/**
 * Returns true if the error is a programming bug (TypeError, ReferenceError,
 * SyntaxError). Callers should re-throw these so they propagate to the global
 * error handler rather than being silently swallowed.
 */
export function isProgrammingError(error: unknown): boolean {
  return (
    error instanceof TypeError ||
    error instanceof ReferenceError ||
    error instanceof SyntaxError
  );
}

/**
 * Returns true if the error is an AppView network error (AppView unreachable).
 * Callers should return 503 so the user knows to retry.
 *
 * fetchApi() throws with this prefix for connection-level failures:
 * "AppView network error: ..."
 */
export function isNetworkError(error: unknown): boolean {
  return (
    error instanceof Error &&
    error.message.startsWith("AppView network error:")
  );
}

/**
 * Returns true if the error is an AppView 404 Not Found response.
 * Callers should return a 404 HTML page to the user.
 *
 * fetchApi() throws with this prefix for non-ok HTTP responses:
 * "AppView API error: 404 Not Found"
 */
export function isNotFoundError(error: unknown): boolean {
  return (
    error instanceof Error &&
    error.message.startsWith("AppView API error: 404")
  );
}