Function probeEndpoint

src/utils/network-check.ts:84–134

(
  endpoint: string,
  label: string,
  timeoutMs = DEFAULT_TIMEOUT_MS,
)

 * Returns a structured result. Never throws — failures become statuses.
 */
export async function probeEndpoint(
  endpoint: string,
  label: string,
  timeoutMs = DEFAULT_TIMEOUT_MS,
): Promise<ProbeResult> {
  const start = Date.now();
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), timeoutMs);

  try {
    // Try HEAD first (lighter on the server). Many CDNs reject HEAD on some
    // paths, so on 405 fall back to GET.
    let response: Response;
    try {
      response = await proxyFetch(endpoint, { method: 'HEAD', signal: controller.signal, redirect: 'follow' });
      if (response.status === 405) {
        response = await proxyFetch(endpoint, { method: 'GET', signal: controller.signal, redirect: 'follow' });
      }
    } catch (e: any) {
      // Some servers don't speak HEAD at all (close the connection); try GET.
      if (!controller.signal.aborted) {
        response = await proxyFetch(endpoint, { method: 'GET', signal: controller.signal, redirect: 'follow' });
      } else {
        throw e;
      }
    }
    const latencyMs = Date.now() - start;
    return {
      endpoint,
      label,
      status: response.ok || (response.status >= 200 && response.status < 500) ? 'ok' : 'http_error',
      httpCode: response.status,
      latencyMs,
    };
  } catch (e: any) {
    const msg = e?.message ?? String(e);
    const aborted = controller.signal.aborted;
    let status: ProbeStatus = 'unknown_error';
    if (aborted) status = 'timeout';
    else if (/ENOTFOUND|EAI_AGAIN|getaddrinfo/i.test(msg)) status = 'dns_failed';
    else if (/ECONNREFUSED/i.test(msg)) status = 'connection_refused';
    return {
      endpoint,
      label,
      status,
      error: msg,
    };
  } finally {
    clearTimeout(timer);
  }
}

/**
 * Run probes against all public endpoints in parallel.