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

// When does a bet reopen the action? The most misread rule in poker, and the one a
// home game argues about longest: a player shoving in less than a full raise does not
// give everybody behind them another go.
//
// TDA Rule 44 — an all-in wager of less than a full raise does not reopen the betting
// to a player who has already acted and is not facing a full raise.
const { test, describe } = require("node:test");
const assert = require("node:assert/strict");
const { Betting, makeTable, chipsOnTable } = require("./load");

const actedFlags = state => state.seats
    .map((p, i) => ({ seat: i, acted: p.hasActed, live: p.inHand && !p.folded }))
    .filter(s => s.live);

describe("a short all-in does not reopen the betting", () => {
    // Blinds 1/2. Seat 4 raises to 10 (a full raise of 8). Seat 1 calls.
    // Seat 2 is all-in for 13 — three more, where a full raise needs eight.
    const shortAllInTable = () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        state.seats[1].stack = 13;
        Betting.beginHand(state);
        Betting.raiseTo(state, 3, 10);
        Betting.call(state, 0);
        return state;
    };

    test("players who already acted are not asked to act again", () => {
        const state = shortAllInTable();
        assert.equal(state.seats[0].hasActed, true, "seat 1 has called");
        assert.equal(state.seats[3].hasActed, true, "seat 4 has raised");

        Betting.allIn(state, 1);

        assert.equal(state.seats[0].hasActed, true, "seat 1 must not be reopened");
        assert.equal(state.seats[3].hasActed, true, "seat 4 must not be reopened");
    });

    test("but they do still owe the difference", () => {
        const state = shortAllInTable();
        Betting.allIn(state, 1);

        assert.equal(Betting.toCall(state, state.seats[0]), 3, "seat 1 owes the extra 3");
        assert.equal(Betting.isStreetComplete(state), false, "so the street isn't over");
    });

    test("a player who had not acted yet keeps full rights", () => {
        const state = shortAllInTable();
        assert.equal(state.seats[2].hasActed, false, "seat 3 hasn't acted");
        Betting.allIn(state, 1);
        assert.equal(state.seats[2].hasActed, false, "and still hasn't — they may still raise");
    });

    test("the minimum raise is not shrunk by the short all-in", () => {
        const state = shortAllInTable();
        assert.equal(state.lastRaiseSize, 8);

        Betting.allIn(state, 1);

        assert.equal(state.lastRaiseSize, 8, "still the last *full* raise");
        assert.equal(Betting.minRaiseTo(state), 21, "13 to call plus a full raise of 8");
    });

    test("calling the short all-in ends the street", () => {
        const state = shortAllInTable();
        Betting.allIn(state, 1);
        Betting.call(state, 2);   // seat 3, who had full rights, just calls
        Betting.call(state, 3);
        Betting.call(state, 0);
        assert.equal(Betting.isStreetComplete(state), true);
    });

    test("no chips are created or lost by any of it", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        state.seats[1].stack = 13;
        const start = chipsOnTable(state);
        Betting.beginHand(state);
        Betting.raiseTo(state, 3, 10);
        Betting.call(state, 0);
        Betting.allIn(state, 1);
        Betting.call(state, 2);
        Betting.call(state, 3);
        Betting.call(state, 0);
        assert.equal(chipsOnTable(state), start);
    });
});

describe("a full raise still reopens the betting", () => {
    test("an all-in that is a full raise or more reopens everyone", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        state.seats[1].stack = 40;
        Betting.beginHand(state);
        Betting.raiseTo(state, 3, 10);
        Betting.call(state, 0);

        Betting.allIn(state, 1);   // to 40: an increase of 30, well over the 8 needed

        assert.equal(state.seats[0].hasActed, false, "seat 1 gets another go");
        assert.equal(state.seats[3].hasActed, false, "and so does seat 4");
        assert.equal(state.lastRaiseSize, 30);
        assert.equal(Betting.minRaiseTo(state), 70);
    });

    test("an ordinary raise reopens everyone", () => {
        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);
        assert.equal(state.seats[0].hasActed, false);
    });

    test("a raise exactly the size of the last one counts as full", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.raiseTo(state, 3, 10);      // raise of 8
        Betting.call(state, 0);

        Betting.raiseTo(state, 1, 18);      // exactly 8 more — a legal minimum raise

        assert.equal(state.seats[0].hasActed, false, "a minimum raise still reopens");
        assert.equal(state.lastRaiseSize, 8);
    });

    test("the first raise of a street is measured against the big blind", () => {
        const state = makeTable({ seatCount: 4, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
        Betting.beginHand(state);
        Betting.call(state, 3);
        Betting.call(state, 0);
        Betting.call(state, 1);
        Betting.check(state, 2);
        Betting.closeStreet(state);         // to the flop, no bet yet

        const first = Betting.nextToAct(state, state.dealerSeatIndex);
        Betting.raiseTo(state, first, 2);   // a bet of exactly one big blind

        const others = state.seats.filter((p, i) => p.inHand && !p.folded && i !== first);
        assert.ok(others.every(p => p.hasActed === false), "a full-sized opening bet reopens everyone");
    });
});