'use strict';
const assert = require('node:assert/strict');
const vm = require('node:vm');
const {script, loader} = JSON.parse(require('node:fs').readFileSync(process.argv[2], 'utf8'));
const token = 'a'.repeat(64);
const json = value => new Response(JSON.stringify(value));
const session = (extra = {}) => json({username: '<img>', role: 'user', csrf: token, expires_in: 3600, ...extra});
const ticket = () => json({ticket: 't'.repeat(32)});
const serialSettings = (extra = {}) => ({running: true, baud: 230400, data_bits: '8', parity: 'none',
    stop_bits: '1', flow: 'rts-cts', dtr: 'on-connect', rts_threshold: 96, ...extra});
const failure = status => new Response('SECRET ERROR BODY', {status, headers: {'Retry-After': '7'}});
const deferred = () => { let resolve; const promise = new Promise(r => { resolve = r; }); return {promise, resolve}; };
const tick = async () => { for (let i = 0; i < 6; ++i) await new Promise(r => setImmediate(r)); };
function browser({onlyLoader = false, withLoader = false, role = 'user'} = {}) {
    const nodes = {}, events = {}, calls = [], redirects = [], timers = new Map(), sockets = [], terminals = [];
    const queues = {'/api/session': [], '/api/status': [], '/api/ws-ticket': [], '/api/admin/ws-ticket': [], '/api/logout': [], '/api/settings/serial': [], '/api/settings/serial-operation': []};
    const fits = [];
    let serial = 0, now = Date.now();
    class Clock extends Date { static now() { return now; } }
    const on = (key, fn) => { if (!(events[key] ||= []).includes(fn)) events[key].push(fn); };
    const emit = (key, event = {}) => { for (const fn of events[key] || []) fn(event); };
    const timeout = (fn, ms, interval = false) => { timers.set(++serial, {fn, ms, interval}); return serial; };
    class Socket {
        static OPEN = 1;
        constructor(url) { this.url = url; this.readyState = 0; this.bufferedAmount = 0; this.events = {}; this.sent = []; sockets.push(this); }
        addEventListener(k, fn) { this.events[k] = fn; }
        emit(k, event = {}) { if (k === 'open') this.readyState = 1; this.events[k]?.(event); this['on' + k]?.(event); }
        close() { this.closed = true; this.readyState = 3; this.emit('close'); }
        send(value) { this.sent.push(value); }
    }
    class Terminal {
        constructor(options) { this.options = options; this.writes = []; terminals.push(this); }
        loadAddon() {} open() {} focus() {} resize(cols, rows) { this.cols = cols; this.rows = rows; } onData(fn) { this.input = fn; }
        write(bytes, callback) { this.writes.push([...bytes]); if (this.holdWrites) (this.pending ||= []).push(callback); else callback?.(); }
    }
    const window = {confirm: () => true, addEventListener: on, removeEventListener(k, fn) { events[k] = (events[k] || []).filter(f => f !== fn); },
        setTimeout: timeout, clearTimeout: id => timers.delete(id),
        setInterval: (fn, ms) => timeout(fn, ms, true), clearInterval: id => timers.delete(id),
        requestAnimationFrame: fn => timeout(fn, -1), cancelAnimationFrame: id => timers.delete(id),
        location: {origin: 'https://sak.local', replace: path => redirects.push(path)}};
    const context = vm.createContext({window, document: {getElementById(id) {
        return nodes[id] ||= {textContent: '', dataset: {}, classList: {toggle() {}},
            setAttribute(k, v) { this[k] = v; },
            getBoundingClientRect: () => ({width: 100, height: 100}),
            addEventListener(k, fn) { this[k] = fn; }};
    }}, Terminal, FitAddon: {FitAddon: class {
        constructor() { this.measurements = []; this.calls = 0; fits.push(this); }
        proposeDimensions() { ++this.calls; return this.measurements.length ? this.measurements.shift() : {cols: 80, rows: 24}; }
    }},
    TextEncoder, TextDecoder, Uint8Array, ArrayBuffer, AbortController, URL, Date: Clock, performance: {now: () => now}, WebSocket: Socket,
    fetch: async (url, options) => {
        // Apply the Origin regression guard to every mutation, including logout.
        assert.ok(Object.hasOwn(queues, url));
        if (options.method === 'POST') assert.equal(options.mode, 'cors');
        assert.equal(options.headers?.Origin, undefined);
        calls.push({url, ...options});
        const next = queues[url].shift();
        if (next !== undefined) return typeof next === 'function' ? next(options) : next;
        if (url === '/api/session') return session({role});
        if (url === '/api/status') return json({});
        if (url === '/api/settings/serial') return json(serialSettings());
        if (url === '/api/ws-ticket') return ticket();
        if (url === '/api/admin/ws-ticket') return json({ticket: '0123456789abcdef'.repeat(4), expires_in: 30});
        throw new Error('network unavailable');
    }});
    if (withLoader || onlyLoader) vm.runInContext(loader, context);
    const start = () => vm.runInContext(script, context);
    const fire = ms => {
        const match = [...timers].find(([, t]) => t.ms === ms); assert.ok(match, `missing timer ${ms}`);
        const [id, t] = match; if (!t.interval) timers.delete(id); t.fn();
    };
    return {nodes, calls, redirects, timers, sockets, terminals, queues, fits, events, emit, start, fire,
        click: id => nodes[id].click(), elapse: ms => { now += ms; }, window};
}
async function connected() { const b = browser(); b.start(); await tick(); assert.equal(b.sockets.length, 1); return b; }
let passed = 0;
async function test(name, fn) { await fn(); ++passed; console.log('PASS JS:', name); }
(async () => {
    await test('bootstrap, CSRF, bounded expiry safe text, serial protocol and disconnect pause', async () => {
        const b = await connected();
        assert.equal(b.calls[0].url, '/api/session');
        const post = b.calls.find(c => c.url === '/api/ws-ticket');
        assert.equal(post.method, 'POST'); assert.equal(post.body, ''); assert.equal(post.headers['X-CSRF-Token'], token);
        for (const call of b.calls) for (const [k, v] of Object.entries({credentials: 'same-origin', mode: call.method === 'POST' ? 'cors' : 'same-origin', cache: 'no-store', redirect: 'error'})) assert.equal(call[k], v);
        assert.match(b.nodes['session-info'].textContent, /^<img>.*one hour absolute/);
        const ws = b.sockets[0], term = b.terminals[0]; ws.emit('open');
        ws.emit('message', {data: JSON.stringify({type: 'hello', clientId: 8, writerId: 8, role: 'writer'})});
        term.input('x'.repeat(2050)); assert.deepEqual(ws.sent.map(x => x.length), [1024, 1024, 2]);
        ws.emit('message', {data: Uint8Array.of(0, 255, 13, 10).buffer}); assert.deepEqual(term.writes, [[0, 255, 13, 10]]);
        b.click('release-control'); assert.equal(ws.sent.at(-1), 'release-writer');
        ws.emit('message', {data: JSON.stringify({type: 'writer', writerId: 0, role: 'observer'})});
        b.click('request-control'); assert.equal(ws.sent.at(-1), 'request-writer');
        b.click('connection-toggle'); assert.ok(ws.closed); assert.equal(b.nodes['connection-toggle'].textContent, 'Connect');
        const count = b.calls.length; ws.emit('close'); await tick(); assert.equal(b.calls.length, count);
        b.click('connection-toggle'); await tick(); assert.equal(b.calls[count].url, '/api/session');
    });
    await test('401 at session/ticket/status stops everything and navigates only once', async () => {
        for (const path of ['/api/session', '/api/ws-ticket', '/api/status']) {
            const b = browser(); b.queues[path].push(failure(401)); b.start(); await tick();
            assert.deepEqual(b.redirects, ['/login']); assert.ok(b.sockets.every(s => s.closed));
            assert.equal(b.timers.size, 0); b.window.sakSessionExpired(); assert.equal(b.redirects.length, 1);
            b.click('connection-toggle'); await tick(); assert.equal(b.redirects.length, 1);
        }
    });
    await test('403 mutation is manual-only; capacity backoff is not credentials and revalidates', async () => {
        for (const status of [403, 429, 503]) {
            const b = browser(); b.queues['/api/ws-ticket'].push(failure(status)); b.start(); await tick();
            assert.deepEqual(b.redirects, []); assert.equal(b.sockets.length, 0);
            if (status === 403) {
                assert.match(b.nodes['connection-detail'].textContent, /security check/);
                assert.equal(b.nodes['connection-toggle'].textContent, 'Connect'); b.click('connection-toggle');
            } else {
                assert.match(b.nodes['connection-detail'].textContent, /capacity or backoff/); b.fire(7000);
            }
            await tick(); assert.equal(b.calls.filter(c => c.url === '/api/session').length, 2);
            assert.equal(b.sockets.length, 1);
        }
    });
    await test('logout success, lost success, uncertain network and explicit recovery', async () => {
        for (const outcome of ['204', 'lost401', 'lost200', 'offline', '403', '503']) {
            const b = await connected();
            b.queues['/api/logout'].push(outcome === '204' ? new Response(null, {status: 204}) :
                ['403', '503'].includes(outcome) ? failure(Number(outcome)) : () => { throw new Error('SECRET NETWORK'); });
            if (outcome === 'lost401') b.queues['/api/session'].push(session(), failure(401));
            if (outcome === 'offline') b.queues['/api/session'].push(session(), () => { throw new Error('offline'); });
            await b.click('sign-out'); await tick(); assert.ok(b.sockets[0].closed);
            assert.equal(b.calls.filter(c => c.url === '/api/logout').length, 1);
            const post = b.calls.find(c => c.url === '/api/logout'); assert.equal(post.body, ''); assert.equal(post.headers['X-CSRF-Token'], token);
            if (['204', 'lost401'].includes(outcome)) { assert.deepEqual(b.redirects, ['/login']); assert.equal(b.timers.size, 0); }
            else {
                assert.deepEqual(b.redirects, []); assert.match(b.nodes['connection-status'].textContent, /not confirmed/);
                assert.ok(!b.nodes['connection-detail'].textContent.includes('SECRET'));
                assert.equal(b.nodes['sign-out'].disabled, false);
                const count = b.calls.length; b.click('connection-toggle'); await tick(); assert.equal(b.calls[count].url, '/api/session');
                assert.equal(b.sockets.length, 2);
            }
        }
    });
    await test('logout cancels pending status/ticket/session; late 401 and WS events cannot affect new work', async () => {
        for (const path of ['/api/session', '/api/ws-ticket', '/api/status']) {
            const d = deferred(), b = browser(); b.queues[path].push(d.promise); b.start(); await tick();
            b.queues['/api/logout'].push(failure(403)); await b.click('sign-out'); await tick();
            assert.ok(b.calls.find(c => c.url === path).signal.aborted);
            const detail = b.nodes['connection-detail'].textContent;
            d.resolve(failure(401)); await tick(); assert.deepEqual(b.redirects, []); assert.equal(b.nodes['connection-detail'].textContent, detail);
        }
        const b = await connected(), old = b.sockets[0]; b.click('connection-toggle'); b.click('connection-toggle'); await tick();
        old.emit('open'); old.emit('message', {data: JSON.stringify({type: 'hello', clientId: 99, writerId: 99, role: 'writer'})}); old.emit('error'); old.emit('close');
        assert.equal(b.nodes['client-id'].textContent, '—'); assert.equal(b.terminals[0].options.disableStdin, true);
    });
    await test('pagehide/restore revalidates, preserves pause; late logout cannot navigate restored page', async () => {
        for (const paused of [false, true]) {
            const b = await connected(); if (paused) b.click('connection-toggle');
            b.emit('pagehide'); const count = b.calls.length; b.emit('pageshow', {persisted: true}); await tick();
            assert.equal(b.calls[count].url, '/api/session'); assert.equal(b.sockets.length, paused ? 1 : 2);
            if (paused) assert.equal(b.nodes['connection-toggle'].textContent, 'Connect');
        }
        const b = await connected(), d = deferred(); b.queues['/api/logout'].push(d.promise);
        const pending = b.click('sign-out'); await tick(); b.emit('pagehide'); b.emit('pageshow', {persisted: true}); await tick();
        d.resolve(new Response(null, {status: 204})); await pending; assert.deepEqual(b.redirects, []);
    });
    await test('bounded schema/body validation, timeout, expiry and retry session checks', async () => {
        for (const response of [session({csrf: 'A'.repeat(64)}), session({expires_in: 3601}), session({expires_in: -1}),
            session({expires_in: 1.5}), session({role: 'root'}), session({username: 'x'.repeat(17)}),
            new Response(' '.repeat(513)), new Response(Uint8Array.of(255)), json(null)]) {
            const b = browser(); b.queues['/api/session'].push(response); b.start(); await tick();
            assert.equal(b.sockets.length, 0); assert.equal(b.calls.length, 1); assert.ok(b.calls[0].signal.aborted);
        }
        const b = browser(); b.queues['/api/session'].push(o => new Promise((_, reject) => o.signal.addEventListener('abort', () => reject(new Error('timeout')))));
        b.start(); b.fire(15000); await tick(); b.fire(1000); await tick(); assert.equal(b.calls[1].url, '/api/session');
        const c = browser(); c.queues['/api/session'].push(session({expires_in: 2})); c.start(); await tick();
        const expiry = [...c.timers.values()].find(timer => timer.ms >= 0 && timer.ms <= 2000);
        assert.ok(expiry); c.fire(expiry.ms); assert.deepEqual(c.redirects, ['/login']);
    });
    await test('late body completions and superseded restore session are ignored', async () => {
        for (const path of ['/api/session', '/api/ws-ticket', '/api/status']) {
            let stream;
            const b = browser(); b.queues[path].push(new Response(new ReadableStream({start(c) { stream = c; }})));
            b.start(); await tick(); b.emit('pagehide');
            const text = path === '/api/session' ? {username: 'late', role: 'admin', csrf: token, expires_in: 3600} :
                path === '/api/ws-ticket' ? {ticket: 't'.repeat(32)} : {wifi: {available: true, state: 'LATE'}};
            stream.enqueue(new TextEncoder().encode(JSON.stringify(text))); stream.close(); await tick();
            assert.ok(b.sockets.every(socket => socket.closed)); assert.deepEqual(b.redirects, []); assert.equal(b.timers.size, 0);
            assert.ok(!b.nodes['wifi-summary'].textContent.includes('LATE'));
        }
        const b = await connected(); b.click('connection-toggle'); b.emit('pagehide');
        const d = deferred(); b.queues['/api/session'].push(d.promise);
        b.emit('pageshow', {persisted: true}); await tick(); b.click('connection-toggle'); await tick();
        d.resolve(failure(401)); await tick(); assert.deepEqual(b.redirects, []); assert.equal(b.sockets.length, 2);
    });
    await test('inline asset failures: 401 login, offline usable fallback, pagehide and shared navigation guard', async () => {
        for (const status of [401, 503]) {
            const b = browser({onlyLoader: true}); b.queues['/api/session'].push(failure(status));
            b.emit('error', {target: {tagName: 'SCRIPT'}}); await tick();
            assert.deepEqual(b.redirects, status === 401 ? ['/login'] : []); assert.equal(b.timers.size, 0);
            b.emit('error', {target: {tagName: 'SCRIPT'}}); assert.equal(b.calls.length, 1);
        }
        const b = browser({onlyLoader: true}), d = deferred(); b.queues['/api/session'].push(d.promise);
        b.emit('error', {target: {tagName: 'LINK'}}); b.emit('pagehide'); d.resolve(failure(401)); await tick(); assert.deepEqual(b.redirects, []);
        const c = browser({withLoader: true}); c.start(); await tick();
        c.queues['/api/session'].push(failure(401)); c.emit('error', {target: {tagName: 'IMG'}}); await tick();
        assert.deepEqual(c.redirects, ['/login']); assert.ok(c.sockets[0].closed); assert.equal(c.timers.size, 0);
    });
    async function adminBrowser() {
        const b = browser({role: 'admin'}); b.queues['/api/session'].push(session({role: 'admin'}));
        b.start(); await tick(); const ws = b.sockets[0]; ws.emit('open');
        ws.emit('message', {data: JSON.stringify({type: 'hello', clientId: 8, writerId: 8, role: 'writer'})});
        b.click('select-admin'); b.click('admin-toggle'); await tick();
        assert.equal(b.sockets.length, 2); b.sockets[1].emit('open'); return b;
    }
    await test('ordinary user is serial-only; admin selection preserves socket/lease and isolates input/output', async () => {
        const u = await connected(); assert.equal(u.nodes['terminal-selector'].hidden, true);
        u.click('select-admin'); u.click('admin-toggle'); await tick(); assert.equal(u.terminals.length, 1); assert.equal(u.sockets.length, 1);
        const b = await adminBrowser(), [serial, admin] = b.sockets, [st, at] = b.terminals;
        assert.equal(admin.url, 'wss://sak.local/ws/admin?ticket=' + '0123456789abcdef'.repeat(4));
        assert.equal(b.calls.find(c => c.url === '/api/admin/ws-ticket').headers['X-CSRF-Token'], token);
        st.input('WRONG'); at.input('x'.repeat(1025)); assert.equal(serial.sent.length, 0);
        assert.deepEqual(admin.sent.map(x => x.length), [512, 512, 1]);
        serial.emit('message', {data: Uint8Array.of(0, 255).buffer});
        admin.emit('message', {data: Uint8Array.of(27, 91).buffer});
        assert.deepEqual(st.writes, [[0, 255]]); assert.deepEqual(at.writes, [[27, 91]]);
        b.click('release-control'); assert.equal(serial.sent.at(-1), 'release-writer');
        for (let i = 0; i < 20; ++i) { b.click('select-serial'); at.input('WRONG'); b.click('select-admin'); }
        assert.equal(b.sockets.length, 2); assert.equal(b.terminals.length, 2); assert.ok(!serial.closed);
        assert.equal(b.nodes['client-id'].textContent, '8'); assert.equal(b.nodes['writer-id'].textContent, '8');
        assert.equal(b.nodes['release-control'].disabled, false); assert.equal(admin.sent.length, 3);
        b.click('admin-toggle'); assert.ok(admin.closed); assert.equal(admin.onmessage, null); assert.ok(!serial.closed);
        b.click('admin-toggle'); await tick(); const replacement = b.sockets[2]; replacement.emit('open'); replacement.emit('close');
        assert.ok(!serial.closed); assert.equal(b.nodes['admin-toggle'].textContent, 'Open admin');
        b.click('select-serial'); st.input('ok'); assert.deepEqual([...serial.sent.at(-1)], [111, 107]);
    });
    await test('admin rejects serial-format and malformed tickets before upgrade without disturbing serial', async () => {
        for (const value of ['t'.repeat(32), 'a'.repeat(63), 'a'.repeat(65), 'g'.repeat(64), null]) {
            const b = browser({role: 'admin'}); b.start(); await tick();
            const serial = b.sockets[0]; serial.emit('open');
            b.queues['/api/admin/ws-ticket'].push(json({ticket: value}));
            b.click('select-admin'); b.click('admin-toggle'); await tick();
            assert.equal(b.sockets.length, 1); assert.ok(!serial.closed);
            assert.equal(b.nodes['admin-detail'].textContent, 'Admin connection failed. Open admin to retry.');
        }
    });
    await test('bounded hidden output continues draining, separate scrollback and input overflow closes only admin', async () => {
        const b = await adminBrowser(), [serial, admin] = b.sockets, [st, at] = b.terminals;
        assert.equal(st.options.scrollback, 5000); assert.equal(at.options.scrollback, 5000);
        st.holdWrites = true;
        for (let i = 0; i < 65; ++i) serial.emit('message', {data: new Uint8Array(1024).buffer});
        assert.equal(st.writes.length, 64); assert.match(b.nodes['output-detail'].textContent, /serial 1024 B, admin 0 B/);
        st.pending.shift()(); serial.emit('message', {data: Uint8Array.of(42).buffer}); assert.equal(st.writes.at(-1)[0], 42);
        at.input('x'.repeat(4097)); assert.ok(admin.closed); assert.ok(!serial.closed); assert.equal(admin.sent.length, 0);
    });
    await test('admin failures and cancellation are isolated; 401/logout/expiry/pagehide close both', async () => {
        for (const status of [403, 503, 401]) {
            const b = await adminBrowser(), serial = b.sockets[0]; b.click('admin-toggle');
            b.queues['/api/admin/ws-ticket'].push(failure(status)); b.click('admin-toggle'); await tick();
            assert.equal(!!serial.closed, status === 401);
            assert.deepEqual(b.redirects, status === 401 ? ['/login'] : []);
            assert.equal(b.sockets.length, 2);
        }
        for (const action of ['pagehide', 'expiry', 'logout']) {
            const b = await adminBrowser();
            if (action === 'pagehide') b.emit('pagehide');
            if (action === 'expiry') b.window.sakSessionExpired();
            if (action === 'logout') { b.queues['/api/logout'].push(new Response(null, {status: 204})); await b.click('sign-out'); }
            await tick(); assert.ok(b.sockets.every(s => s.closed)); assert.equal(b.sockets[1].onmessage, null);
            if (action === 'pagehide') {
                b.queues['/api/session'].push(session({role: 'admin'})); b.emit('pageshow', {persisted: true}); await tick();
                assert.equal(b.sockets.length, 3); assert.match(b.sockets[2].url, /\/ws\/serial/);
                assert.equal(b.nodes['admin-toggle'].textContent, 'Open admin');
            }
        }
        const b = await adminBrowser(); b.click('admin-toggle'); const d = deferred();
        b.queues['/api/admin/ws-ticket'].push(d.promise); b.click('admin-toggle'); await tick();
        b.click('admin-toggle'); d.resolve(failure(401)); await tick();
        assert.deepEqual(b.redirects, []); assert.ok(!b.sockets[0].closed); assert.equal(b.sockets.length, 2);
    });
    await test('selected resize, listener cleanup, admin handshake deadline and stale callback fencing', async () => {
        const b = await adminBrowser(), [serial, old] = b.sockets;
        b.fire(-1); assert.equal(b.terminals[1].cols, 80); assert.equal(b.terminals[0].cols, undefined);
        b.click('select-serial'); b.fire(-1); assert.equal(b.terminals[0].rows, 24);
        const stale = old.onmessage;
        b.click('select-admin'); b.click('admin-toggle'); b.click('admin-toggle'); await tick();
        stale({data: Uint8Array.of(99).buffer}); assert.equal(b.terminals[1].writes.length, 0);
        b.fire(15000); assert.ok(b.sockets[2].closed); assert.ok(!serial.closed);
        assert.match(b.nodes['admin-detail'].textContent, /timed out/);
        for (let i = 0; i < 3; ++i) {
            b.emit('pagehide'); assert.equal(b.events.resize.length, 0);
            assert.ok(b.sockets.every(s => s.onmessage === null));
            b.queues['/api/session'].push(session({role: 'admin'}));
            b.emit('pageshow', {persisted: true}); await tick(); assert.equal(b.events.resize.length, 1);
        }
        b.window.sakSessionExpired(); assert.equal(b.events.resize.length, 0);
    });
    await test('changed session identity replaces document before adoption, including live admin and paused restore', async () => {
        const identities = [
            {username: 'other-admin', role: 'admin', csrf: 'b'.repeat(64)},
            {username: 'other-user', role: 'user', csrf: 'b'.repeat(64)},
            {role: 'admin', csrf: 'b'.repeat(64)}, // Same account, different login session.
            {username: 'other-admin', role: 'admin'}, // Principal fields are checked independently.
            {role: 'user'}
        ];
        for (const identity of identities) for (const route of ['restore', 'paused-restore', 'live', 'logout']) {
            const b = await adminBrowser(), [serial, admin] = b.sockets;
            serial.emit('message', {data: Uint8Array.of(65).buffer});
            admin.emit('message', {data: Uint8Array.of(66).buffer});
            const stale = admin.onmessage, info = b.nodes['session-info'].textContent;
            const count = b.calls.length;
            b.queues['/api/session'].push(session(identity));
            if (route.includes('restore')) {
                if (route === 'paused-restore') b.click('connection-toggle');
                b.emit('pagehide');
                assert.equal(b.nodes.terminal.hidden, true); assert.equal(b.nodes['admin-terminal'].hidden, true);
                b.emit('pageshow', {persisted: true}); b.click('select-admin');
                assert.equal(b.nodes['admin-terminal'].hidden, true);
            } else if (route === 'live') {
                b.click('connection-toggle'); assert.ok(!admin.closed); b.click('connection-toggle');
            } else await b.click('sign-out');
            await tick();
            assert.deepEqual(b.redirects, ['/']); assert.ok(serial.closed && admin.closed);
            assert.equal(b.nodes['session-info'].textContent, info); // B was never adopted into A's document.
            assert.equal(b.nodes.terminal.hidden, true); assert.equal(b.nodes['admin-terminal'].hidden, true);
            assert.deepEqual(b.calls.slice(count).map(c => c.url), ['/api/session']);
            assert.equal(b.timers.size, 0); assert.equal(b.events.resize.length, 0);
            stale({data: Uint8Array.of(67).buffer}); b.terminals[1].input('WRONG');
            b.click('select-admin'); b.click('admin-toggle'); b.emit('pageshow', {persisted: true});
            assert.deepEqual(b.terminals[1].writes, [[66]]); assert.equal(admin.sent.length, 0);
            assert.equal(b.nodes['admin-terminal'].hidden, true); assert.equal(b.sockets.length, 2);
        }
    });
    await test('same-session restore preserves both scrollbacks; pending validation never reveals them', async () => {
        for (const paused of [false, true]) {
            const b = await adminBrowser();
            b.sockets[0].emit('message', {data: Uint8Array.of(65).buffer});
            b.sockets[1].emit('message', {data: Uint8Array.of(66).buffer});
            if (paused) b.click('connection-toggle');
            b.emit('pagehide'); const d = deferred(); b.queues['/api/session'].push(d.promise);
            b.emit('pageshow', {persisted: true}); await tick(); b.click('select-serial'); b.click('select-admin');
            assert.equal(b.nodes.terminal.hidden, true); assert.equal(b.nodes['admin-terminal'].hidden, true);
            d.resolve(session({role: 'admin', expires_in: 3500})); await tick();
            assert.deepEqual(b.redirects, []); assert.equal(b.terminals.length, 2);
            assert.deepEqual(b.terminals.map(t => t.writes), [[[65]], [[66]]]);
            assert.equal(b.nodes['admin-terminal'].hidden, false); assert.equal(b.sockets.length, paused ? 2 : 3);
        }
        const b = await adminBrowser(), admin = b.sockets[1];
        admin.emit('message', {data: Uint8Array.of(66).buffer});
        b.click('connection-toggle'); b.click('connection-toggle'); await tick();
        assert.ok(!admin.closed); assert.deepEqual(b.redirects, []); assert.deepEqual(b.terminals[1].writes, [[66]]);
    });
    await test('undefined first fit retries unchanged bounds, stops after three retries and fences stale work', async () => {
        const b = await adminBrowser(), fit = b.fits[1];
        fit.measurements.push(undefined); b.fire(-1);
        assert.equal(b.terminals[1].cols, undefined); b.fire(-1);
        assert.equal(b.terminals[1].cols, 80); assert.equal(fit.calls, 2);
        b.emit('resize'); b.fire(-1); assert.equal(fit.calls, 2); // Successful measurement is cached.
        b.click('select-serial'); b.click('select-admin');
        fit.measurements.push(undefined, undefined, undefined, undefined);
        for (let i = 0; i < 4; ++i) b.fire(-1);
        assert.equal(fit.calls, 6); assert.ok(![...b.timers.values()].some(t => t.ms === -1));
        b.emit('resize'); b.fire(-1); assert.equal(fit.calls, 7); // Failed bounds were never cached.
        for (const action of ['pagehide', 'expiry', 'logout']) {
            const c = await adminBrowser(); c.fits[1].measurements.push(undefined); c.fire(-1);
            const stale = [...c.timers.values()].find(t => t.ms === -1).fn;
            if (action === 'pagehide') c.emit('pagehide');
            if (action === 'expiry') c.window.sakSessionExpired();
            if (action === 'logout') { c.queues['/api/logout'].push(failure(403)); await c.click('sign-out'); }
            await tick(); stale(); assert.equal(c.fits[1].calls, 1);
            assert.ok(![...c.timers.values()].some(t => t.ms === -1));
            if (action === 'pagehide') {
                c.emit('pageshow', {persisted: true}); await tick(); stale();
                assert.equal(c.fits[1].calls, 1); c.fire(-1); assert.equal(c.fits[1].calls, 2);
            }
        }
    });
    await test('Settings is admin-only, read-only, bounded and preserves both sockets, lease and hidden output', async () => {
        const u = await connected(); u.click('select-settings'); u.click('refresh-settings'); await tick();
        assert.ok(!u.calls.some(c => c.url === '/api/settings/serial'));
        const b = await adminBrowser(), [serial, admin] = b.sockets;
        assert.ok(!b.calls.some(c => c.url === '/api/settings/serial'));
        for (let i = 0; i < 10; ++i) {
            b.click('select-settings'); await tick();
            assert.equal(b.nodes['serial-settings'].hidden, false);
            assert.equal(b.nodes.terminal.hidden, true); assert.equal(b.nodes['admin-terminal'].hidden, true);
            assert.equal(b.nodes['settings-values'].hidden, false);
            assert.equal(b.nodes['setting-baud'].textContent, '230400');
            assert.equal(b.nodes['setting-dtr'].textContent, 'on-connect');
            assert.equal(b.nodes['setting-running'].textContent, 'Running');
            b.terminals.forEach(t => { assert.equal(t.options.disableStdin, true); t.input('WRONG'); });
            serial.emit('message', {data: Uint8Array.of(65).buffer}); admin.emit('message', {data: Uint8Array.of(66).buffer});
            b.click('select-serial'); b.click('select-admin');
        }
        assert.equal(b.sockets.length, 2); assert.ok(!serial.closed && !admin.closed);
        assert.equal(serial.sent.length, 0); assert.equal(admin.sent.length, 0);
        assert.equal(b.nodes['client-id'].textContent, '8'); assert.equal(b.nodes['writer-id'].textContent, '8');
        assert.equal(b.nodes['release-control'].disabled, false);
        assert.deepEqual(b.terminals.map(t => t.writes.length), [10, 10]);
        const reads = b.calls.filter(c => c.url === '/api/settings/serial');
        assert.equal(reads.length, 10); assert.ok(reads.every(c => c.method === 'GET' && c.body === undefined));
        b.queues['/api/settings/serial'].push(json(serialSettings({running: false, baud: 110, data_bits: '7', parity: 'odd', stop_bits: '2', flow: 'none', dtr: 'inactive', rts_threshold: 1})));
        b.click('select-settings'); await tick(); assert.equal(b.nodes['setting-running'].textContent, 'Stopped');
        b.click('refresh-settings'); await tick(); assert.equal(b.nodes['setting-running'].textContent, 'Running');
    });
    await test('Settings rejects malformed/oversized schemas, contains errors, and retries only explicitly', async () => {
        for (const response of [json(null), json(serialSettings({secret: 'bad'})), json(serialSettings({baud: 1000001})),
            json(serialSettings({running: 1})), json(serialSettings({parity: '<img>'})), json(serialSettings({rts_threshold: 0})),
            new Response(' '.repeat(257)), new Response(Uint8Array.of(255)), failure(400), failure(403), failure(404), failure(429), failure(503)]) {
            const b = await adminBrowser(); b.queues['/api/settings/serial'].push(response);
            b.click('select-settings'); await tick();
            assert.equal(b.nodes['settings-values'].hidden, true); assert.equal(b.nodes['setting-baud'].textContent, '');
            assert.match(b.nodes['settings-detail'].textContent, /Refresh to retry/);
            assert.ok(!b.nodes['settings-detail'].textContent.includes('SECRET'));
            assert.equal(b.nodes['refresh-settings'].disabled, false); assert.ok(b.sockets.every(s => !s.closed));
            assert.equal(b.calls.filter(c => c.url === '/api/settings/serial').length, 1);
            b.click('refresh-settings'); await tick(); assert.equal(b.nodes['settings-values'].hidden, false);
        }
        const b = await adminBrowser();
        b.queues['/api/settings/serial'].push(o => new Promise((_, reject) => o.signal.addEventListener('abort', () => reject(new Error('SECRET timeout')))));
        b.click('select-settings'); await tick(); b.click('refresh-settings');
        assert.equal(b.calls.filter(c => c.url === '/api/settings/serial').length, 1);
        b.fire(15000); await tick(); assert.match(b.nodes['settings-detail'].textContent, /Refresh to retry/);
        assert.ok(b.sockets.every(s => !s.closed));
    });
    await test('Settings cancellation fences late replies; session change, 401, logout and restore clear the view', async () => {
        for (const action of ['switch', 'pagehide', 'expiry', 'logout']) {
            const b = await adminBrowser(), d = deferred(); b.queues['/api/settings/serial'].push(d.promise);
            b.click('select-settings'); await tick(); const call = b.calls.find(c => c.url === '/api/settings/serial');
            if (action === 'switch') b.click('select-serial');
            if (action === 'pagehide') b.emit('pagehide');
            if (action === 'expiry') b.window.sakSessionExpired();
            if (action === 'logout') { b.queues['/api/logout'].push(new Response(null, {status: 204})); await b.click('sign-out'); }
            assert.ok(call.signal.aborted); d.resolve(failure(401)); await tick();
            assert.equal(b.nodes['serial-settings'].hidden, true); assert.equal(b.nodes['setting-baud'].textContent, '');
            if (action === 'switch') { assert.deepEqual(b.redirects, []); assert.ok(b.sockets.every(s => !s.closed)); }
            if (action === 'pagehide') {
                b.emit('pageshow', {persisted: true}); await tick();
                assert.deepEqual(b.redirects, []); assert.equal(b.nodes['settings-values'].hidden, true);
                b.click('refresh-settings'); await tick(); assert.equal(b.nodes['settings-values'].hidden, false);
            }
        }
        for (const change of ['401', 'identity']) {
            const b = await adminBrowser();
            if (change === '401') b.queues['/api/settings/serial'].push(failure(401));
            else b.queues['/api/session'].push(session({role: 'admin', csrf: 'b'.repeat(64)}));
            b.click('select-settings'); await tick();
            assert.deepEqual(b.redirects, [change === '401' ? '/login' : '/']);
            assert.ok(b.sockets.every(s => s.closed)); assert.equal(b.nodes['serial-settings'].hidden, true);
            assert.equal(b.nodes['setting-baud'].textContent, '');
        }
    });
    await test('Settings session validation never strands concurrent serial reconnect; newer admission fences old settings checks', async () => {
        const b = await adminBrowser(), d = deferred();
        b.queues['/api/session'].push(d.promise); b.sockets[0].emit('close'); b.fire(1000); await tick();
        b.click('select-settings'); await tick(); assert.equal(b.nodes['settings-values'].hidden, false);
        d.resolve(session({role: 'admin'})); await tick();
        assert.equal(b.sockets.length, 3); assert.ok(!b.sockets[1].closed);
        const c = await adminBrowser(), old = deferred(); c.queues['/api/session'].push(old.promise);
        c.click('select-settings'); await tick(); c.sockets[0].emit('close'); c.fire(1000); await tick();
        old.resolve(session({role: 'admin'})); await tick();
        assert.equal(c.sockets.length, 3); assert.ok(!c.sockets[1].closed);
        assert.equal(c.nodes['refresh-settings'].disabled, false);
        assert.match(c.nodes['settings-detail'].textContent, /Refresh to retry/);
        c.click('refresh-settings'); await tick(); assert.equal(c.nodes['settings-values'].hidden, false);
    });
    await test('Serial typed actions: draft, confirmation, CSRF, explicit results and working/persisted semantics', async () => {
        const b = browser({role: 'admin'}); b.start(); await tick(); b.sockets[0].emit('open');
        b.click('select-settings'); await tick();
        const path = '/api/settings/serial-operation';
        assert.equal(b.nodes['edit-baud'].value, '230400');
        const baseline = b.calls.length;
        b.nodes['edit-baud'].value = '460800'; assert.equal(b.calls.length, baseline);
        b.window.confirm = () => false; b.click('serial-reset'); await tick(); assert.equal(b.calls.length, baseline);
        b.window.confirm = () => true;
        for (const [i, action] of ['apply', 'save', 'load', 'defaults', 'reset', 'start', 'stop'].entries()) {
            if (i) { b.click('refresh-settings'); await tick(); }
            b.queues[path].push(json({id: i + 1, action, state: 'pending'}));
            b.click('serial-' + action); await tick();
            const post = b.calls.filter(c => c.url === path && c.method === 'POST').at(-1);
            assert.equal(post.headers['X-CSRF-Token'], token); assert.equal(post.headers['Content-Type'], 'application/json');
            assert.ok(Buffer.byteLength(post.body) <= 256);
            const payload = JSON.parse(post.body); assert.equal(payload.action, action);
            if (action === 'apply') {
                assert.equal(payload.baud, 460800); assert.equal(payload.rts_threshold, 96); assert.equal(Object.keys(payload).length, 8);
            } else assert.deepEqual(payload, {action});
            assert.ok(b.nodes['serial-apply'].disabled && b.nodes['serial-result'].disabled);
                        assert.ok(!b.nodes['serial-edit'].hidden && !b.nodes['settings-values'].hidden);
            assert.match(b.nodes['settings-detail'].textContent, /stale/);
            const count = b.calls.length; b.click('serial-save'); await tick(); assert.equal(b.calls.length, count);
            b.queues[path].push(json({id: i + 1, action, state: 'ok'})); b.fire(1000); await tick();
            assert.ok(!b.nodes['serial-apply'].disabled && !b.nodes['serial-edit'].hidden);
            assert.match(b.nodes['serial-operation-detail'].textContent, /completed.*RAM.*NVS/);
        }
        assert.equal(b.sockets.length, 1); assert.ok(!b.sockets[0].closed && !b.sockets[0].sent.length);
    });
    await test('Serial validation and capacity failures never auto-retry or transmit command strings', async () => {
        const b = browser({role: 'admin'}); b.start(); await tick(); b.click('select-settings'); await tick();
        const path = '/api/settings/serial-operation';
        for (const [key, value] of [['baud', '0'], ['baud', '1000001'], ['baud', '1e3'], ['baud', '-1'], ['parity', 'mark'], ['rts_threshold', '128']]) {
            b.click('refresh-settings'); await tick(); b.nodes['edit-' + key].value = value;
            const count = b.calls.length; b.click('serial-apply'); await tick(); assert.equal(b.calls.length, count);
        }
        b.click('refresh-settings'); await tick();
        for (const status of [400, 403, 429, 503]) {
            b.queues[path].push(failure(status)); b.click('serial-save'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, /Check Result/);
            const count = b.calls.length; await tick(); b.click('serial-save'); await tick(); assert.equal(b.calls.length, count);
            assert.ok(!b.nodes['serial-operation-detail'].textContent.includes('SECRET'));
            b.queues[path].push(json({id: 0, action: 'none', state: 'idle'})); b.click('serial-result'); await tick();
            b.click('refresh-settings'); await tick();
        }
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 4);
        b.queues[path].push(json({id: 1, action: 'save', state: 'pending'})); b.click('serial-save'); await tick();
        b.queues[path].push(json({id: 1, action: 'save', state: 'ok'})); b.fire(1000); await tick();
        b.click('refresh-settings'); await tick();
        b.queues[path].push(() => { throw new Error('lost'); }); b.click('serial-reset'); await tick();
        b.queues[path].push(json({id: 1, action: 'save', state: 'ok'})); b.click('serial-result'); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /acknowledgement was lost.*earlier operation/);
        assert.ok(b.sockets.every(s => !s.closed));
    });
    await test('Serial navigation fences delayed acknowledgement without losing sockets, lease or uncertain-work gate', async () => {
        const b = browser({role: 'admin'}); b.start(); await tick(); const serial = b.sockets[0]; serial.emit('open');
        serial.emit('message', {data: JSON.stringify({type: 'hello', clientId: 8, writerId: 8, role: 'writer'})});
        b.click('select-admin'); b.click('admin-toggle'); await tick(); b.sockets[1].emit('open');
        b.click('select-settings'); await tick(); const d = deferred(), path = '/api/settings/serial-operation';
        b.queues[path].push(d.promise); b.click('serial-reset'); await tick();
        const post = b.calls.find(c => c.url === path); b.click('select-serial'); assert.ok(post.signal.aborted);
        d.resolve(json({id: 44, action: 'reset', state: 'pending'})); await tick();
        b.click('select-settings'); await tick(); assert.ok(b.nodes['serial-reset'].disabled);
        b.queues[path].push(json({id: 44, action: 'reset', state: 'ok'})); b.click('serial-result'); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /completed/);
        assert.equal(b.sockets.length, 2); assert.ok(b.sockets.every(s => !s.closed));
        assert.equal(b.nodes['client-id'].textContent, '8'); assert.equal(b.nodes['writer-id'].textContent, '8');
        assert.deepEqual(serial.sent, []);
    });
    await test('Serial result bounds, failure explanations, timeout and no result replay', async () => {
        const b = browser({role: 'admin'}); b.start(); await tick(); b.click('select-settings'); await tick();
        const path = '/api/settings/serial-operation';
        for (const state of ['loaded_defaults', 'failed', 'rollback_failed', 'cancelled', 'pending']) {
            b.queues[path].push(json({id: 42, action: 'reset', state})); b.click('serial-result'); await tick();
            assert.ok(!b.nodes['serial-operation-detail'].textContent.includes('unknown. Check'));
        }
        for (const response of [new Response(' '.repeat(97)), json({id: 0, action: 'save', state: 'ok'}),
            json({id: 42, action: 'save', state: 'ok', extra: 1}), json({id: 42, action: '<img>', state: 'ok'}),
            json({id: -1, action: 'none', state: 'idle'}), new Response(Uint8Array.of(255))]) {
            b.queues[path].push(response); b.click('serial-result'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, /outcome unknown/);
        }
        b.queues[path].push(o => new Promise((_, reject) => o.signal.addEventListener('abort', () => reject(new Error('timeout')))));
        b.click('serial-result'); await tick(); b.fire(15000); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /No automatic retry/);
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 0);
    });
    await test('Serial mutation security: current-session identity, 401 and pagehide cancel work safely', async () => {
        for (const mode of ['identity', '401', 'pagehide']) {
            const b = browser({role: 'admin'}); b.start(); await tick(); b.click('select-settings'); await tick();
            const path = '/api/settings/serial-operation', d = deferred();
            if (mode === 'identity') b.queues['/api/session'].push(session({role: 'admin', username: 'replacement'}));
            else b.queues[path].push(mode === '401' ? failure(401) : d.promise);
            b.click('serial-save'); await tick();
            if (mode === 'identity') { assert.deepEqual(b.redirects, ['/']); assert.equal(b.calls.filter(c => c.url === path).length, 0); }
            if (mode === '401') assert.deepEqual(b.redirects, ['/login']);
            if (mode === 'pagehide') {
                b.emit('pagehide'); const text = b.nodes['serial-operation-detail'].textContent;
                d.resolve(json({id: 42, action: 'save', state: 'pending'})); await tick();
                assert.equal(b.nodes['serial-operation-detail'].textContent, text);
            }
            assert.ok(b.sockets.every(s => s.closed) && b.nodes['serial-settings'].hidden);
        }
    });
    await test('Serial uncertain outcomes survive repeated result reads, refresh and navigation', async () => {
        for (const lostAck of [true, false]) {
            const b = await adminBrowser(), path = '/api/settings/serial-operation';
            b.click('select-settings'); await tick();
            b.queues[path].push(lostAck ? () => { throw new Error('lost'); } : json({id: 41, action: 'save', state: 'pending'}));
            b.click('serial-save'); await tick();
            const warning = lostAck ? /acknowledgement was lost/ : /Previous result was replaced.*unknown/;
            for (let i = 0; i < 2; ++i) {
                b.queues[path].push(json({id: 42, action: 'reset', state: 'ok'}));
                if (!lostAck && i === 0) b.fire(1000); else b.click('serial-result');
                await tick();
                assert.match(b.nodes['serial-operation-detail'].textContent, warning);
            }
            b.queues[path].push(failure(503)); b.click('serial-result'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, warning);
            assert.match(b.nodes['serial-operation-detail'].textContent, /No automatic retry/);
            b.click('refresh-settings'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, warning);
            b.click('select-serial'); b.click('select-settings'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, warning);
            b.queues[path].push(json({id: 42, action: 'reset', state: 'ok'}));
            b.click('serial-result'); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, warning);
            b.click('refresh-settings'); await tick();
            b.queues[path].push(json({id: 43, action: 'save', state: 'pending'}));
            b.click('serial-save'); await tick();
            assert.doesNotMatch(b.nodes['serial-operation-detail'].textContent, warning);
            assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 2);
            assert.equal(b.sockets.length, 2); assert.ok(b.sockets.every(s => !s.closed));
            assert.ok(b.sockets.every(s => !s.sent.length));
        }
    });
    await test('Automatic checks: pending then completion refreshes working config, retains outcome and isolates sockets', async () => {
        const b = await adminBrowser(), path = '/api/settings/serial-operation';
        b.click('select-settings'); await tick();
        const before = b.calls.filter(c => c.url === '/api/settings/serial').length;
        b.queues[path].push(json({id: 50, action: 'apply', state: 'pending'}));
        b.nodes['edit-baud'].value = '460800'; b.click('serial-apply');
        assert.match(b.nodes['serial-operation-detail'].textContent, /Applying/); await tick();
        for (const state of ['pending', 'pending', 'ok']) {
            assert.ok(b.nodes['edit-baud'].disabled && b.nodes['serial-stop'].disabled);
            assert.ok(!b.nodes['settings-values'].hidden && !b.nodes['serial-edit'].hidden);
            b.queues[path].push(json({id: 50, action: 'apply', state}));
            if (state === 'ok') b.queues['/api/settings/serial'].push(json({...serialSettings(), baud: 460800}));
            b.elapse(1000); b.fire(1000); await tick();
        }
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'GET').length, 3);
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 1);
        assert.equal(b.calls.filter(c => c.url === '/api/settings/serial').length, before + 1);
        assert.equal(b.nodes['setting-baud'].textContent, '460800');
        assert.match(b.nodes['serial-operation-detail'].textContent, /completed/);
        assert.doesNotMatch(b.nodes['settings-detail'].textContent, /stale/);
        assert.ok(!b.nodes['edit-baud'].disabled && !b.nodes['serial-apply'].disabled);
        assert.ok(![...b.timers.values()].some(t => t.ms === 1000 || t.ms === 15000));
        assert.equal(b.sockets.length, 2); assert.ok(b.sockets.every(s => !s.closed && !s.sent.length));
    });
    await test('Repeated current Settings selection preserves submission, polling and completion refresh', async () => {
        const b = await adminBrowser(), path = '/api/settings/serial-operation';
        b.click('select-settings'); await tick(); b.nodes['edit-baud'].value = '460800';
        const repeatedSelection = async request => {
            const count = b.calls.length, timers = [...b.timers];
            const view = () => Object.fromEntries(Object.entries(b.nodes).map(([id, node]) =>
                [id, [node.hidden, node.disabled, node.value, node.textContent, node['aria-pressed']]]));
            const before = view();
            for (let i = 0; i < 3; ++i) { b.click('select-settings'); await tick(); }
            assert.equal(b.calls.length, count);
            assert.deepEqual([...b.timers], timers);
            assert.deepEqual(view(), before);
            if (request) assert.ok(!request.signal.aborted);
            assert.ok(!b.nodes['serial-settings'].hidden && !b.nodes['settings-values'].hidden && !b.nodes['serial-edit'].hidden);
        };
        const post = deferred(); b.queues[path].push(post.promise);
        b.click('serial-apply'); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /Applying/);
        await repeatedSelection(b.calls.filter(c => c.url === path).at(-1));
        post.resolve(json({id: 57, action: 'apply', state: 'pending'})); await tick();
        await repeatedSelection();
        const pending = deferred(); b.queues[path].push(pending.promise);
        b.fire(1000); await tick();
        await repeatedSelection(b.calls.filter(c => c.url === path).at(-1));
        pending.resolve(json({id: 57, action: 'apply', state: 'pending'})); await tick();
        await repeatedSelection();
        const refresh = deferred(); b.queues['/api/settings/serial'].push(refresh.promise);
        b.queues[path].push(json({id: 57, action: 'apply', state: 'ok'}));
        b.fire(1000); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /completed/);
        assert.match(b.nodes['settings-detail'].textContent, /Reading.*stale/);
        await repeatedSelection(b.calls.filter(c => c.url === '/api/settings/serial').at(-1));
        refresh.resolve(json({...serialSettings(), baud: 460800})); await tick();
        assert.equal(b.nodes['setting-baud'].textContent, '460800');
        assert.equal(b.nodes['edit-baud'].value, '460800');
        assert.ok(!b.nodes['serial-apply'].disabled);
        assert.match(b.nodes['serial-operation-detail'].textContent, /completed/);
        assert.doesNotMatch(b.nodes['settings-detail'].textContent, /stale/);
        await repeatedSelection();
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 1);
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'GET').length, 2);
        assert.equal(b.calls.filter(c => c.url === '/api/settings/serial').length, 2);
        assert.ok(![...b.timers.values()].some(t => t.ms === 1000 || t.ms === 15000));
        assert.equal(b.sockets.length, 2); assert.ok(b.sockets.every(s => !s.closed && !s.sent.length));
        assert.equal(b.nodes['client-id'].textContent, '8'); assert.equal(b.nodes['writer-id'].textContent, '8');
    });
    await test('Ten automatic GET attempts exhaust budget; manual recovery completes without POST retry', async () => {
        const b = await adminBrowser(), path = '/api/settings/serial-operation';
        b.click('select-settings'); await tick();
        b.queues[path].push(json({id: 51, action: 'save', state: 'pending'})); b.click('serial-save'); await tick();
        for (let i = 0; i < 10; ++i) {
            b.queues[path].push(json({id: 51, action: 'save', state: 'pending'}));
            b.elapse(1000); b.fire(1000); await tick();
        }
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'GET').length, 10);
        assert.ok(![...b.timers.values()].some(t => t.ms === 1000 || t.ms === 15000));
        assert.match(b.nodes['serial-operation-detail'].textContent, /Automatic checking stopped.*uncertain.*Check Result/);
        assert.ok(b.nodes['serial-save'].disabled && !b.nodes['serial-result'].disabled);
        assert.match(b.nodes['settings-detail'].textContent, /stale/);
        b.queues[path].push(json({id: 51, action: 'save', state: 'ok'})); b.click('serial-result'); await tick();
        assert.match(b.nodes['serial-operation-detail'].textContent, /completed/);
        assert.ok(!b.nodes['serial-save'].disabled);
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 1);
    });
    await test('15s overall deadline aborts slow checks and fences late bodies and delayed timers', async () => {
        for (const mode of ['fetch', 'body', 'delayed-timer', 'late-response']) {
            const b = await adminBrowser(), path = '/api/settings/serial-operation';
            b.click('select-settings'); await tick();
            b.queues[path].push(json({id: 52, action: 'stop', state: 'pending'})); b.click('serial-stop'); await tick();
            const d = deferred(); let stream;
            if (mode !== 'delayed-timer') {
                b.queues[path].push(mode === 'body' ? new Response(new ReadableStream({start(c) { stream = c; }})) : d.promise);
                b.elapse(1000); b.fire(1000); await tick(); b.elapse(14000);
                if (mode === 'late-response') { d.resolve(json({id: 52, action: 'stop', state: 'ok'})); await tick(); }
                else b.fire(15000);
                assert.ok(b.calls.filter(c => c.url === path).at(-1).signal.aborted);
            } else { b.elapse(15000); b.fire(1000); }
            await tick();
            const text = b.nodes['serial-operation-detail'].textContent;
            assert.match(text, /Automatic checking stopped/);
            assert.ok(!b.nodes['serial-result'].disabled);
            b.queues[path].push(json({id: 52, action: 'stop', state: 'ok'})); b.click('serial-result'); await tick();
            const recovered = b.nodes['serial-operation-detail'].textContent;
            if (stream) { stream.enqueue(new TextEncoder().encode(JSON.stringify({id: 52, action: 'stop', state: 'failed'}))); stream.close(); }
            else d.resolve(json({id: 52, action: 'stop', state: 'failed'}));
            await tick(); assert.equal(b.nodes['serial-operation-detail'].textContent, recovered);
            assert.match(recovered, /completed/);
            assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 1);
        }
    });
    await test('Known terminal outcomes always refresh; failed refresh preserves visible stale snapshot and outcome', async () => {
        for (const state of ['ok', 'failed', 'rollback_failed', 'cancelled', 'loaded_defaults']) {
            const b = await adminBrowser(), path = '/api/settings/serial-operation';
            b.click('select-settings'); await tick();
            b.queues[path].push(json({id: 53, action: 'reset', state: 'pending'})); b.click('serial-reset'); await tick();
            const d = deferred(); b.queues['/api/settings/serial'].push(d.promise);
            b.queues[path].push(json({id: 53, action: 'reset', state})); b.fire(1000); await tick();
            const outcome = b.nodes['serial-operation-detail'].textContent;
            assert.ok(b.nodes['edit-baud'].disabled && !b.nodes['serial-edit'].hidden && !b.nodes['settings-values'].hidden);
            assert.match(b.nodes['settings-detail'].textContent, /stale/);
            d.resolve(failure(503)); await tick();
            assert.equal(b.nodes['serial-operation-detail'].textContent, outcome);
            assert.equal(b.nodes['setting-baud'].textContent, '230400');
            assert.ok(!b.nodes['serial-edit'].hidden && !b.nodes['settings-values'].hidden && !b.nodes['refresh-settings'].disabled);
            assert.match(b.nodes['settings-detail'].textContent, /stale.*Refresh/);
            b.click('refresh-settings'); await tick();
            assert.equal(b.nodes['serial-operation-detail'].textContent, outcome);
            assert.doesNotMatch(b.nodes['settings-detail'].textContent, /stale/);
        }
    });
    await test('Automatic timers and in-flight checks cancel on navigation, pagehide, logout and identity change', async () => {
        for (const mode of ['navigation', 'pagehide', 'logout', 'identity', 'expiry']) for (const inFlight of [false, true]) {
            const b = await adminBrowser(), path = '/api/settings/serial-operation';
            b.click('select-settings'); await tick();
            b.queues[path].push(json({id: 54, action: 'start', state: 'pending'})); b.click('serial-start'); await tick();
            const callbacks = [...b.timers.values()].filter(t => t.ms === 1000 || t.ms === 15000).map(t => t.fn);
            const d = deferred();
            if (inFlight) { b.queues[path].push(d.promise); b.fire(1000); await tick(); }
            if (mode === 'navigation') b.click('select-serial');
            if (mode === 'pagehide') b.emit('pagehide');
            if (mode === 'expiry') b.window.sakSessionExpired();
            if (mode === 'logout') { b.queues['/api/logout'].push(new Response(null, {status: 204})); b.click('sign-out'); }
            if (mode === 'identity') {
                b.queues['/api/session'].push(session({role: 'admin', username: 'replacement'}));
                b.click('connection-toggle'); b.click('connection-toggle');
            }
            await tick();
            const text = b.nodes['serial-operation-detail'].textContent, count = b.calls.filter(c => c.url === path).length;
            if (inFlight) assert.ok(b.calls.filter(c => c.url === path).at(-1).signal.aborted);
            for (const callback of callbacks) callback();
            d.resolve(json({id: 54, action: 'start', state: 'ok'})); await tick();
            assert.equal(b.nodes['serial-operation-detail'].textContent, text);
            assert.equal(b.calls.filter(c => c.url === path).length, count);
            assert.ok(![...b.timers.values()].some(t => t.ms === 1000 || t.ms === 15000));
            if (mode === 'navigation') { b.click('select-settings'); await tick(); assert.equal(b.calls.filter(c => c.url === path).length, count); }
            if (mode === 'pagehide') { b.emit('pageshow', {persisted: true}); await tick(); assert.equal(b.calls.filter(c => c.url === path).length, count); }
        }
    });
    await test('Automatic read errors stop checking; cancelled completion refresh cannot overwrite a newer view', async () => {
        const path = '/api/settings/serial-operation';
        for (const response of [failure(503), new Response(' '.repeat(97)), () => { throw new Error('network'); }]) {
            const b = await adminBrowser(); b.click('select-settings'); await tick();
            b.queues[path].push(json({id: 55, action: 'save', state: 'pending'}), response);
            b.click('serial-save'); await tick(); b.fire(1000); await tick();
            assert.match(b.nodes['serial-operation-detail'].textContent, /Check Result.*No automatic retry/);
            assert.match(b.nodes['settings-detail'].textContent, /stale/);
            assert.ok(!b.nodes['serial-result'].disabled && b.nodes['serial-save'].disabled);
            assert.ok(![...b.timers.values()].some(t => t.ms === 1000 || t.ms === 15000));
            assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 1);
        }
        const b = await adminBrowser(); b.click('select-settings'); await tick();
        const d = deferred(); b.queues['/api/settings/serial'].push(d.promise);
        b.queues[path].push(json({id: 56, action: 'load', state: 'pending'}), json({id: 56, action: 'load', state: 'ok'}));
        b.click('serial-load'); await tick(); b.fire(1000); await tick();
        const outcome = b.nodes['serial-operation-detail'].textContent;
        const read = b.calls.filter(c => c.url === '/api/settings/serial').at(-1);
        b.click('select-serial'); assert.ok(read.signal.aborted);
        b.click('select-settings'); await tick();
        d.resolve(json({...serialSettings(), baud: 110})); await tick();
        assert.equal(b.nodes['setting-baud'].textContent, '230400');
        assert.equal(b.nodes['serial-operation-detail'].textContent, outcome);
    });
    await test('Routine actions never confirm; Reset cancellation has no request or state change', async () => {
        const b = await adminBrowser(), path = '/api/settings/serial-operation'; b.click('select-settings'); await tick();
        const confirms = []; b.window.confirm = message => { confirms.push(message); return false; };
        for (const [i, action] of ['apply', 'start', 'stop', 'load', 'defaults', 'save'].entries()) {
            b.queues[path].push(json({id: i + 1, action, state: 'pending'}), json({id: i + 1, action, state: 'ok'}));
            b.click('serial-' + action); await tick(); b.fire(1000); await tick();
        }
        assert.deepEqual(confirms, []);
        const count = b.calls.length, text = b.nodes['serial-operation-detail'].textContent;
        b.click('serial-reset'); await tick(); assert.equal(b.calls.length, count);
        assert.equal(b.nodes['serial-operation-detail'].textContent, text);
        assert.equal(confirms.length, 1); assert.match(confirms[0], /overwrites saved NVS configuration/);
        assert.equal(b.calls.filter(c => c.url === path && c.method === 'POST').length, 6);
    });
    console.log(`PASS ${passed} browser behavior groups (production C-rendered JS)`);
})().catch(error => { console.error(error); process.exitCode = 1; });