import cbor from 'cbor';

export function decodeCborFirst(input: string | Buffer | ArrayBufferView): any {
  try {
    // throws if there are extra bytes
    return cbor.decodeFirstSync(input);
  } catch (err) {
    const _err = err as CborDecoderError;
    // if the error was due to extra bytes, return the unpacked value
    if (_err.value) {
      return _err.value;
    }
    throw err;
  }
}

/**
 * Intuited from a quick scan of `cbor.decodeFirstSync()` here:
 *
 * https://github.com/hildjj/node-cbor/blob/v5.1.0/lib/decoder.js#L189
 */
class CborDecoderError extends Error {
  value: any;
}