// Reload boundary: state that must survive a /reload inside one parent
// process. Extension modules re-execute on /reload, so any collaborator whose
// lifetime spans sessions is kept behind a process-global keyed by a stable
// symbol; a fresh module instance revives the same state instead of replacing
// it. Per-load state stays in ordinary module bindings. See CONTEXT.md
// "Supported reload boundary".

/**
 * Retain state across /reload: revive the retained value for this key, or
 * create it once and retain it for every later module instance.
 */
export function retainAcrossReload<T>(
  key: symbol,
  create: () => T,
): T {
  const scope = globalThis as typeof globalThis & { [key: symbol]: unknown };
  const existing = scope[key];
  if (existing !== undefined) return existing as T;
  const created = create();
  scope[key] = created;
  return created;
}