Make the dealer tool work with no signal, and stop it shouting

Three findings this round, all measured on the running page.

**1. The tool needed the internet to exist.**

The night already survived anything — it lives in localStorage — but the page
did not. Reload in somebody's back room with one bar of signal and a dealer
holding a phone in one hand and a deck in the other got a browser error page
with nine players waiting. Verified: with no worker, an offline reload is
net::ERR_INTERNET_DISCONNECTED.

There is now a service worker (wwwroot/casino/sw.js) and a manifest, so the
tool installs to a home screen and runs with the network switched off. Measured
end to end: 19 assets cached from one ordinary visit, then with the context
offline the page loads, draws six seats, applies its CSS, and plays a whole
hand — blinds posted, four calls, $800 still on the table.

Three decisions worth writing down:

  * The precache list is read off the document rather than kept in the worker.
    Every stylesheet and script is already in the DOM; a hand-written file list
    stays right until somebody adds a script tag, and then the tool is quietly
    offline-broken until a dealer finds out at a table.
  * No skipWaiting. A new worker taking over a live page can hand it assets
    from a different release than the ones it started with, and this page loads
    seventeen scripts that expect to agree with each other.
  * Stale-while-revalidate for assets, not cache-first — see finding 3.

Scope is /casino/ rather than /casino/texasholdem/, because a scope has to be a
prefix of the page it controls and "/casino/texasholdem" does not start with
"/casino/texasholdem/". Anything in scope the worker wasn't told about goes
straight to the network.

Program.cs needed .webmanifest added to the MIME map: an unknown extension is
not served with the wrong type, it is not served at all, and a 404 manifest is
exactly the silent failure that stops a browser ever offering "Add to Home
Screen".

**2. A screen reader read out the whole action bar after every tap.**

The bar carried aria-live on the element whose entire contents render() rebuilds
each action. Measured, after one tap:

  "PRE-FLOP Pot $15 9 players Bob · $250 behind 0:00 ↶ dealing the hand U
   Fold Call $10 Raise"

Nothing in it is wrong; it is unusable at the speed a hand is dealt, and it is
the documented anti-pattern — a live region has to be a stable element whose
text changes, not a container that gets replaced. There is now a small
role="status" element that exists from page load and says one sentence:
"Dee to act, $10 to call. Pot $15." Guarded on the sentence rather than on the
state, because render() runs for many reasons that don't change whose turn it
is, and a live region handed the same words twice reads them twice.

**3. Every tap rebuilt ninety DOM nodes.**

renderSeats did `innerHTML = ""` and then cloned a template, attached three sets
of listeners and set a dozen attributes per chair — on every render, and
renderAll runs after every action. Profiled on a nine-handed table:

  renderSeats   7.3ms -> 4.0ms
  renderAll    12.4ms -> 9.5ms

The pucks are built once and updated in place, which is what the rest of that
function was already doing to their contents. A seat's node belongs to its index
for as long as the table is that size, so the listeners still close over the
index; only a change in the number of chairs rebuilds the row. Verified that
listeners don't stack: one click after six renders fires the hook exactly once,
and resizing 9 -> 4 -> 10 renumbers correctly.

Found along the way and deliberately left alone: ViewData["cssVersion"] renders
empty on every page of the site, so the ?v= cache-busting has never worked. It
is inert — Program.cs sends Cache-Control: no-store on all static files — and
the service worker was the only reason to care, which is why it uses
stale-while-revalidate instead. Noted in TexasHoldem.cshtml.

608 tests, 0 failures, including a new announcing.test.js. 52 layout audits
across 13 viewports x 4 table sizes: 0 failures, and the action bar still
doesn't change height mid-hand. Gestures re-verified after the seat refactor:
double-tap fold, long-press menu, give-the-button, and the active dealer chip.

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

JoshHeaps.Net/Pages/Casino/TexasHoldem.cshtml

@@ -580,7 +580,17 @@
     </div>
 </div>
 
-<div id="actionBar" aria-live="polite" hidden></div>
+@* No aria-live here any more. This element's entire contents are rebuilt on every
+   action, so a live region on it announced the whole bar every time — measured, after
+   one tap: "PRE-FLOP Pot $15 9 players Bob · $250 behind 0:00 ↶ dealing the hand U
+   Fold Call $10 Raise". That is what a screen reader read out after every single fold.
+   A live region has to be a stable element whose *text* changes; the one below is. *@
+<div id="actionBar" hidden></div>
+
+@* Whose turn it is, in a sentence. Empty in the markup and only ever written to, so
+   assistive tech is already watching it when the first update lands — a live region
+   created at the moment it has something to say is one the screen reader misses. *@
+<div id="actionAnnouncer" role="status" aria-live="polite" class="visuallyHidden"></div>
 
 <div id="toastHost" aria-live="polite"></div>
 
@@ -607,8 +617,31 @@
 
 @section Styles {
     <link href="/css/casino/holdem.css?v=@ViewData["cssVersion"]" rel="stylesheet" type="text/css" />
+
+    @* Installable, and works with no signal — see the service worker registration at the
+       foot of main.js. A dealer running a night in somebody's back room is on the worst
+       network there is, and the tool being a *website* was the last thing that could
+       take it away from them mid-game. *@
+    <link rel="manifest" href="/casino/holdem.webmanifest" />
+    @* iOS reads none of the manifest's icons and only this. *@
+    <link rel="apple-touch-icon" href="/images/casino/holdem-apple-touch.png" />
+    <meta name="apple-mobile-web-app-capable" content="yes" />
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
+    <meta name="apple-mobile-web-app-title" content="Hold'em" />
+    @* Paints the phone's chrome the same near-black as the felt's ground, so an
+       installed copy doesn't sit under a white status bar. *@
+    <meta name="theme-color" content="#141414" />
 }
 
+@* A note for whoever reads the ?v= below and assumes it works: it doesn't. ViewData
+   ["cssVersion"] is assigned in _Layout's own code block, which runs after these
+   sections are handed their values, so every one of these renders as a bare "?v=" —
+   on this page and on Chess, Particles and Memory Lane too. It is inert rather than
+   broken: Program.cs sends `Cache-Control: no-store` on every static file, so nothing
+   is being browser-cached for a version string to bust in the first place.
+   Left alone deliberately. Fixing it is a one-line change to a file every page on the
+   site shares, and the service worker was the reason to care — that now uses stale-
+   while-revalidate, which needs no version to stay current. *@
 @section Scripts {
     <script src="~/js/casino/holdem/money.js?v=@ViewData["cssVersion"]"></script>
     <script src="~/js/casino/holdem/feedback.js?v=@ViewData["cssVersion"]"></script>

JoshHeaps.Net/Program.cs

@@ -1,6 +1,7 @@
 using JoshHeaps.Net.Hubs;
 using JoshHeaps.Net.Services.Implementations;
 using JoshHeaps.Net.Services.Interfaces;
+using Microsoft.AspNetCore.StaticFiles;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -52,8 +53,16 @@ if (!app.Environment.IsDevelopment())
 
 app.UseHttpsRedirection();
 
+// .webmanifest isn't in the default MIME map, and an unknown extension isn't served
+// with the wrong type — it isn't served at all. Without this the Hold'em tool's
+// manifest 404s, and a 404 manifest is exactly the silent failure that stops a browser
+// ever offering "Add to Home Screen": nothing is logged and no prompt appears.
+var contentTypes = new FileExtensionContentTypeProvider();
+contentTypes.Mappings[".webmanifest"] = "application/manifest+json";
+
 app.UseStaticFiles(new StaticFileOptions
 {
+    ContentTypeProvider = contentTypes,
     OnPrepareResponse = ctx =>
     {
         ctx.Context.Response.Headers.Append("Cache-Control", "no-cache, no-store, must-revalidate");

JoshHeaps.Net/wwwroot/casino/holdem.webmanifest

@@ -0,0 +1,32 @@
+{
+  "name": "Texas Hold'em Dealer",
+  "short_name": "Hold'em",
+  "description": "Seat your players, track the action, split the pot. Works with no signal.",
+  "start_url": "/casino/texasholdem",
+  "scope": "/casino/",
+  "display": "standalone",
+  "orientation": "any",
+  "background_color": "#141414",
+  "theme_color": "#141414",
+  "categories": ["utilities"],
+  "icons": [
+    {
+      "src": "/images/casino/holdem-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/images/casino/holdem-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/images/casino/holdem-maskable-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "maskable"
+    }
+  ]
+}

JoshHeaps.Net/wwwroot/casino/sw.js

@@ -0,0 +1,125 @@
+// Keeps the dealer tool working when the network doesn't.
+//
+// A home game is the worst network in the world: somebody's back room, one bar of
+// signal, a router two floors away. The tool already keeps the whole night in
+// localStorage, so the *table* survives anything — but the page didn't. Reload with no
+// signal, or open it fresh when the wifi has dropped, and a dealer holding a phone in
+// one hand and a deck in the other got a browser error page with nine players waiting.
+//
+// This is the one thing standing between "a website about poker" and "a tool you can
+// rely on at a table", so it is worth the moving part.
+//
+// Scope is /casino/ rather than /casino/texasholdem/, because a scope has to be a
+// prefix of the page it controls and "/casino/texasholdem" does not start with
+// "/casino/texasholdem/". Anything in that scope this worker has not been told about
+// goes straight to the network, so the other casino pages behave exactly as they did.
+
+// Bumped whenever the shape of what is cached changes. The asset *version* rides in
+// the URLs themselves (?v=1.0.8 from _Layout), so a normal release makes new keys
+// without touching this.
+const CACHE = "holdem-shell-v1";
+
+// What this worker will keep. Anything else in scope — a form post, an API call, a
+// page it was never told about — goes straight to the network and behaves exactly as
+// it did before the worker existed.
+const CACHEABLE = new Set(["script", "style", "image", "font", "manifest"]);
+
+// The page hands over the exact list of URLs it was built from — see registerWorker()
+// in main.js. Deriving it from the document instead of keeping a list here is the
+// whole trick: a hand-written manifest of files drifts from the markup the first time
+// somebody adds a script tag, and the failure mode is a tool that is offline-capable
+// right up until the release that quietly broke it.
+async function precache(urls) {
+    const cache = await caches.open(CACHE);
+    // Individually rather than cache.addAll, which rejects the whole batch if any one
+    // URL 404s — one stale entry in the list would leave the dealer with nothing.
+    await Promise.all(urls.map(async url => {
+        try {
+            const res = await fetch(url, { cache: "reload" });
+            if (res.ok) await cache.put(url, res);
+        } catch {
+            // Offline while installing. The runtime handler below picks these up on
+            // the next online visit.
+        }
+    }));
+}
+
+// No install handler, and deliberately no skipWaiting(). A new worker taking over a
+// live page can hand it assets from a different release than the ones it started with,
+// and this page loads seventeen separate scripts that expect to agree with each other.
+// Waiting costs a dealer nothing — the update lands the next time they open the tool —
+// and it cannot leave them with a half-swapped app in the middle of a hand.
+
+self.addEventListener("activate", event => {
+    event.waitUntil((async () => {
+        const keys = await caches.keys();
+        await Promise.all(keys
+            .filter(key => key.startsWith("holdem-shell-") && key !== CACHE)
+            .map(key => caches.delete(key)));
+        await self.clients.claim();
+    })());
+});
+
+self.addEventListener("message", event => {
+    if (event.data && event.data.type === "precache" && Array.isArray(event.data.urls)) {
+        event.waitUntil(precache(event.data.urls));
+    }
+});
+
+// Only GETs, and only same-origin. A cross-origin request has opaque responses that
+// can't be inspected, and caching one would mean serving a failure forever.
+function handles(request) {
+    if (request.method !== "GET") return false;
+    const url = new URL(request.url);
+    return url.origin === self.location.origin;
+}
+
+self.addEventListener("fetch", event => {
+    const { request } = event;
+    if (!handles(request)) return;
+
+    // The page itself: network first, so an online dealer always gets the current
+    // build, and the cached copy is there the moment they aren't.
+    if (request.mode === "navigate") {
+        event.respondWith((async () => {
+            try {
+                const fresh = await fetch(request);
+                if (fresh.ok) (await caches.open(CACHE)).put(request, fresh.clone());
+                return fresh;
+            } catch {
+                const cached = await caches.match(request, { ignoreSearch: true });
+                if (cached) return cached;
+                throw new Error("offline and this page was never cached");
+            }
+        })());
+        return;
+    }
+
+    // Assets: stale while revalidate. The cached copy answers immediately — which is
+    // the whole point, a dealer opening this between hands should not wait for a
+    // network — and a fresh copy is fetched in the background for next time.
+    //
+    // Cache-first would be the obvious choice, on the reasoning that these URLs carry
+    // ?v= from the layout and so a hit is always the right file. They don't: the
+    // version renders empty (see the note in TexasHoldem.cshtml), so every release
+    // reuses the same URLs. Cache-first against unversioned URLs is how a tool gets
+    // frozen on a build from three months ago with no way for anyone to tell. This
+    // strategy needs no version to be correct: worst case a dealer is one launch
+    // behind, which for a tool that runs entirely in the browser is nothing.
+    if (!CACHEABLE.has(request.destination)) return;
+
+    event.respondWith((async () => {
+        const cache = await caches.open(CACHE);
+        const cached = await cache.match(request);
+
+        const fresh = fetch(request).then(res => {
+            if (res.ok) cache.put(request, res.clone());
+            return res;
+        }).catch(() => null);
+
+        if (cached) return cached;
+        const res = await fresh;
+        if (res) return res;
+        throw new Error("offline and not cached: " + request.url);
+    })());
+});

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

@@ -90,6 +90,21 @@ input[type="number"] {
     font-variant-numeric: tabular-nums;
 }
 
+/* Read aloud, never drawn. `display: none` and `visibility: hidden` both take an
+   element out of the accessibility tree along with the layout, which would silence the
+   live region entirely — so it stays in the tree at 1px, clipped. */
+.visuallyHidden {
+    position: absolute;
+    width: 1px;
+    height: 1px;
+    margin: -1px;
+    padding: 0;
+    overflow: hidden;
+    clip-path: inset(50%);
+    white-space: nowrap;
+    border: 0;
+}
+
 /* Hold the scrollbar's width whether or not there is one to show. A panel opening far
    enough to make the page scrollable used to narrow the viewport by the scrollbar's
    width, which re-centres the felt and nudges every line of text left. No effect on

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

@@ -142,6 +142,52 @@ const ActionBar = {
         }
 
         this.syncTankTimer();
+        this.announce();
+    },
+
+    // One sentence, for anyone running this by ear.
+    //
+    // The bar used to carry aria-live itself, and because render() rebuilds the whole
+    // thing every action, a screen reader read the lot out after every tap — street,
+    // pot, player count, who's short, the clock, the undo label and all three buttons.
+    // Nothing in that is wrong; it is just unusable at the speed a hand is dealt.
+    //
+    // What a dealer actually needs from the tool between taps is who is on the clock
+    // and what it costs them. That is what this says, into a small element that exists
+    // from page load and only ever has its text replaced.
+    //
+    // Guarded on the sentence itself rather than on the state, because render() is
+    // called for a great many reasons that don't change whose turn it is — resizing the
+    // window, opening a panel, editing a note — and a live region that repeats itself
+    // is read out again every time.
+    announce() {
+        const target = document.getElementById("actionAnnouncer");
+        if (!target) return;
+
+        const said = this.announcement();
+        if (said === this.lastAnnouncement) return;
+        this.lastAnnouncement = said;
+        target.textContent = said;
+    },
+
+    announcement() {
+        const state = this.state;
+        if (!state.bettingOpen) {
+            const preview = Betting.blindPreview(state);
+            return preview ? "Ready to deal." : "";
+        }
+        if (Betting.isHandOver(state)) return "Hand over. Resolve the pot.";
+
+        const index = state.actingSeatIndex;
+        if (index === null || index === undefined) {
+            return `${Betting.streetLabel(state.street)} betting is done.`;
+        }
+
+        const player = state.seats[index];
+        const name = HoldemState.displayName(player, index);
+        const owed = Betting.toCall(state, player);
+        const cost = owed > 0 ? `${Money.format(owed)} to call` : "checked to them";
+        return `${name} to act, ${cost}. Pot ${Money.format(Betting.potSoFar(state))}.`;
     },
 
     renderStatus() {

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

@@ -863,4 +863,51 @@ document.addEventListener("DOMContentLoaded", () => {
             "The saved table couldn't be read, so this one started empty.",
             { duration: 12000 });
     }
+
+    // ---- Working with no signal ----
+    //
+    // The night already survives anything — it lives in localStorage — but the page
+    // did not. Reload in a back room with one bar of signal and a dealer with nine
+    // players waiting got a browser error page. The worker below keeps the tool itself
+    // on the phone; see wwwroot/casino/sw.js for what it does and doesn't cache.
+    //
+    // The list of files to keep is read off this document rather than written down in
+    // the worker. Every stylesheet and script the page actually loaded is right here in
+    // the DOM, already carrying the ?v= release string from _Layout — so the list
+    // cannot drift from the markup, which is the way a hand-kept one always fails: it
+    // stays right until somebody adds a script tag, and then the tool is quietly
+    // offline-broken until a dealer finds out the hard way.
+    const registerWorker = () => {
+        if (!("serviceWorker" in navigator)) return;
+
+        const shell = [
+            location.pathname,
+            "/casino/holdem.webmanifest",
+            ...[...document.querySelectorAll('link[rel="stylesheet"][href]')].map(el => el.href),
+            ...[...document.querySelectorAll("script[src]")].map(el => el.src),
+        ].filter(url => new URL(url, location.origin).origin === location.origin);
+
+        navigator.serviceWorker.register("/casino/sw.js", { scope: "/casino/" })
+            .then(reg => {
+                // The worker that will answer for this page — `controller` is still null
+                // on the very first visit, before activate has claimed it.
+                const worker = reg.active || navigator.serviceWorker.controller;
+                if (worker) {
+                    worker.postMessage({ type: "precache", urls: shell });
+                    return;
+                }
+                navigator.serviceWorker.ready.then(ready => {
+                    if (ready.active) ready.active.postMessage({ type: "precache", urls: shell });
+                });
+            })
+            .catch(() => {
+                // No worker means no offline, and nothing else. Every other part of the
+                // tool works exactly as it did, so this is not worth a toast at a table.
+            });
+    };
+
+    // After load, not during it: registering competes with the page's own scripts for
+    // the network, and the first paint matters more than the second visit does.
+    if (document.readyState === "complete") registerWorker();
+    else window.addEventListener("load", registerWorker, { once: true });
 });

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

@@ -386,11 +386,53 @@ const Render = {
         return HoldemState.displayName(player, seatIndex);
     },
 
+    // Builds the pucks once and keeps them. Everything below this line updates the
+    // nodes that are already on the felt.
+    //
+    // A seat's node belongs to its index for as long as the table is that size, so the
+    // listeners can close over the index the way they always did. Only a change in the
+    // number of chairs throws the row away.
+    buildSeatNodes(layer, count) {
+        const template = document.getElementById("seatTemplate");
+        const nodes = [];
+        for (let index = 0; index < count; index++) {
+            const node = template.content.firstElementChild.cloneNode(true);
+            node.dataset.seatIndex = String(index);
+            node.querySelector(".seatChairNumber").textContent = index + 1;
+
+            // Tapping the puck is the same act as "Give the button" in the seat menu,
+            // so it goes through the same hook — otherwise this one path would move
+            // the button without moving the blinds that follow it.
+            node.querySelector(".dealerChip").addEventListener("click", e => {
+                e.stopPropagation();
+                this.hooks.onGiveButton(index);
+            });
+
+            this.wireSeatGestures(node, index);
+            this.wireDragAndDrop(node, index);
+            nodes.push(node);
+        }
+        layer.replaceChildren(...nodes);
+    },
+
+    // Drawing the seats used to mean throwing all of them away and building them again:
+    // `innerHTML = ""`, then a template clone, three sets of event listeners and a
+    // dozen attributes per chair, on every render. Nine seats is ninety nodes, and
+    // renderAll() runs after every single tap a dealer makes.
+    //
+    // Measured on a nine-handed table: renderAll was 12.4ms, of which this function was
+    // 7.3. That is most of a frame gone before the browser has drawn anything, on a
+    // desktop — a phone is several times slower, which is where the tool actually runs
+    // and where a dealer's tap felt like it landed a moment late.
+    //
+    // Nothing about what gets drawn changes here. The pucks are built once and then
+    // updated in place, which is what the rest of this function was already doing to
+    // their contents anyway.
     renderSeats() {
         const layer = document.getElementById("seatsLayer");
-        layer.innerHTML = "";
+        const count = this.state.seats.length;
+        if (layer.childElementCount !== count) this.buildSeatNodes(layer, count);
         this.updateSeatDensity();
-        const template = document.getElementById("seatTemplate");
         const { dealerIndex, sbIndex, bbIndex, manual: manualBlinds } = HoldemState.getBlindSeats(this.state);
         // A button on an empty chair normally means the table has drifted and wants
         // fixing. Once it's the dead button it means the opposite — it's exactly where
@@ -400,11 +442,11 @@ const Render = {
             !this.state.seats[dealerIndex].inHand;
 
         this.state.seats.forEach((player, index) => {
-            const node = template.content.firstElementChild.cloneNode(true);
+            const node = layer.children[index];
+            if (!node) return;
             const pos = this.seatPosition(index, this.state.seatCount);
             node.style.left = `${pos.left}%`;
             node.style.top = `${pos.top}%`;
-            node.dataset.seatIndex = String(index);
 
             // Which side of the seat the pot is on, which is the side its bet chip
             // arrives from — the chip sits on the same spoke, closer in. For a seat on
@@ -416,7 +458,8 @@ const Render = {
             // telling the dealer who the big blind is was simply gone.
             node.classList.toggle("seatBelowCentre", pos.top > 50);
 
-            node.querySelector(".seatChairNumber").textContent = index + 1;
+            // The chair number is set once, in buildSeatNodes — a seat's index is the
+            // one thing about it that cannot change while the node exists.
 
             const dealerChip = node.querySelector(".dealerChip");
             const hasButton = index === dealerIndex;
@@ -440,13 +483,6 @@ const Render = {
                 : `Give the dealer button to ${who}`;
             dealerChip.setAttribute("aria-label", chipLabel);
             dealerChip.title = chipLabel;
-            // Tapping the puck is the same act as "Give the button" in the seat menu,
-            // so it goes through the same hook — otherwise this one path would move
-            // the button without moving the blinds that follow it.
-            dealerChip.addEventListener("click", e => {
-                e.stopPropagation();
-                this.hooks.onGiveButton(index);
-            });
 
             const sbBadge = node.querySelector(".sbBadge");
             const bbBadge = node.querySelector(".bbBadge");
@@ -471,11 +507,6 @@ const Render = {
 
             this.updatePuckContent(node, player, index);
             node.classList.toggle("seatSelected", index === this.selectedSeatIndex);
-
-            this.wireSeatGestures(node, index);
-            this.wireDragAndDrop(node, index);
-
-            layer.appendChild(node);
         });
 
         this.renderBets();

tests/holdem/announcing.test.js

@@ -0,0 +1,125 @@
+// What the tool says out loud between taps.
+//
+// The action bar carried `aria-live="polite"` on the element whose entire contents
+// render() rebuilds every action, so a screen reader read the whole bar after every
+// single tap. Measured, after one:
+//
+//   "PRE-FLOP Pot $15 9 players Bob · $250 behind 0:00 ↶ dealing the hand U
+//    Fold Call $10 Raise"
+//
+// Nothing in that is wrong. It is just unusable at the speed a hand is dealt, and it
+// is the documented anti-pattern: a live region has to be a stable element whose text
+// changes, not a container that gets replaced.
+//
+// What a dealer running this by ear needs is who is on the clock and what it costs
+// them. These are the sentences.
+const test = require("node:test");
+const { describe } = require("node:test");
+const assert = require("node:assert");
+const { ActionBar, Betting, HoldemState, makeTable } = require("./load");
+
+const barOn = (state) => {
+    ActionBar.state = state;
+    ActionBar.lastAnnouncement = undefined;
+    return ActionBar;
+};
+
+describe("before the cards are out", () => {
+    test("a table that could be dealt says so", () => {
+        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3] });
+        assert.equal(barOn(state).announcement(), "Ready to deal.");
+    });
+
+    test("and an empty table says nothing at all", () => {
+        const state = HoldemState.createDefault();
+        assert.equal(barOn(state).announcement(), "");
+    });
+});
+
+describe("while a hand is running", () => {
+    const dealt = () => {
+        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], smallBlind: 1, bigBlind: 2 });
+        state.seats.forEach((p, i) => { p.name = ["Ann", "Ben", "Cal", "Dee"][i] || ""; });
+        Betting.beginHand(state);
+        return state;
+    };
+
+    test("names who is on the clock, what it costs, and the pot", () => {
+        const state = dealt();
+        const said = barOn(state).announcement();
+        assert.match(said, /to act/);
+        assert.match(said, /\$2 to call/);
+        assert.match(said, /Pot \$3\./);
+    });
+
+    test("it is the seat that is actually acting, not the one after it", () => {
+        const state = dealt();
+        const name = HoldemState.displayName(state.seats[state.actingSeatIndex], state.actingSeatIndex);
+        assert.ok(barOn(state).announcement().startsWith(name + " to act"));
+    });
+
+    test("says checked to them rather than $0 to call", () => {
+        // A number nobody owes is a number a dealer has to stop and parse.
+        const state = dealt();
+        state.currentBet = 0;
+        assert.match(barOn(state).announcement(), /checked to them/);
+        assert.doesNotMatch(barOn(state).announcement(), /\$0 to call/);
+    });
+
+    test("a street with nobody left to act says the street is done", () => {
+        const state = dealt();
+        state.actingSeatIndex = null;
+        state.street = "flop";
+        assert.equal(barOn(state).announcement(), "Flop betting is done.");
+    });
+
+    test("and a finished hand points at the pot", () => {
+        const state = dealt();
+        state.seats.forEach((p, i) => { if (i !== 0) p.folded = true; });
+        assert.equal(Betting.isHandOver(state), true);
+        assert.equal(barOn(state).announcement(), "Hand over. Resolve the pot.");
+    });
+});
+
+describe("how often it speaks", () => {
+    // A live region that is handed the same sentence twice reads it out twice, and
+    // render() runs for a great many reasons that have nothing to do with whose turn
+    // it is — a resize, a panel opening, a note being typed.
+    const stubTarget = () => {
+        const el = { textContent: "" };
+        global.document = { getElementById: id => (id === "actionAnnouncer" ? el : null) };
+        return el;
+    };
+
+    test("says nothing new when nothing changed", () => {
+        const el = stubTarget();
+        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], smallBlind: 1, bigBlind: 2 });
+        Betting.beginHand(state);
+        const bar = barOn(state);
+
+        bar.announce();
+        const first = el.textContent;
+        assert.ok(first.length > 0);
+
+        el.textContent = "CLEARED";       // if announce() writes again, this comes back
+        bar.announce();
+        assert.equal(el.textContent, "CLEARED", "the same sentence was not written twice");
+        delete global.document;
+    });
+
+    test("but does when the action moves", () => {
+        const el = stubTarget();
+        const state = makeTable({ seatCount: 6, seated: [0, 1, 2, 3], smallBlind: 1, bigBlind: 2 });
+        Betting.beginHand(state);
+        const bar = barOn(state);
+
+        bar.announce();
+        const first = el.textContent;
+        Betting.call(state, state.actingSeatIndex);
+        bar.announce();
+
+        assert.notEqual(el.textContent, first);
+        assert.match(el.textContent, /to act/);
+        delete global.document;
+    });
+});