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

const { test, describe } = require("node:test");
const assert = require("node:assert/strict");
const { Betting, makeTable, chipsOnTable } = require("./load");

describe("Betting.beginHand", () => {
    test("blinds are posted and the seat after the big blind acts first", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0, smallBlind: 1, bigBlind: 2 });
        Betting.beginHand(state);

        assert.equal(state.seats[1].committed, 1, "small blind");
        assert.equal(state.seats[2].committed, 2, "big blind");
        assert.equal(state.currentBet, 2);
        assert.equal(state.actingSeatIndex, 3, "under the gun");
    });

    test("heads-up, the button posts the small blind and acts first pre-flop", () => {
        const state = makeTable({ seatCount: 6, seated: [2, 5], dealerSeatIndex: 2 });
        Betting.beginHand(state);

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

    test("heads-up, the big blind acts first once the flop is out", () => {
        const state = makeTable({ seatCount: 6, seated: [2, 5], dealerSeatIndex: 2 });
        Betting.beginHand(state);
        Betting.call(state, 2);
        Betting.check(state, 5);
        Betting.closeStreet(state);

        assert.equal(state.street, "flop");
        assert.equal(state.actingSeatIndex, 5, "the big blind is first to act after the flop");
    });

    test("a blind bigger than a stack puts that player all-in without stalling the action", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1], dealerSeatIndex: 0, smallBlind: 50, bigBlind: 100 });
        state.seats[0].stack = 10; // can't cover the small blind

        Betting.beginHand(state);
        assert.equal(state.seats[0].stack, 0, "all-in for what they had");
        assert.equal(state.seats[0].committed, 10);
        assert.notEqual(state.actingSeatIndex, 0, "a player with no chips has nothing to decide");
    });

    test("posting blinds never invents or destroys chips", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], stack: 100 });
        const before = chipsOnTable(state);
        Betting.beginHand(state);
        assert.equal(chipsOnTable(state), before);
    });
});

describe("Betting street completion", () => {
    test("a street ends once everyone has matched the bet and had a turn", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);

        Betting.call(state, 3);
        Betting.call(state, 0);
        Betting.call(state, 1);
        assert.equal(Betting.isStreetComplete(state), false, "the big blind still has an option");

        Betting.check(state, 2);
        assert.equal(Betting.isStreetComplete(state), true);
        assert.equal(state.actingSeatIndex, null);
    });

    test("a raise reopens the action for everyone who had already called", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);

        Betting.call(state, 3);
        Betting.call(state, 0);
        assert.equal(state.seats[3].hasActed, true);

        Betting.raiseTo(state, 1, 10);
        assert.equal(state.seats[3].hasActed, false, "seat 3 owes a response again");
        assert.equal(state.seats[0].hasActed, false);
        assert.equal(state.currentBet, 10);
        assert.equal(Betting.isStreetComplete(state), false);
    });

    test("the action skips a player who is all-in but still in the hand", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        state.seats[3].stack = 5;
        Betting.beginHand(state);

        Betting.allIn(state, 3);
        assert.equal(state.seats[3].stack, 0);
        assert.notEqual(state.actingSeatIndex, 3);
        // They are still live and can still win the pot.
        assert.ok(Betting.liveSeats(state).some(s => s.index === 3));
    });

    test("closing a street sweeps chips into hand totals and resets the bet", () => {
        const state = makeTable({ seatCount: 4, 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);

        const before = chipsOnTable(state);
        Betting.closeStreet(state);

        assert.equal(state.currentBet, 0);
        assert.equal(state.street, "flop");
        assert.equal(chipsOnTable(state), before, "sweeping moves chips, it doesn't change the total");
        state.seats.forEach(p => assert.equal(p.committed, 0));
        assert.equal(Betting.handTotal(state.seats[2]), 2);
    });
});

describe("Betting all-in run-outs", () => {
    test("with everyone all-in there is nobody left to ask", () => {
        const state = makeTable({ seatCount: 3, seated: [0, 1, 2], stack: 20, dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.allIn(state, 2);
        Betting.allIn(state, 0);
        Betting.allIn(state, 1);

        assert.equal(Betting.canStillBet(state), false);
        assert.equal(Betting.isRunningOut(state), true, "the board just gets dealt out");

        Betting.closeStreet(state);
        assert.equal(state.actingSeatIndex, null, "no phantom action on the flop");
    });

    test("one player with chips against an all-in cannot bet alone", () => {
        const state = makeTable({ seatCount: 3, seated: [0, 1, 2], dealerSeatIndex: 0 });
        state.seats[1].stack = 5;
        Betting.beginHand(state);
        Betting.fold(state, 2);
        Betting.allIn(state, 0);
        Betting.allIn(state, 1);

        assert.equal(Betting.canStillBet(state), false);
        assert.equal(Betting.isHandOver(state), false, "two players are still live for the showdown");
    });

    test("everyone folding to one player ends the hand", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.fold(state, 3);
        Betting.fold(state, 0);
        Betting.fold(state, 1);

        assert.equal(Betting.isHandOver(state), true);
    });
});

describe("Betting money handling", () => {
    test("a player can never put in more than they have", () => {
        const state = makeTable({ seatCount: 3, seated: [0, 1, 2], stack: 30, dealerSeatIndex: 0 });
        Betting.beginHand(state);
        const moved = Betting.putIn(state, 0, 500);
        assert.equal(moved, 30);
        assert.equal(state.seats[0].stack, 0);
    });

    test("raise-to is what a dealer says out loud, not raise-by", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.raiseTo(state, 3, 10);
        assert.equal(state.seats[3].committed, 10, "their street total is 10, not 10 on top");
        assert.equal(state.seats[3].stack, 90);
    });

    test("the minimum raise has to match the last one", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        assert.equal(Betting.minRaiseTo(state), 4, "a big blind of 2 makes the first raise 4");

        Betting.raiseTo(state, 3, 10);
        assert.equal(Betting.minRaiseTo(state), 18, "an 8-chip raise means the next one is to 18");
    });

    test("winnings land back in front of the player", () => {
        const state = makeTable({ seatCount: 3, seated: [0, 1, 2], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.creditWinnings(state, [{ id: state.seats[0].id, amount: 42.5 }]);
        assert.equal(state.seats[0].stack, 142.5, "the button posts nothing three-handed");
    });

    test("fractional blinds don't drift into floating-point dust", () => {
        const state = makeTable({ seatCount: 3, seated: [0, 1, 2], stack: 10, smallBlind: 0.1, bigBlind: 0.2 });
        Betting.beginHand(state);
        Betting.call(state, 0); // button limps
        Betting.call(state, 1); // small blind completes
        Betting.check(state, 2); // big blind is happy
        Betting.closeStreet(state);

        assert.equal(chipsOnTable(state), 30, "0.1 + 0.2 arithmetic didn't lose a chip");
        assert.equal(Betting.potSoFar(state), 0.6);
        state.seats.forEach(p => assert.equal(p.stack, 9.8));
    });
});