Spaces:
Sleeping
Sleeping
File size: 1,479 Bytes
cd99321 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | const PROBE_INTERVAL_MS = 30_000
const PROBE_TIMEOUT_MS = 1_500
let reachable = true
const listeners = new Set<(v: boolean) => void>()
function setReachable(v: boolean): void {
if (reachable === v) return
reachable = v
listeners.forEach(fn => fn(v))
}
async function probe(): Promise<void> {
if (!navigator.onLine) { setReachable(false); return }
try {
const ctrl = new AbortController()
const t = setTimeout(() => ctrl.abort(), PROBE_TIMEOUT_MS)
const res = await fetch('/api/health', {
method: 'GET',
credentials: 'include',
cache: 'no-store',
signal: ctrl.signal,
})
clearTimeout(t)
// /api/health returns JSON. CF Access / Pangolin will either return HTML
// (Pangolin 200 auth wall) or trigger a cross-origin redirect that throws
// below. Both proxy-auth scenarios resolve to reachable = false.
const ct = res.headers.get('content-type') || ''
setReachable(res.ok && ct.includes('application/json'))
} catch {
setReachable(false)
}
}
export function startConnectivityProbe(): void {
probe()
setInterval(probe, PROBE_INTERVAL_MS)
window.addEventListener('online', probe)
window.addEventListener('offline', () => setReachable(false))
}
export function isReachable(): boolean { return reachable }
export function probeNow(): Promise<void> { return probe() }
export function onChange(fn: (v: boolean) => void): () => void {
listeners.add(fn)
return () => listeners.delete(fn)
}
|