export async function getJSON(url) {
  const r = await fetch(url);
  if (!r.ok) throw new Error((await r.text().catch(() => '')) || r.statusText);
  return r.json();
}

export async function postJSON(url, body) {
  const r = await fetch(url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body ?? {}),
    credentials: 'same-origin', // send/receive the session cookie
  });
  if (!r.ok) {
    let msg = r.statusText;
    try {
      const j = await r.json();
      if (j && j.detail) msg = j.detail;
    } catch {
      /* non-JSON error body */
    }
    throw new Error(msg);
  }
  return r.json();
}