path: root/source/util/StressTest.mc

// Author:  cirakg & claude ai
// Summary: Watchdog stress build: the largest code of every 2D symbology, encoded, packed, turned into runs and drawn, at twice the normal steps per event; the PIN and change-queue work at the same margin.
//
// Two versions of this module exist; each build keeps exactly one:
//   * (:no_stress), in every normal build: ON is false.
//   * (:stress), only with stress.jungle (`make watchdog`): the app skips
//     the vault and runs StressTest.Job instead of the list.
// Connect IQ stops code that runs too long in one event ("Watchdog
// Tripped"), but only in the simulator's app runs, never in unit tests. So
// this build runs every 2D encoder, the cache packer and the run finder on
// the biggest inputs the app accepts, with TWO job steps per runner step:
// a pass shows that each step uses at most half of the watchdog budget
// (120,000 bytecodes per event on the 512 KB watches, 240,000 elsewhere,
// where the runner already does two steps per tick). Codes that fit the
// screen are then drawn the way CodeView draws them (RunsPainter: straight
// from the runs, or from a bitmap painted in steps), in one onUpdate.
// Before the last code, VaultCase items measure the vault work after a PIN
// and on the change queue (LockJob, ChangeQueueJob, ManageRun replacing
// 4 KB of contents or a long secret, counting and describing the queue,
// 0.9.0 items) at the same margin.
// docker/scripts/app-diag.sh watchdog reads the DIAG stress lines.

import Toybox.Application;
import Toybox.Graphics;
import Toybox.Lang;
import Toybox.System;
import Toybox.WatchUi;

(:stress)
module StressTest {
    const ON = true;
    // Steps per runner step: the safety margin being tested.
    const MARGIN = 2;
    // The last code's text, which stays on the screen to be decoded.
    const SCREEN_TEXT = "OTPW stress";

    // One item: an encoder for the largest input of its kind, through
    // Codes.DisplayJob (encode, pack, runs) like CodeView, MARGIN steps at a time.
    class Item extends Jobs.Job {
        var name as String;
        var steps as Number = 0;
        var job as Codes.DisplayJob;
        var symbology as Number;
        var painter as RunsPainter? = null;
        // Highest memory use seen between steps.
        var peak as Number = 0;

        function initialize(label as String, type as Number, encoder as Codes.MatrixJob) {
            Job.initialize();
            name = label;
            symbology = type;
            job = new Codes.DisplayJob(encoder, null);
        }

        // The display job, then (when there are runs) the painter.
        function step(budget as Number) as Boolean {
            for (var i = 0; i < MARGIN; i++) {
                steps++;
                var used = System.getSystemStats().usedMemory;
                peak = used > peak ? used : peak;
                var p = painter;
                if (p != null) {
                    if (p.step(budget)) {
                        return true;
                    }
                } else if (job.step(budget)) {
                    var runs = job.runs;
                    if (runs == null) {
                        return true;
                    }
                    painter = new RunsPainter(runs, Codes.minModulePx(symbology));
                }
            }
            return false;
        }
    }

    // A RAM store for the vault cases. Values are kept as they are, without
    // the copies Application.Storage (or the tests' MemoryBackend) makes, so
    // the store adds no VM loops to what is measured, and two full vaults
    // fit without the storage limits.
    class RamBackend extends Persist.Backend {
        var values as Dictionary<String, Application.Storage.ValueType> = {} as Dictionary<String, Application.Storage.ValueType>;

        function initialize() {
            Backend.initialize();
        }

        function getValue(key as String) as Application.Storage.ValueType {
            return values[key] as Application.Storage.ValueType;
        }

        function setValue(key as String, value as Application.Storage.ValueType) as Void {
            values[key] = value;
        }

        function deleteValue(key as String) as Void {
            values.remove(key);
        }
    }

    // One case of vault work after a PIN or on a queue change. Setup builds
    // the vaults in small steps (one entry, queue item or KDF step each).
    // The measured run then does the work at MARGIN: what runs in one event
    // runs twice in it, and jobs run on two identical vaults (A and B), one
    // step of each per step of this job, in stages (one job per vault each).
    //   * UNLOCK: each vault has a PIN, LOCKS unlocked entries with a queued
    //     "Require PIN" each, `pending` pending locked entries and a locked
    //     session. B's unlock derivation finishes during setup; A's runs in
    //     the measured run. Its last step finishes both unlocks, as
    //     PinView.onUnlockDone does; then the LockJobs run.
    //   * COUNT / DESCRIBE: one locked vault. COUNT's queue holds a REPLACE
    //     of a locked code with `material` bytes of checked contents and
    //     LOCKS - 1 LOCKs, and the work is ChangeQueue.changed() +
    //     countToConfirm(). DESCRIBE's holds LOCKS edits with names of the
    //     largest size, and the work is DescribeJob (QueueMenu), stepped on
    //     the one vault MARGIN times per step.
    //   * REPLACE_QUEUED: a locked code entry, a REPLACE with `material`
    //     digits queued by ManageRun (as the settings queue it) during
    //     setup; the measured run applies it with ChangeQueueJob.
    //   * REPLACE_DIRECT: an unlocked code entry, and the same REPLACE
    //     applied at once (ManageRun, not confirmed, as SettingsJob runs it).
    //   * LEGACY: a locked code entry and a 0.9.0 queue item (a bare box,
    //     aad "OTPW-Q-1") replacing it with `material` raw digits; locked,
    //     with both unlock derivations done in setup. Stages: DescribeJob
    //     (the menu), the unlock and LockJob, ChangeQueueJob ("Confirm all"
    //     with the menu's keys).
    //   * SECRET: a locked OTP entry, and a REPLACE with a valid Base32
    //     secret padded with spaces to ManageRun.MAX_SECRET_TEXT characters:
    //     queued (ManageRun), then confirmed (ChangeQueueJob).
    //   * SPACES: an unlocked code entry and a REPLACE of `material` spaces
    //     (refused: "Contents: missing").
    class VaultCase extends Jobs.Job {
        static const UNLOCK = 0;
        static const COUNT = 1;
        static const DESCRIBE = 2;
        static const REPLACE_QUEUED = 3;
        static const REPLACE_DIRECT = 4;
        static const LEGACY = 5;
        static const SECRET = 6;
        static const SPACES = 7;
        // Unlocked entries, one queued item each (ChangeQueue.MAX_ITEMS).
        static const LOCKS = 16;
        static const PIN = "1234";

        var name as String;
        var kind as Number;
        var pending as Number;
        var material as Number;
        // False during setup, true in the measured run.
        var measuring as Boolean = false;
        var steps as Number = 0;
        var measured as Number = 0;
        var peak as Number = 0;
        var result as String = "";

        private var _vaults as Array<Vault> = [] as Array<Vault>;
        private var _pins as Array<PinJob> = [] as Array<PinJob>;
        private var _targets as Array<String> = [] as Array<String>;
        private var _phase as Number = 0;
        private var _n as Number = 0;
        private var _job as PinJob? = null;
        private var _setupRun as ManageRun? = null;
        // The measured stage, its jobs (one per vault) and which are done.
        private var _stage as Number = -1;
        private var _jobs as Array<Jobs.Job> = [] as Array<Jobs.Job>;
        private var _done as Array<Boolean> = [] as Array<Boolean>;
        // LEGACY: the keys each vault's menu read.
        private var _keys as Array<Array<String>> = [] as Array<Array<String>>;

        function initialize(label as String, type as Number, pendingCount as Number, materialBytes as Number) {
            Job.initialize();
            name = label;
            kind = type;
            pending = pendingCount;
            material = materialBytes;
        }

        function step(budget as Number) as Boolean {
            var used = System.getSystemStats().usedMemory;
            peak = used > peak ? used : peak;
            if (measuring) {
                measured++;
                return measure(budget);
            }
            steps++;
            return setup(budget);
        }

        private function vaultCount() as Number {
            return kind == COUNT || kind == DESCRIBE ? 1 : 2;
        }

        // Entries per vault.
        private function entryCount() as Number {
            return kind >= REPLACE_QUEUED ? 1 : LOCKS;
        }

        // One bounded setup step; true when every vault is ready.
        private function setup(budget as Number) as Boolean {
            var v = _vaults.size() > 0 ? _vaults[_vaults.size() - 1] : null;
            if (_phase == 0) {
                v = new Vault(new RamBackend(), new TimeSource());
                _vaults.add(v);
                _targets = [] as Array<String>;
                _job = v.beginSetPin(Bytes.fromUtf8(PIN), Kdf.MIN_ITERATIONS);
                _phase = 1;
            } else if (_phase == 1) {
                if ((_job as PinJob).step(budget)) {
                    (v as Vault).finishSetPin(_job as PinJob);
                    _job = null;
                    _phase = 2;
                    _n = 0;
                }
            } else if (_phase == 2) {
                _targets.add((v as Vault).add(newEntry()));
                _n++;
                if (_n == entryCount()) {
                    if (kind <= DESCRIBE || kind == LEGACY) {
                        (v as Vault).lock();
                    }
                    _phase = 3;
                    _n = 0;
                }
            } else if (_phase == 3) {
                // Locked entries added while locked wait under "p." (pending).
                if (_n < pending) {
                    (v as Vault).add(Fixtures.otp("Pending " + _n, "acct", "Stress", Entry.OTP_TOTP, Hashes.SHA1, 6, 30,
                        "12345678901234567890", true));
                    _n++;
                } else {
                    _phase = 4;
                    _n = 0;
                }
            } else if (_phase == 4) {
                if (queueStep(v as Vault)) {
                    if (kind != UNLOCK && kind != LEGACY) {
                        _phase = 0;
                        return _vaults.size() == vaultCount();
                    }
                    _pins.add((v as Vault).beginUnlock(Bytes.fromUtf8(PIN)));
                    // UNLOCK: the last vault (A) is unlocked in the measured run.
                    if (kind == UNLOCK && _vaults.size() == vaultCount()) {
                        return true;
                    }
                    _phase = 5;
                }
            } else if (_pins[_pins.size() - 1].step(budget)) {
                _phase = 0;
                return _vaults.size() == vaultCount();
            }
            return false;
        }

        private function newEntry() as Entry {
            if (kind == SECRET) {
                return Fixtures.otp("Bank", "acct", "Stress", Entry.OTP_TOTP, Hashes.SHA1, 6, 30, "12345678901234567890", true);
            }
            if (kind >= REPLACE_QUEUED || (kind != UNLOCK && _n == 0)) {
                // The code a REPLACE targets; locked unless replaced directly.
                var e = Fixtures.code("Card", Codes.QR, "1234567890");
                e.locked = kind != REPLACE_DIRECT && kind != SPACES;
                return e;
            }
            return Fixtures.otp("Stress " + _n, "acct", "Stress", Entry.OTP_TOTP, Hashes.SHA1, 6, 30, "12345678901234567890", false);
        }

        // The REPLACE of the replace cases, as ManageForm.read gives it.
        private function replaceAction(v as Vault) as ManageAction {
            var a = new ManageAction();
            a.id = _targets[0];
            a.action = ManageAction.REPLACE;
            if (kind == SECRET) {
                // 200 Base32 characters (125 bytes) in groups, spaces around.
                var group = repeat(" ", 16) + "AAAA";
                var groups = 200 / 4;
                a.text = repeat(" ", ManageRun.MAX_SECRET_TEXT - groups * group.length()) + repeat(group, groups);
            } else if (kind == SPACES) {
                a.text = repeat(" ", material);
            } else {
                a.text = repeat("0123456789", (material + 9) / 10).substring(0, material) as String;
            }
            return a;
        }

        // One step of queueing; true when the vault's queue is complete.
        private function queueStep(v as Vault) as Boolean {
            if (kind == REPLACE_DIRECT || kind == SECRET || kind == SPACES) {
                return true;
            }
            if (kind == LEGACY) {
                // As 0.9.0 queued it: raw contents inside one box.
                var old = new ManageAction();
                old.id = _targets[0];
                old.action = ManageAction.REPLACE;
                old.label = "Card";
                old.material = Bytes.fromUtf8(replaceAction(v).text as String);
                var stored = ChangeQueue.items(v);
                stored.add(SealedBox.sealKeep(v.keyManager.deviceKeys(), Bytes.fromUtf8(ChangeQueue.AAD_V1), old.toBytes(),
                    [] as Array<ByteArray>)); // setup: nothing to wipe
                v.storage().setValue(ChangeQueue.KEY, stored);
                ChangeQueue.changed();
                return true;
            }
            if (kind == REPLACE_QUEUED) {
                var run = _setupRun;
                if (run == null) {
                    _setupRun = new ManageRun(v, replaceAction(v), false);
                    return false;
                }
                if (!run.step(1)) {
                    return false;
                }
                _setupRun = null;
                if (!run.queued) {
                    result = " setup_problem=" + run.message;
                }
                return true;
            }
            var a = new ManageAction();
            a.id = _targets[_n];
            a.label = "Stress " + _n;
            a.action = ManageAction.LOCK;
            if (kind == DESCRIBE) {
                a.action = ManageAction.EDIT;
                a.name = repeat("N", Entry.MAX_NAME_BYTES);
                a.account = repeat("A", Entry.MAX_NAME_BYTES);
                a.group = repeat("G", Entry.MAX_GROUP_BYTES);
                a.label = Forms.label(a.name, a.account);
            } else if (kind == COUNT && _n == 0) {
                // Checked contents, as ManageRun queues them.
                a.action = ManageAction.REPLACE;
                a.material = Bytes.fromUtf8(repeat("abcdefghij", (material + 9) / 10).substring(0, material) as String);
                a.decoded = true;
            }
            ChangeQueue.add(v, a);
            _n++;
            return _n == LOCKS;
        }

        // The measured run.
        private function measure(budget as Number) as Boolean {
            if (kind == COUNT) {
                for (var i = 0; i < MARGIN; i++) {
                    ChangeQueue.changed();
                    result = " to_confirm=" + ChangeQueue.countToConfirm(_vaults[0]);
                }
                return true;
            }
            if (_stage < 0) {
                if (kind == UNLOCK) {
                    // A's derivation; its last step finishes both unlocks.
                    if (!_pins[_vaults.size() - 1].step(budget)) {
                        return false;
                    }
                    Diag.data("stress", "kdf_done name=" + name);
                }
                return nextStage();
            }
            var all = true;
            for (var i = 0; i < _jobs.size(); i++) {
                if (!_done[i]) {
                    _done[i] = _jobs[i].step(1);
                    all = all && _done[i];
                }
            }
            if (!all) {
                return false;
            }
            summary();
            return nextStage();
        }

        // Start the next stage's jobs (A first); true when there is none.
        private function nextStage() as Boolean {
            _stage++;
            var stages = kind == LEGACY ? 3 : (kind == SECRET ? 2 : 1);
            if (_stage >= stages) {
                return true;
            }
            var previous = _jobs;
            _jobs = [] as Array<Jobs.Job>;
            _done = [] as Array<Boolean>;
            var last = _vaults.size() - 1;
            for (var i = last; i >= 0; i--) {
                var v = _vaults[i];
                var job = new Jobs.Job(); // replaced below
                if (kind == DESCRIBE) {
                    _jobs.add(new DescribeJob(v));
                    _done.add(false);
                    job = new DescribeJob(v);
                } else if (kind == UNLOCK) {
                    result += " v" + i + "_unlocked=" + v.finishUnlock(_pins[i]);
                    job = new LockJob(v, true);
                } else if (kind == REPLACE_QUEUED || (kind == SECRET && _stage == 1)) {
                    job = new ChangeQueueJob(v, null);
                } else if (kind == LEGACY) {
                    if (_stage == 0) {
                        job = new DescribeJob(v);
                    } else if (_stage == 1) {
                        _keys.add((previous[last - i] as DescribeJob).keys);
                        result += " v" + i + "_unlocked=" + v.finishUnlock(_pins[i]);
                        job = new LockJob(v, true);
                    } else {
                        job = new ChangeQueueJob(v, _keys[last - i]);
                    }
                } else {
                    job = new ManageRun(v, replaceAction(v), false);
                }
                _jobs.add(job as Jobs.Job);
                _done.add(false);
            }
            return false;
        }

        private function summary() as Void {
            var job = _jobs[0];
            var v = _vaults[_vaults.size() - 1];
            result += " [" + _stage + "]";
            if (job instanceof LockJob) {
                ChangeQueue.takeLockLines(); // as the PIN screen does when it closes
                result += " lock_lines=" + job.lines.size() + " pending_left=" + v.pendingIds().size() + " ids=" + v.ids().size()
                    + " queue_left=" + ChangeQueue.count(v);
            } else if (job instanceof ChangeQueueJob) {
                result += " lines=" + job.lines.size() + " first='" + job.lines[0] + "' queue_left=" + ChangeQueue.count(v);
            } else if (job instanceof DescribeJob) {
                result += " described=" + job.lines.size();
            } else if (job instanceof ManageRun) {
                result += " failed=" + job.failed + " queued=" + job.queued + " message='" + job.message + "'";
            }
        }
    }

    // The screen: progress while encoding, the runs once an item is done.
    class StressView extends WatchUi.View {
        var title as String = "Stress test";
        var painter as RunsPainter? = null;
        private var _first as Boolean = true;

        function initialize() {
            View.initialize();
        }

        function onUpdate(dc as Graphics.Dc) as Void {
            dc.setColor(Graphics.COLOR_BLACK, Graphics.COLOR_WHITE);
            dc.clear();
            var p = painter;
            if (p != null) {
                var drawn = p.draw(dc);
                Diag.data("stress", "drawn name=" + title + " runs=" + p.runs.runs.size() + " direct=" + p.direct()
                    + " drawn=" + drawn);
                painter = null;
            } else {
                dc.drawText(dc.getWidth() / 2, dc.getHeight() / 2, Graphics.FONT_XTINY, title, Graphics.TEXT_JUSTIFY_CENTER);
            }
            if (_first) {
                _first = false;
                Diag.firstFrame();
                start();
            }
        }
    }

    var view as StressView? = null;
    var items as Array<Item or VaultCase> = [] as Array<Item or VaultCase>;
    var current as Item? = null;
    var currentCase as VaultCase? = null;
    var runner as Jobs.JobRunner? = null;

    function initialView() as [WatchUi.Views] or [WatchUi.Views, WatchUi.InputDelegates] {
        var v = new StressView();
        view = v;
        return [v];
    }

    // The largest inputs: QR version 40 (bytes) and a long digit string at
    // level H, Data Matrix 144 x 144 (ASCII) and Base256, Aztec 32 layers
    // (text and binary), PDF417 as big as this screen takes; then the
    // largest Data Matrix and QR that fit the screen, to be drawn (on most
    // watches the QR is drawn from a bitmap, RunsPainter's other path).
    function start() as Void {
        var letters = repeat("abcdefghij", 290);
        var digits = repeat("0123456789", 80);
        var binary = repeat("é€", 120);
        var screen = System.getDeviceSettings();
        var w = screen.screenWidth;
        var h = screen.screenHeight;
        var round = screen.screenShape == System.SCREEN_SHAPE_ROUND;
        items = [
            new Item("qr_v40", Codes.QR, new Qr.QrJob(letters, 0, 0, -1)),
            new Item("qr_digits_h", Codes.QR, new Qr.QrJob(digits, 3, 0, -1)),
            new Item("dm_144", Codes.DATAMATRIX, new DataMatrix.DataMatrixJob(letters.substring(0, 1500) as String)),
            new Item("dm_base256", Codes.DATAMATRIX, new DataMatrix.DataMatrixJob(binary)),
            new Item("aztec_text", Codes.AZTEC, new Aztec.AztecJob(letters.substring(0, 1400) as String, 0)),
            new Item("aztec_binary", Codes.AZTEC, new Aztec.AztecJob(binary.substring(0, 160) as String, 3)),
            new Item("pdf417_text", Codes.PDF417, new Pdf417.Pdf417Job(letters.substring(0, w > 300 ? 900 : 250) as String,
                1, w, h, round)),
            new Item("pdf417_digits", Codes.PDF417, new Pdf417.Pdf417Job(digits.substring(0, 400) as String, 1, w, h, round)),
            new Item("dm_fit", Codes.DATAMATRIX, new DataMatrix.DataMatrixJob(letters.substring(0, largestDataMatrix(w, h, round))
                as String)),
            // Single-event vault work (VaultCase).
            new VaultCase("queue_count_big", VaultCase.COUNT, 0, Entry.MAX_PAYLOAD_BYTES),
            new VaultCase("queue_describe", VaultCase.DESCRIBE, 0, 0),
            new VaultCase("unlock_locks", VaultCase.UNLOCK, 0, 0),
            new VaultCase("unlock_pending", VaultCase.UNLOCK, Vault.MAX_ENTRIES - VaultCase.LOCKS, 0),
            new VaultCase("replace_code_4k", VaultCase.REPLACE_QUEUED, 0, Entry.MAX_PAYLOAD_BYTES),
            new VaultCase("replace_code_4k_direct", VaultCase.REPLACE_DIRECT, 0, Entry.MAX_PAYLOAD_BYTES),
            new VaultCase("queue_legacy_4k", VaultCase.LEGACY, 0, Entry.MAX_PAYLOAD_BYTES),
            new VaultCase("replace_secret_1k", VaultCase.SECRET, 0, 0),
            new VaultCase("replace_spaces_4k", VaultCase.SPACES, 0, Entry.MAX_PAYLOAD_BYTES),
            // Last, so it stays on the screen: app-diag.sh decodes it.
            new Item("qr_fit", Codes.QR, new Qr.QrJob(SCREEN_TEXT, 1, largestQrVersion(w, h, round), -1))
        ] as Array<Item or VaultCase>;
        Diag.data("stress", "start used_kb=" + System.getSystemStats().usedMemory / 1024);
        next();
    }

    function next() as Void {
        if (items.size() == 0) {
            Diag.data("stress", "all done");
            return;
        }
        var item = items[0];
        items = items.slice(1, null) as Array<Item or VaultCase>;
        if (item instanceof VaultCase) {
            currentCase = item;
            (view as StressView).title = item.name;
            WatchUi.requestUpdate();
            var r = new Jobs.JobRunner(item, Kdf.ITERATIONS_PER_STEP, new Lang.Method(StressTest, :onCaseReady));
            runner = r;
            r.start();
            return;
        }
        current = item;
        (view as StressView).title = item.name;
        WatchUi.requestUpdate();
        var r = new Jobs.JobRunner(item, 1, new Lang.Method(StressTest, :onItemDone));
        runner = r;
        r.start();
    }

    function onItemDone() as Void {
        var item = current as Item;
        var runs = item.job.runs;
        Diag.data("stress", "done name=" + item.name + " steps=" + item.steps + " peak_kb=" + item.peak / 1024
            + " total_kb=" + System.getSystemStats().totalMemory / 1024 + " error=" + item.job.error
            + " size=" + (runs != null ? runs.width + "x" + runs.height : "-"));
        (view as StressView).painter = item.painter;
        WatchUi.requestUpdate();
        // The next item starts in its own event, after the draw.
        var r = new Jobs.JobRunner(new Jobs.Job(), 1, new Lang.Method(StressTest, :next));
        runner = r;
        r.start();
    }

    // Setup done: the measured run starts with a fresh runner, so its first
    // event holds no setup step.
    function onCaseReady() as Void {
        var c = currentCase as VaultCase;
        c.measuring = true;
        Diag.data("stress", "start name=" + c.name + " setup_steps=" + c.steps + " used_kb=" + System.getSystemStats().usedMemory / 1024);
        var r = new Jobs.JobRunner(c, Kdf.ITERATIONS_PER_STEP, new Lang.Method(StressTest, :onCaseDone));
        runner = r;
        r.start();
    }

    function onCaseDone() as Void {
        var c = currentCase as VaultCase;
        Diag.data("stress", "done name=" + c.name + " setup_steps=" + c.steps + " measured_steps=" + c.measured + " peak_kb=" + c.peak / 1024
            + " total_kb=" + System.getSystemStats().totalMemory / 1024 + c.result);
        currentCase = null;
        var r = new Jobs.JobRunner(new Jobs.Job(), 1, new Lang.Method(StressTest, :next));
        runner = r;
        r.start();
    }

    function repeat(text as String, times as Number) as String {
        var out = "";
        for (var i = 0; i < times; i++) {
            out += text;
        }
        return out;
    }

    // The largest QR version that fits this screen at 2 px per module.
    function largestQrVersion(w as Number, h as Number, round as Boolean) as Number {
        for (var v = 40; v > 1; v--) {
            var total = 17 + 4 * v + 8;
            if (Codes.fits(total, total, 2, w, h, round)) {
                return v;
            }
        }
        return 1;
    }

    // An ASCII payload length that fills the largest Data Matrix fitting
    // this screen at 2 px per module.
    function largestDataMatrix(w as Number, h as Number, round as Boolean) as Number {
        var best = 1;
        for (var i = 0; i < DataMatrix.SIZES.size(); i++) {
            var s = DataMatrix.SIZES[i] as Array<Number>;
            if (Codes.fits(s[0] + 2, s[0] + 2, 2, w, h, round)) {
                best = s[3];
            }
        }
        return best;
    }
}

(:no_stress)
module StressTest {
    const ON = false;

    function initialView() as [WatchUi.Views] or [WatchUi.Views, WatchUi.InputDelegates] {
        return [new WatchUi.View()];
    }
}