Shorten the rulings index to the words a dealer would say

Last change added an index to the rulings sheet and I wrote down what it cost: 342px
at the top of a 390px-wide sheet, so a dealer reading straight through scrolls past
the whole thing first. That was an honest trade at the time. It is also fixable.

The index was labelled with the section headings, which are sentences -- "A short
all-in doesn't reopen the betting" -- so nine of them stacked one per row. A dealer
hunting for that ruling is looking for the words "short all-in", not the sentence.

  Misdeal          Board card early    Out of turn
  Short all-in     Uncalled bet        Oversized chip
  Minimum raise    Odd chip            String bet

  phone       342px -> 143px   9 rows -> 3
  desktop      ~200 -> 70px            -> 2
  landscape          -> 94px           -> 2

The first ruling now starts 309px into the sheet on a phone rather than 440.

Each short label lives on its own section as data-short, next to the heading it
shortens, and the index falls back to the heading when there is not one -- so a ruling
added later still appears, still without anyone having to write it twice. The full
sentence stays as the button's aria-label, so the short label never costs a screen
reader the heading.

Checked at four sizes across touch and pointer contexts: nine labels, nine aria-labels,
every chip 44px on touch, jumping still lands and focuses the right heading, contrast
clean, no console errors. 244 tests still passing.

Also looked at, and left alone: the card picker refuses a card already dealt --
disabled, titled "Already dealt to Ann" -- and every one of its 52 buttons clears 44px.
A messy nine-seat table with 25/50 blinds, two folded players, a busted seat, accented
and hyphenated names, a $125,000 stack and a filled notes field audits clean at every
size but the landscape phone already known from #63.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb

JoshHeaps.Net/Pages/Casino/TexasHoldem.cshtml

@@ -294,7 +294,9 @@
             not during it.
         </p>
 
-        <section class="ruling">
+        <nav id="rulingsIndex" class="rulingsIndex" aria-label="Jump to a ruling"></nav>
+
+        <section class="ruling" data-short="Misdeal">
             <h3>Redeal it — misdeal</h3>
             <ul>
                 <li>The first card goes to the wrong seat.</li>
@@ -304,7 +306,7 @@
             </ul>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Board card early">
             <h3>A board card turned too early</h3>
             <p>
                 If the fourth board card gets turned before the betting round is finished,
@@ -313,7 +315,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Out of turn">
             <h3>Acting out of turn</h3>
             <p>
                 A one-off is usually just backed up if no one has acted behind them.
@@ -321,7 +323,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Short all-in">
             <h3>A short all-in doesn't reopen the betting</h3>
             <p>
                 Somebody shoving in less than a full raise — say $3 more when the last
@@ -336,7 +338,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Uncalled bet">
             <h3>Chips nobody called come back</h3>
             <p>
                 Bet more than anyone was able to call and the excess is returned to you
@@ -346,7 +348,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Oversized chip">
             <h3>One big chip, nothing said</h3>
             <p>
                 The most common argument at a home table. A player facing a bet who
@@ -362,7 +364,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Minimum raise">
             <h3>A raise has to be a full raise</h3>
             <p>
                 At least as much again as the last raise, or the big blind if there
@@ -373,7 +375,7 @@
             </p>
         </section>
 
-        <section class="ruling">
+        <section class="ruling" data-short="Odd chip">
             <h3>The odd chip in a split pot</h3>
             <p>
                 When a chopped pot won't divide evenly, the odd chip goes to the first
@@ -383,6 +385,22 @@
             </p>
         </section>
 
+        <section class="ruling" data-short="String bet">
+            <h3>Betting in one motion — the string bet</h3>
+            <p>
+                A bet is whatever goes in on the first trip to the stack, unless the
+                amount was said out loud first. Reaching back for more chips without
+                having said "raise" is a string bet, and only the first motion stands.
+                Saying the number is always enough on its own: "raise to sixty" binds
+                whatever order the chips arrive in.
+            </p>
+            <p>
+                It's the rule home games invoke most and enforce least, and both are
+                fine — the point is that a player can't watch the table react and then
+                decide how much to bet. Say it, or push it all at once.
+            </p>
+        </section>
+
         <p class="rulingsSource">
             Follows the Tournament Directors Association rules, which most rooms and
             home games take their lead from.

JoshHeaps.Net/wwwroot/css/casino/holdem.css

@@ -1095,6 +1095,51 @@ button,
     line-height: 1.5;
 }
 
+/* One chip per ruling, wrapped across the top of the sheet. Names rather than icons:
+   a dealer scanning this is looking for the words somebody at the table just said. */
+.rulingsIndex {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 0.35rem;
+    margin: 0 0 1rem;
+}
+
+.rulingsIndexBtn {
+    box-sizing: border-box;
+    min-height: 32px;
+    padding: 0.3rem 0.6rem;
+    border-radius: 999px;
+    border: 1px solid #3a3a3a;
+    background: #232323;
+    color: #d8b46a;
+    font-family: inherit;
+    font-size: 0.72rem;
+    line-height: 1.25;
+    text-align: left;
+    cursor: pointer;
+}
+
+@media (hover: hover) {
+    .rulingsIndexBtn:hover {
+        background: #2e2e2e;
+        border-color: #4a4a4a;
+    }
+}
+
+/* A thumb needs the same 44px here as everywhere else. */
+@media (pointer: coarse) {
+    .rulingsIndexBtn {
+        min-height: 44px;
+        font-size: 0.78rem;
+    }
+}
+
+/* The heading the index jumps to takes focus, and a focus ring on a heading that the
+   dealer just asked for reads as noise rather than as help. */
+.ruling h3:focus {
+    outline: none;
+}
+
 .ruling {
     margin-bottom: 1rem;
     padding-left: 0.7rem;
@@ -2603,6 +2648,16 @@ body.hasActionBar #toastHost {
     color: #d6ffe0;
 }
 
+/* The chips to push, under the amount they add up to. Quieter than the payout it
+   belongs to — the dealer reads the name and the money first, then counts. */
+.payoutChips {
+    display: block;
+    margin-top: 0.15rem;
+    font-size: 0.76rem;
+    color: #9fb8a6;
+    font-variant-numeric: tabular-nums;
+}
+
 .potWizardActions {
     display: flex;
     gap: 0.6rem;

JoshHeaps.Net/wwwroot/js/casino/holdem/main.js

@@ -96,6 +96,19 @@ document.addEventListener("DOMContentLoaded", () => {
             });
         },
 
+        // Two players change chairs. Undoable like every other seat action, because a
+        // swap is easy to aim wrong and the seats look alike at a glance.
+        swapSeats: (from, to) => {
+            const movedName = nameOf(from);
+            const intoName = nameOf(to);
+            const wasEmpty = Render.isEmptySeat(state.seats[to]);
+            runUndoable(
+                wasEmpty
+                    ? `${movedName} moved to seat ${to + 1}.`
+                    : `${movedName} and ${intoName} changed seats.`,
+                () => HoldemState.swapSeats(state, from, to));
+        },
+
         makeDealer: index => {
             // Before the deal there's nothing posted, so this is just moving a marker.
             // After it, the blinds have to follow the button or the badges and the
@@ -445,7 +458,50 @@ document.addEventListener("DOMContentLoaded", () => {
     // Escape is Modal's job now, for this sheet and the five others that never had it.
     const rulingsOverlay = document.getElementById("rulingsOverlay");
     const closeRulings = () => { rulingsOverlay.hidden = true; };
-    document.getElementById("openRulingsBtn").addEventListener("click", () => { rulingsOverlay.hidden = false; });
+    // An index across the top of the rulings sheet, one chip per ruling.
+    //
+    // This is opened mid-argument with players waiting, and it was nine rulings of
+    // prose with no way in: reaching the last one meant scrolling 1.6 screens on a
+    // desktop, 2.1 on a phone and 3.5 on a phone held sideways. A dealer looking for
+    // the odd-chip rule had to read past seven others to find it.
+    //
+    // Built from the sections rather than written out beside them, so a ruling added
+    // later turns up in the index without anyone having to remember to add it twice.
+    const buildRulingsIndex = () => {
+        const index = document.getElementById("rulingsIndex");
+        if (!index || index.childElementCount > 0) return;
+        [...rulingsOverlay.querySelectorAll(".ruling")].forEach((section, i) => {
+            const heading = section.querySelector("h3");
+            if (!heading) return;
+            if (!section.id) section.id = `ruling${i + 1}`;
+
+            const jump = document.createElement("button");
+            jump.type = "button";
+            jump.className = "rulingsIndexBtn";
+            // A short label where the ruling gives one. The headings are sentences —
+            // "A short all-in doesn't reopen the betting" — and nine of those stacked
+            // one per row made the index 342px tall on a phone, which is most of the
+            // sheet before the first ruling. "Short all-in" says the same thing to
+            // somebody who is looking for it, and three fit on a line.
+            jump.textContent = section.dataset.short || heading.textContent;
+            // The full heading is still what it announces, so the short label never
+            // costs a screen reader the sentence.
+            if (section.dataset.short) jump.setAttribute("aria-label", heading.textContent);
+            jump.addEventListener("click", () => {
+                section.scrollIntoView({ block: "start", behavior: "smooth" });
+                // The heading is what the dealer is now reading, so that is where the
+                // keyboard and a screen reader should be too.
+                heading.setAttribute("tabindex", "-1");
+                heading.focus({ preventScroll: true });
+            });
+            index.appendChild(jump);
+        });
+    };
+
+    document.getElementById("openRulingsBtn").addEventListener("click", () => {
+        buildRulingsIndex();
+        rulingsOverlay.hidden = false;
+    });
     document.getElementById("closeRulingsBtn").addEventListener("click", closeRulings);
     rulingsOverlay.addEventListener("click", e => {
         if (e.target === rulingsOverlay) closeRulings();

JoshHeaps.Net/wwwroot/js/casino/holdem/money.js

@@ -48,6 +48,58 @@ const Money = {
         return (this.toCents(amount) / 100).toFixed(2);
     },
 
+    // The chips to actually push, for an amount.
+    //
+    // A payout figure is the answer to the arithmetic, not to the dealer's job: they
+    // still have to work out that $132 is two blacks, a green, a red and two whites
+    // while six people watch. The chip legend already knows the denominations.
+    //
+    // Largest first, which is greedy and therefore not optimal for an arbitrary set of
+    // values — but poker chips are not arbitrary. Every real set is canonical (each
+    // denomination divides the next: 1, 5, 25, 100, 500), and greedy is exactly optimal
+    // on those. A dealer who invents a 3-and-7 chip set gets a valid answer that might
+    // use one chip more than it had to.
+    //
+    // Anything the smallest chip can't make comes back as `remainder` rather than being
+    // rounded away: a 50c share in a game whose smallest chip is a dollar is a real
+    // problem for the dealer to solve, not a rounding error to hide.
+    chipBreakdown(amount, legend) {
+        let cents = this.toCents(amount);
+        if (cents <= 0) return { chips: [], remainder: 0 };
+
+        const values = (legend || [])
+            .map(chip => ({ chip, cents: this.toCents(chip.value) }))
+            .filter(entry => entry.cents > 0)
+            .sort((a, b) => b.cents - a.cents);
+
+        const chips = [];
+        values.forEach(entry => {
+            const count = Math.floor(cents / entry.cents);
+            if (count <= 0) return;
+            cents -= count * entry.cents;
+            chips.push({ value: this.fromCents(entry.cents), count, color: entry.chip.color });
+        });
+
+        return { chips, remainder: this.fromCents(cents) };
+    },
+
+    // "2×$50, 1×$25, 2×$1" — the breakdown as a dealer would say it out loud.
+    //
+    // A table with no chip legend gets nothing rather than "$132 no chip covers": it
+    // hasn't told us its denominations, so there is no advice to give and the amount
+    // stands on its own. A legend that exists but can't reach the amount is different,
+    // and does say so.
+    formatChipBreakdown(amount, legend) {
+        const hasDenominations = (legend || []).some(chip => this.toCents(chip.value) > 0);
+        if (!hasDenominations) return "";
+
+        const { chips, remainder } = this.chipBreakdown(amount, legend);
+        if (chips.length === 0 && remainder === 0) return "";
+        const parts = chips.map(chip => `${chip.count}×${this.format(chip.value)}`);
+        if (remainder > 0) parts.push(`${this.format(remainder)} no chip covers`);
+        return parts.join(", ");
+    },
+
     // Should focusing this field select what's already in it?
     //
     // Every amount box in this tool opens pre-filled with a suggestion: the raise pad

JoshHeaps.Net/wwwroot/js/casino/holdem/potWizard.js

@@ -246,10 +246,23 @@ const PotWizard = {
             empty.textContent = "Nobody has money in this pot yet — mark seats \"In hand\" and set contributions first.";
             wrap.appendChild(empty);
         } else {
+            const legend = (this.state && this.state.chipLegend) || [];
             const list = document.createElement("ul");
             for (const [id, amount] of this.totals.entries()) {
                 const li = document.createElement("li");
                 li.textContent = `${this.playerLabelById.get(id)} — ${Money.format(amount)}`;
+
+                // The amount is the answer to the arithmetic; the chips are the answer
+                // to the dealer's job. Only when the legend has been filled in — a
+                // table that never set up chip colours gets the number on its own,
+                // which is what it had before.
+                const chips = Money.formatChipBreakdown(amount, legend);
+                if (chips) {
+                    const note = document.createElement("span");
+                    note.className = "payoutChips";
+                    note.textContent = chips;
+                    li.appendChild(note);
+                }
                 list.appendChild(li);
             }
             wrap.appendChild(list);

JoshHeaps.Net/wwwroot/js/casino/holdem/render.js

@@ -49,11 +49,21 @@ const Render = {
         document.getElementById("defaultStackInput").value = this.state.defaultStack ?? "";
     },
 
+    // Whether this device can actually drag a seat. HTML5 drag events are never
+    // generated from a touch screen, so on a phone the last clause of the hint below
+    // described something impossible — on the device the rest of the sentence was
+    // written for. Touch gets told about the menu route instead, which works.
+    canDragSeats() {
+        return typeof matchMedia !== "function" || matchMedia("(hover: hover)").matches;
+    },
+
     renderTableHint() {
         const hint = document.getElementById("tableHint");
         // Gestures are invisible until someone tells you about them, and this is the
         // only place on the table with room to say so.
-        hint.textContent = "Tap a seat to edit · double-tap to fold · press and hold for quick actions · drag to swap seats.";
+        hint.textContent = this.canDragSeats()
+            ? "Tap a seat to edit · double-tap to fold · press and hold for quick actions · drag to swap seats."
+            : "Tap a seat to edit · double-tap to fold · press and hold for quick actions, including moving a seat.";
     },
 
     renderNotes() {

JoshHeaps.Net/wwwroot/js/casino/holdem/seatMenu.js

@@ -6,10 +6,16 @@ const SeatMenu = {
     hooks: null,
     seatIndex: null,
 
+    mode: null,
+
     open(state, hooks, seatIndex) {
         this.state = state;
         this.hooks = hooks;
         this.seatIndex = seatIndex;
+        // Always the action list, never whatever the sheet was showing when it last
+        // closed — a seat menu that opens on a list of chairs is a menu that lost the
+        // dealer's place.
+        this.mode = null;
         this.render();
         document.getElementById("seatMenuOverlay").hidden = false;
     },
@@ -63,29 +69,81 @@ const SeatMenu = {
             }
         }
 
+        // Changing chairs was drag-and-drop only, and HTML5 drag events are never
+        // generated from a touch screen — so on the device this tool is mostly used on,
+        // the "drag to swap seats" the hint advertised did nothing at all. This is the
+        // same move, by the route a thumb can actually take.
+        if (this.state.seats.length > 1) {
+            actions.push({ label: "Move to…", run: () => this.openMovePicker() });
+        }
+
         actions.push({ label: "Edit seat…", run: () => this.hooks.editSeat(index) });
         return actions;
     },
 
+    // The chairs this player could move to. Every other chair: swapping into an empty
+    // one is how a player moves, and swapping with an occupied one is two players
+    // changing places, which is the other half of the same job.
+    destinationsFor(index) {
+        return this.state.seats
+            .map((player, seat) => ({ player, seat }))
+            .filter(entry => entry.seat !== index);
+    },
+
+    openMovePicker() {
+        this.mode = "move";
+        this.render();
+    },
+
     render() {
         const player = this.state.seats[this.seatIndex];
-        document.getElementById("seatMenuTitle").textContent = HoldemState.displayName(player, this.seatIndex);
+        const title = document.getElementById("seatMenuTitle");
+        const subtitle = document.getElementById("seatMenuSubtitle");
+        const list = document.getElementById("seatMenuActions");
+        list.innerHTML = "";
+
+        if (this.mode === "move") {
+            title.textContent = `Move ${HoldemState.displayName(player, this.seatIndex)} to…`;
+            subtitle.textContent = "Their chips, cards and bet go with them. The button and the blinds stay on the chair.";
+            this.destinationsFor(this.seatIndex).forEach(({ player: other, seat }) => {
+                const btn = document.createElement("button");
+                btn.type = "button";
+                btn.className = "seatMenuBtn";
+                // displayName falls back to "Seat 5" for a chair with nobody in it,
+                // which reads as "Seat 5 — Seat 5". An empty chair says it's empty.
+                const named = (other.name || "").trim();
+                btn.textContent = named ? `Seat ${seat + 1} — ${named}` : `Seat ${seat + 1} — empty`;
+                btn.addEventListener("click", () => {
+                    const from = this.seatIndex;
+                    this.close();
+                    this.hooks.swapSeats(from, seat);
+                });
+                list.appendChild(btn);
+            });
+            return;
+        }
+
+        title.textContent = HoldemState.displayName(player, this.seatIndex);
 
         const stack = Betting.stackOf(this.state, player);
         const owed = Betting.toCall(this.state, player);
         const bits = [];
         if (stack > 0) bits.push(`${Money.format(stack)} behind`);
         if (owed > 0) bits.push(`${Money.format(owed)} to call`);
-        document.getElementById("seatMenuSubtitle").textContent = bits.join(" · ");
+        subtitle.textContent = bits.join(" · ");
 
-        const list = document.getElementById("seatMenuActions");
-        list.innerHTML = "";
         this.actionsFor(player, this.seatIndex).forEach(action => {
             const btn = document.createElement("button");
             btn.type = "button";
             btn.className = `seatMenuBtn ${action.className || ""}`;
             btn.textContent = action.label;
             btn.addEventListener("click", () => {
+                // "Move to…" stays on the sheet and swaps it for the seat list; every
+                // other action is the end of the interaction.
+                if (action.label === "Move to…") {
+                    action.run();
+                    return;
+                }
                 this.close();
                 action.run();
             });

JoshHeaps.Net/wwwroot/js/casino/holdem/state.js

@@ -467,6 +467,21 @@ const HoldemState = {
             .sort((a, b) => b.net - a.net);
     },
 
+    // Two players change chairs.
+    //
+    // The whole seat moves — name, stack, cards, what they have in the pot — because
+    // that is what changing chairs is. What stays behind is everything that belongs to
+    // the *position*: the button, the blinds and the acting index all name a chair, and
+    // a player who moves into the big blind's chair is the big blind. That is the same
+    // answer a card room gives.
+    swapSeats(state, a, b) {
+        const seats = state.seats || [];
+        if (a === b) return false;
+        if (!seats[a] || !seats[b]) return false;
+        [seats[a], seats[b]] = [seats[b], seats[a]];
+        return true;
+    },
+
     // The one check a banker actually needs, and the one nothing here did.
     //
     // Every chip on the table is a promise to pay cash for it later. If the chips in

tests/holdem/chipBreakdown.test.js

@@ -0,0 +1,82 @@
+// The chips to actually push, for an amount.
+const test = require("node:test");
+const assert = require("node:assert");
+const { Money } = require("./load");
+
+// A standard house set.
+const LEGEND = [
+    { value: 1, color: "#fff" },
+    { value: 5, color: "#c0392b" },
+    { value: 25, color: "#27ae60" },
+    { value: 100, color: "#2c3e50" },
+    { value: 500, color: "#8e44ad" },
+];
+
+const say = (amount, legend = LEGEND) => Money.formatChipBreakdown(amount, legend);
+
+test("a payout comes back as chips, largest first", () => {
+    assert.equal(say(132), "1×$100, 1×$25, 1×$5, 2×$1");
+});
+
+test("it uses the fewest chips on a normal set", () => {
+    const { chips } = Money.chipBreakdown(500, LEGEND);
+    assert.deepEqual(chips.map(c => `${c.count}×${c.value}`), ["1×500"]);
+});
+
+test("a denomination that doesn't fit is skipped rather than listed as none", () => {
+    assert.equal(say(7), "1×$5, 2×$1");
+});
+
+test("nothing to pay is nothing to say", () => {
+    assert.equal(say(0), "");
+    assert.equal(say(-5), "");
+});
+
+test("no legend means no advice, not a wrong answer", () => {
+    // A table that never set chip colours up gets the amount on its own.
+    assert.equal(say(132, []), "");
+    assert.equal(say(132, null), "");
+});
+
+test("a legend with no values in it yet is the same as none", () => {
+    assert.equal(say(132, [{ value: "", color: "#fff" }, { value: 0, color: "#000" }]), "");
+});
+
+test("what the smallest chip can't make is reported, not rounded away", () => {
+    // 50c in a game whose smallest chip is a dollar is the dealer's problem to solve,
+    // and they can only solve it if they're told.
+    const { chips, remainder } = Money.chipBreakdown(10.5, LEGEND);
+    assert.deepEqual(chips.map(c => `${c.count}×${c.value}`), ["2×5"]);
+    assert.equal(remainder, 0.5);
+    assert.equal(say(10.5), "2×$5, $0.50 no chip covers");
+});
+
+test("cent chips make cent amounts exactly", () => {
+    const cents = [{ value: 0.25 }, { value: 0.05 }, { value: 0.01 }];
+    assert.equal(say(0.41, cents), "1×$0.25, 3×$0.05, 1×$0.01");
+    assert.equal(Money.chipBreakdown(0.41, cents).remainder, 0);
+});
+
+test("the chips add up to the amount", () => {
+    for (const amount of [1, 7, 33, 132, 499, 500, 1234, 9999]) {
+        const { chips, remainder } = Money.chipBreakdown(amount, LEGEND);
+        const total = chips.reduce((sum, c) => sum + c.count * c.value, 0) + remainder;
+        assert.equal(Money.round(total), amount, `${amount} should be accounted for`);
+    }
+});
+
+test("a legend in any order still pays largest first", () => {
+    const jumbled = [{ value: 25 }, { value: 1 }, { value: 500 }, { value: 5 }, { value: 100 }];
+    assert.equal(say(631, jumbled), "1×$500, 1×$100, 1×$25, 1×$5, 1×$1");
+});
+
+test("the colour comes along, so the felt can say it in chips", () => {
+    const { chips } = Money.chipBreakdown(25, LEGEND);
+    assert.equal(chips[0].color, "#27ae60");
+});
+
+test("a legend that exists but can't reach the amount does say so", () => {
+    // Different from having no legend at all: this table has told us its chips, and
+    // the answer is that they don't go that low.
+    assert.equal(say(3, [{ value: 5 }, { value: 25 }]), "$3 no chip covers");
+});

tests/holdem/swapSeats.test.js

@@ -0,0 +1,95 @@
+// Two players changing chairs.
+const test = require("node:test");
+const assert = require("node:assert");
+const { Betting, HoldemState, makeTable, chipsOnTable } = require("./load");
+
+test("the whole seat moves", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100 });
+    state.seats[0].name = "Ann";
+    state.seats[0].cards = ["AS", "KD"];
+    state.seats[0].stack = 175;
+    state.seats[4].name = "";
+
+    HoldemState.swapSeats(state, 0, 4);
+
+    assert.equal(state.seats[4].name, "Ann");
+    assert.deepEqual(state.seats[4].cards, ["AS", "KD"]);
+    assert.equal(state.seats[4].stack, 175);
+    assert.equal(state.seats[0].name, "");
+});
+
+test("what they have in the pot goes with them", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100 });
+    Betting.beginHand(state);
+    const posted = state.seats.map(p => p.committed);
+    const before = chipsOnTable(state);
+
+    HoldemState.swapSeats(state, 1, 4);
+
+    assert.equal(state.seats[4].committed, posted[1]);
+    assert.equal(state.seats[1].committed, posted[4]);
+    assert.equal(chipsOnTable(state), before, "a swap never creates or destroys a chip");
+});
+
+test("the button stays on the chair, not on the player", () => {
+    // A card room moves the button around the table, not around the people. Somebody
+    // who sits down in the big blind's chair is the big blind.
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2], stack: 100, dealerSeatIndex: 0 });
+    state.seats[0].name = "Ann";
+
+    HoldemState.swapSeats(state, 0, 2);
+
+    assert.equal(state.dealerSeatIndex, 0);
+    assert.notEqual(state.seats[0].name, "Ann");
+});
+
+test("the blinds follow the chairs too", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], stack: 100, dealerSeatIndex: 0 });
+    Betting.beginHand(state);
+    const before = HoldemState.getBlindSeats(state);
+
+    HoldemState.swapSeats(state, before.sbIndex, before.bbIndex);
+    const after = HoldemState.getBlindSeats(state);
+
+    assert.equal(after.sbIndex, before.sbIndex);
+    assert.equal(after.bbIndex, before.bbIndex);
+});
+
+test("swapping a seat with itself does nothing and says so", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    const before = JSON.stringify(state);
+
+    assert.equal(HoldemState.swapSeats(state, 1, 1), false);
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("a chair that isn't there is refused rather than swallowed", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    const before = JSON.stringify(state);
+
+    assert.equal(HoldemState.swapSeats(state, 0, 99), false);
+    assert.equal(HoldemState.swapSeats(state, -1, 0), false);
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("swapping twice puts everything back", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], stack: 100 });
+    Betting.beginHand(state);
+    const before = JSON.stringify(state);
+
+    HoldemState.swapSeats(state, 1, 3);
+    HoldemState.swapSeats(state, 1, 3);
+
+    assert.equal(JSON.stringify(state), before);
+});
+
+test("moving into an empty chair leaves an empty chair behind", () => {
+    const state = makeTable({ seatCount: 6, seated: [0, 1], stack: 100 });
+    state.seats[1].name = "Ben";
+
+    HoldemState.swapSeats(state, 1, 5);
+
+    assert.equal(state.seats[5].name, "Ben");
+    assert.equal(state.seats[5].inHand, true);
+    assert.equal(state.seats[1].inHand, false);
+});

tests/holdem/uiAudit.js

@@ -522,8 +522,15 @@ const LayoutAudit = {
         const chips = [...document.querySelectorAll(".dealerChip")];
         const shown = chips.filter(chip => {
             const style = getComputedStyle(chip);
-            return style.display !== "none" && style.visibility !== "hidden" &&
+            if (style.display === "none" || style.visibility === "hidden") return false;
-                parseFloat(style.opacity) > 0.05;
+            if (parseFloat(style.opacity) <= 0.05) return false;
+            // A hovered seat deliberately fades its empty slot in — that's the "put the
+            // button here" preview, and it is on screen because a pointer is sitting on
+            // that seat. Counting it reports two buttons whenever the mouse happens to
+            // rest on the table, which is most of the time a mouse exists.
+            const seat = chip.closest(".seat");
+            if (seat && seat.matches(":hover") && !chip.classList.contains("active")) return false;
+            return true;
         });
         const offenders = [];