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

// Dealing and betting are two decisions, and fusing them meant the table guessed.
//
// The moment between hands is when people sit down, stand up and argue about whose
// turn it is. With blinds posted the instant the previous hand ended, the blind
// badges recomputed off `inHand` while the committed chips stayed frozen — so seating
// somebody produced a big blind who had posted nothing.
const { test, describe } = require("node:test");
const assert = require("node:assert/strict");
const { Betting, HoldemState, makeTable, chipsOnTable } = require("./load");

const postedBy = state => state.seats
    .map((p, i) => (Betting.committed(p) > 0 ? i : null))
    .filter(i => i !== null);

describe("the table waits to be dealt", () => {
    test("finishing a hand leaves the next one un-dealt", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        Betting.beginHand(state);
        assert.equal(state.bettingOpen, true);

        HoldemState.startNextHand(state);

        assert.equal(state.bettingOpen, false, "the next hand hasn't been dealt");
        assert.equal(state.actingSeatIndex, null, "nobody is on the clock");
        assert.deepEqual(postedBy(state), [], "and no blind has been committed");
    });

    test("no money moves until the dealer deals", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        const start = chipsOnTable(state);
        HoldemState.startNextHand(state);

        assert.equal(chipsOnTable(state), start);
        assert.equal(HoldemState.totalPot(state), 0);

        Betting.beginHand(state);
        assert.equal(state.bettingOpen, true);
        assert.equal(postedBy(state).length, 2, "now the blinds are in");
        assert.equal(chipsOnTable(state), start, "and nothing was created doing it");
    });
});

describe("setting the table costs nothing", () => {
    test("seating a player before the deal changes who posts", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        HoldemState.startNextHand(state);

        const before = Betting.blindPreview(state);
        state.seats[3].inHand = true;
        state.seats[3].stack = 100;
        const after = Betting.blindPreview(state);

        assert.notDeepEqual(
            [before.sbIndex, before.bbIndex],
            [after.sbIndex, after.bbIndex],
            "the preview follows the new table"
        );
        assert.deepEqual(postedBy(state), [], "and still nothing is committed");

        Betting.beginHand(state);
        assert.deepEqual(postedBy(state).sort(), [after.sbIndex, after.bbIndex].sort(),
            "the money lands where the preview said it would");
    });

    test("removing a player before the deal can't strand their blind", () => {
        // The old failure: take out the big blind after the hand had begun and their
        // chips stayed in the pot while the badge moved to somebody who'd posted
        // nothing. Before the deal there is nothing to strand.
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        HoldemState.startNextHand(state);

        const doomed = Betting.blindPreview(state).bbIndex;
        state.seats[doomed].inHand = false;

        assert.deepEqual(postedBy(state), [], "nobody has posted, so nothing is stranded");

        Betting.beginHand(state);
        const posted = postedBy(state);
        assert.ok(!posted.includes(doomed), "the player who left posts nothing");
        posted.forEach(i => assert.ok(state.seats[i].inHand, "only players in the hand post"));
    });

    test("moving the button before the deal just moves it", () => {
        const state = makeTable({ seatCount: 8, seated: [0, 2, 4, 6], dealerSeatIndex: 0 });
        const start = chipsOnTable(state);
        HoldemState.startNextHand(state);

        [2, 4, 6, 0].forEach(seat => {
            state.dealerSeatIndex = seat;
            assert.deepEqual(postedBy(state), [], `passing the button to seat ${seat + 1} posted something`);
            assert.equal(chipsOnTable(state), start);
        });

        Betting.beginHand(state);
        assert.equal(chipsOnTable(state), start, "dealing moves chips between stacks, not into thin air");
    });

    test("what the preview promises is what gets posted", () => {
        const state = makeTable({ seatCount: 9, seated: [1, 3, 6, 8], dealerSeatIndex: 1 });
        HoldemState.startNextHand(state);

        const preview = Betting.blindPreview(state);
        Betting.beginHand(state);

        assert.equal(Betting.committed(state.seats[preview.sbIndex]), preview.smallBlind);
        assert.equal(Betting.committed(state.seats[preview.bbIndex]), preview.bigBlind);
    });

    test("there's nothing to preview without two players", () => {
        const alone = makeTable({ seatCount: 6, seated: [2] });
        HoldemState.startNextHand(alone);
        assert.equal(Betting.blindPreview(alone), null);

        const empty = makeTable({ seatCount: 6, seated: [] });
        HoldemState.startNextHand(empty);
        assert.equal(Betting.blindPreview(empty), null);
    });

    test("a hand-picked blind shows up in the preview", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], dealerSeatIndex: 0 });
        HoldemState.startNextHand(state);
        state.blindOverride = { sbIndex: 3, bbIndex: 0 };

        const preview = Betting.blindPreview(state);
        assert.equal(preview.manual, true);
        assert.equal(preview.sbIndex, 3);
        assert.equal(preview.bbIndex, 0);
    });
});

describe("a table saved mid-hand comes back mid-hand", () => {
    const loadWith = saved => {
        const original = globalThis.localStorage;
        globalThis.localStorage = { getItem: () => JSON.stringify(saved), setItem: () => {}, removeItem: () => {} };
        const state = HoldemState.load();
        globalThis.localStorage = original;
        return state;
    };

    test("chips already committed mean the betting was open", () => {
        const state = loadWith({
            seats: [{ id: "a", name: "Ann", inHand: true, committed: 2 }, { id: "b", name: "Ben", inHand: true, committed: 0 }],
            handNumber: 3,
        });
        assert.equal(state.bettingOpen, true, "otherwise it would offer to deal over a live hand");
    });

    test("somebody on the clock means the betting was open", () => {
        const state = loadWith({
            seats: [{ id: "a", inHand: true }, { id: "b", inHand: true }],
            actingSeatIndex: 1, handNumber: 2,
        });
        assert.equal(state.bettingOpen, true);
    });

    test("a quiet table comes back waiting to be dealt", () => {
        const state = loadWith({
            seats: [{ id: "a", inHand: true }, { id: "b", inHand: true }],
            actingSeatIndex: null, handNumber: 5,
        });
        assert.equal(state.bettingOpen, false);
    });
});

describe("the preview tells the truth about the button", () => {
    test("a button parked on an empty chair is answered for where it will be", () => {
        // The preview used to read the button where it sat, while dealing relocated it
        // first — so it promised one pair of blinds and produced another.
        const state = makeTable({ seatCount: 6, seated: [1, 2, 3], dealerSeatIndex: 0 });
        state.bettingOpen = false;
        assert.equal(state.seats[0].inHand, false, "the button is on an empty chair");

        const preview = Betting.blindPreview(state);
        assert.equal(preview.buttonMoves, true, "and the preview knows it will move");

        Betting.beginHand(state);

        assert.equal(Betting.committed(state.seats[preview.sbIndex]), preview.smallBlind);
        assert.equal(Betting.committed(state.seats[preview.bbIndex]), preview.bigBlind);
        assert.equal(state.dealerSeatIndex, preview.buttonIndex, "and it moved where it said");
    });

    test("asking where the button will be doesn't move it", () => {
        const state = makeTable({ seatCount: 6, seated: [1, 2, 3], dealerSeatIndex: 0 });
        state.bettingOpen = false;

        Betting.blindPreview(state);
        Betting.blindPreview(state);

        assert.equal(state.dealerSeatIndex, 0, "the preview is a question, not an action");
    });

    test("a button already on a player is left alone", () => {
        const state = makeTable({ seatCount: 6, seated: [0, 1, 2], dealerSeatIndex: 0 });
        state.bettingOpen = false;
        const preview = Betting.blindPreview(state);
        assert.equal(preview.buttonMoves, false);
        assert.equal(preview.buttonIndex, 0);
    });

    test("buttonSeatForDeal copes with a table nobody is sitting at", () => {
        const state = makeTable({ seatCount: 6, seated: [] });
        assert.equal(HoldemState.buttonSeatForDeal(state), state.dealerSeatIndex);
    });
});