function installPollingStallWatchdogHarness(dateNowSequence: readonly number[] = [0, 0]) {

let watchdog: (() => void) | undefined;

let resolveWatchdog: ((fn: () => void) => void) | undefined;

const watchdogReady = new Promise<() => void>((resolve) => {

resolveWatchdog = resolve;

});

const realSetTimeout = globalThis.setTimeout;

const realClearTimeout = globalThis.clearTimeout;

const setIntervalSpy = vi.spyOn(globalThis, "setInterval").mockImplementation((fn, delay) => {

if (delay === POLLING_TEST_WATCHDOG_INTERVAL_MS) {

watchdog = fn as () => void;

resolveWatchdog?.(watchdog);

}

return 1 as unknown as ReturnType<typeof setInterval>;

});

return {

async waitForWatchdog() {

for (let attempt = 0; attempt < 200; attempt += 1) {

if (watchdog) {

break;

}

await Promise.resolve();

await new Promise<void>((resolve) => setImmediate(resolve));

if (watchdog) {

return watchdog;

}

expect(watchdog).toBeTypeOf("function");

return watchdog;

return await new Promise<() => void>((resolve, reject) => {

const timeout = realSetTimeout(() => {

reject(new Error("Timed out waiting for polling watchdog interval registration"));

}, 5_000);

watchdogReady.then(

(fn) => {

realClearTimeout(timeout);

resolve(fn);

},

(error: unknown) => {

realClearTimeout(timeout);

reject(error);

},

);

});

},

setNow(now: number) {

dateNowSpy.mockReset();