/**
 * Length cap for extracted messages. Aligned with the core scrubber's
 * MAX_STRING_LENGTH so an error-reporting site never retains (dedup keys) or
 * forwards more than the telemetry layer would keep anyway.
 */
const MAX_SAFE_ERROR_MESSAGE_LENGTH = 500

/**
 * Extract a bounded message from any thrown value without ever throwing.
 * Error-reporting sites run inside catch blocks and third-party emitters,
 * where a poisoned `message` getter or a throwing `toString()` would replace
 * the real failure with its own — and an unbounded message retained as a
 * dedup key is a memory footgun. (`uwc-bridge-child` keeps a local copy —
 * that package stays dependency-free; keep the two in sync.)
 */
export function safeErrorMessage(error: unknown): string {
  try {
    const message = error instanceof Error ? error.message : String(error)
    return message.length > MAX_SAFE_ERROR_MESSAGE_LENGTH
      ? message.slice(0, MAX_SAFE_ERROR_MESSAGE_LENGTH)
      : message
  } catch {
    return 'Unreadable error object'
  }
}