makeTable, chipsOnTable } = require("./load");

const raking = (rake, extra = {}) => {
    const state = makeTable({ seatCount: 6, stack: 200, ...extra });
    state.rake = { percent: 0, cap: null, noFlopNoDrop: true, ...rake };
    return state;
};

describe("what the house takes", () => {
    test("nothing, unless somebody says otherwise", () => {
        const state = makeTable({ seatCount: 6 });
        assert.equal(state.rake.percent, 0);
        assert.equal(HoldemState.rakeOn(state, 100), 0);
    });

    test("a percentage of the pot", () => {
        assert.equal(HoldemState.rakeOn(raking({ percent: 5 }), 100), 5);
        assert.equal(HoldemState.rakeOn(raking({ percent: 10 }), 60), 6);
    });

    test("no more than the cap", () => {
        const state = raking({ percent: 5, cap: 5 });
        assert.equal(HoldemState.rakeOn(state, 100), 5);
        assert.equal(HoldemState.rakeOn(state, 400), 5, "still five on a pot four times the size");
        assert.equal(HoldemState.rakeOn(state, 40), 2, "under the cap it is just the percentage");
    });

    test("no flop, no drop", () => {
        const state = raking({ percent: 5 });
        assert.equal(HoldemState.rakeOn(state, 100, false), 0, "hand ended before the flop");
        assert.equal(HoldemState.rakeOn(state, 100, true), 5);
    });

    test("unless the house rakes every pot", () => {
        const state = raking({ percent: 5, noFlopNoDrop: false });
        assert.equal(HoldemState.rakeOn(state, 100, false), 5);
    });

    test("nothing it can't make out of the table's chips, rounded the players' way", () => {
        // 5% of $30 is $1.50, and this table's smallest chip is a dollar.
        const state = raking({ percent: 5 });
        assert.equal(HoldemState.rakeOn(state, 30), 1);
        // 5% of $10 is 50c — under a chip, so the house takes nothing at all.
        assert.equal(HoldemState.rakeOn(state, 10), 0);
    });

    test("never more than the pot, whatever gets typed in", () => {
        assert.equal(HoldemState.rakeOn(raking({ percent: 100 }), 20), 20);
        assert.equal(HoldemState.rakeOn(raking({ percent: 5, cap: 500 }), 20), 1);
    });

    test("nothing out of an empty pot", () => {
        assert.equal(HoldemState.rakeOn(raking({ percent: 5 }), 0), 0);
    });
});

describe("taking it out of the pot", () => {
    const winner = amount => [{ id: "a", label: "Ann", amount }];

    test("one winner just gets the pot less the cut", () => {
        const { payouts, rake } = HoldemState.applyRake(winner(100), 5);
        assert.equal(rake, 5);
        assert.deepEqual(payouts.map(p => p.amount), [95]);
    });

    test("a split pot shares what's left, in proportion", () => {
        const { payouts } = HoldemState.applyRake(
            [{ id: "a", label: "Ann", amount: 60 }, { id: "b", label: "Ben", amount: 40 }], 10);
        assert.deepEqual(payouts.map(p => p.amount), [54, 36]);
    });

    test("the rounding leftovers go back to the players, not to the house", () => {
        // $100 split three ways less $7: 93 doesn't divide evenly, and every cent of
        // it has to land on somebody.
        const { payouts, rake } = HoldemState.applyRake([
            { id: "a", label: "Ann", amount: 34 },
            { id: "b", label: "Ben", amount: 33 },
            { id: "c", label: "Cal", amount: 33 },
        ], 7);
        assert.equal(rake, 7);
        assert.equal(Money.round(payouts.reduce((sum, p) => sum + p.amount, 0)), 93);
    });

    test("what goes out plus what the house keeps is what was in the middle", () => {
        [[100, 5], [37.5, 1.25], [1000, 0], [9, 9]].forEach(([pot, rake]) => {
            const result = HoldemState.applyRake(winner(pot), rake);
            assert.equal(Money.round(result.payouts[0].amount + result.rake), pot, `${pot} less ${rake}`);
        });
    });

    test("asking for more than the pot takes the pot, not more", () => {
        const { payouts, rake } = HoldemState.applyRake(winner(20), 50);
        assert.equal(rake, 20);
        assert.deepEqual(payouts.map(p => p.amount), [0]);
    });

    test("no rake, no change — the same payouts come back", () => {
        const { payouts, rake } = HoldemState.applyRake(winner(80), 0);
        assert.equal(rake, 0);
        assert.deepEqual(payouts.map(p => p.amount), [80]);
    });
});

describe("what the box is checked against", () => {
    test("raked chips are gone but not missing", () => {
        const state = raking({ percent: 5 });
        state.seats.forEach(p => { p.buyIns = 200; });
        const before = HoldemState.bankReconciliation(state);
        assert.equal(before.balanced, true);

        // The house takes $10 out of the middle: somebody's stack is $10 lighter.
        state.seats[0].stack = 190;
        state.rakeTaken = 10;
        const after = HoldemState.bankReconciliation(state);
        assert.equal(after.raked, 10);
        assert.equal(after.balanced, true, "the check still balances");
    });

    test("and are told apart from the ones that went astray", () => {
        const state = raking({ percent: 5 });
        state.seats.forEach(p => { p.buyIns = 200; });
        state.seats[0].stack = 180;
        state.rakeTaken = 10;
        const check = HoldemState.bankReconciliation(state);
        assert.equal(check.raked, 10);
        assert.equal(check.difference, -10, "ten dollars really are missing");
        assert.equal(check.balanced, false);
    });

    test("a table that has never raked reads exactly as it did before", () => {
        const state = makeTable({ seatCount: 6 });
        state.seats.forEach(p => { p.buyIns = 100; p.stack = 100; });
        const check = HoldemState.bankReconciliation(state);
        assert.equal(check.raked, 0);
        assert.equal(check.balanced, true);
    });
});

describe("the record of it", () => {
    test("the hand log keeps the pot as the table saw it, and the cut beside it", () => {
        const state = raking({ percent: 5 });
        HoldemState.recordHand(state, [{ id: state.seats[0].id, label: "P1", amount: 95 }], 5);
        const [entry] = state.handHistory;
        assert.equal(entry.pot, 100, "the pot in the middle");
        assert.equal(entry.rake, 5);
        assert.equal(entry.payouts[0].amount, 95, "what the winner actually took");
    });

    test("a hand with no rake records a zero rather than nothing", () => {
        const state = makeTable({ seatCount: 6 });
        HoldemState.recordHand(state, [{ id: state.seats[0].id, label: "P1", amount: 40 }]);
        assert.equal(state.handHistory[0].rake, 0);
        assert.equal(state.handHistory[0].pot, 40);
    });

    test("a table saved before the house took anything takes nothing", () => {
        const parsed = JSON.parse(JSON.stringify(makeTable({ seatCount: 6 })));
        delete parsed.rake;
        delete parsed.rakeTaken;
        const migrated = HoldemState.migrate(parsed);
        assert.equal(migrated.rake.percent, 0);
        assert.equal(migrated.rake.noFlopNoDrop, true);
        assert.equal(migrated.rakeTaken, 0);
    });

    test("nonsense in a saved rake is cleaned up rather than trusted", () => {
        const parsed = JSON.parse(JSON.stringify(makeTable({ seatCount: 6 })));
        parsed.rake = { percent: -5, cap: -1, noFlopNoDrop: false };
        parsed.rakeTaken = -20;
        const migrated = HoldemState.migrate(parsed);
        assert.equal(migrated.rake.percent, 0);
        assert.equal(migrated.rake.cap, null);
        assert.equal(migrated.rake.noFlopNoDrop, false, "that one is a real choice");
        assert.equal(migrated.rakeTaken, 0);
    });
});

describe("the file the dealer hands over", () => {
    const { HandHistoryExport } = require("./load");

    test("has a column for what the house took", () => {
        const state = raking({ percent: 5 });
        HoldemState.recordHand(state, [{ id: "a", label: "Ann", amount: 95 }], 5);
        HoldemState.recordHand(state, [{ id: "b", label: "Ben", amount: 40 }], 0);

        // Oldest hand first, and money as bare numbers so a spreadsheet can total it.
        const csv = HandHistoryExport.toCsv(state.handHistory);
        const [header, raked, unraked] = csv.split("\n");
        assert.match(header, /Pot,House take,Payouts/);
        assert.match(raked, /,100\.00,5\.00,/, "the raked hand says how much was taken");
        assert.match(unraked, /,40\.00,0\.00,/, "and the unraked one says nothing was");
    });
});

describe("a raked hand, end to end", () => {
    test("the chips add up: stacks plus the house's cut equal what was bought in", () => {
        // 5/10 blinds, so six callers make a pot big enough for 5% to be a whole chip.
        // At 1/2 the same hand makes $12, 5% of which is 60c and rounds away to
        // nothing — which is the rule working, not a hand worth testing the bank on.
        const state = raking({ percent: 5, cap: 5 }, { smallBlind: 5, bigBlind: 10 });
        state.seats.forEach(p => { p.buyIns = 200; });
        Betting.beginHand(state);
        // Everyone calls the big blind, then it is checked down.
        state.seats.forEach((p, i) => { if (p.inHand) Betting.putIn(state, i, Betting.toCall(state, p)); });
        Betting.sweepToHandTotals(state);

        const pot = state.seats.reduce((sum, p) => sum + (Number(p.amountOverride) || 0), 0);
        const rake = HoldemState.rakeOn(state, pot, true);
        assert.equal(pot, 60);
        assert.equal(rake, 3);

        const { payouts } = HoldemState.applyRake([{ id: state.seats[0].id, label: "P1", amount: pot }], rake);
        state.rakeTaken = rake;
        HoldemState.recordHand(state, payouts, rake);
        Betting.creditWinnings(state, payouts);
        HoldemState.startNextHand(state);

        assert.equal(Money.round(chipsOnTable(state) + state.rakeTaken), 1200);
        assert.equal(HoldemState.bankReconciliation(state).balanced, true);
    });
});