Password

password.dart

class Password {
  Password(String password)
      : assert(password.length > 8),
        _password = password;

  String _password;

  set value(String newPassword) {
    if (_isTooShort(newPassword)) {
      throw Exception('Too short!!!');
    } else if (!_hasNumbersLetters(newPassword)) {
      throw Exception('You must have numbers '
          'AND letters!!!');
    } else {
      _password = newPassword;
    }
  }

  bool _isTooShort(String password) {
    return password.length <= 8;
  }

  bool _hasNumbersLetters(String password) {
    return _hasNumbers(password) && _hasLetters(password);
  }

  bool _hasNumbers(String password) {
    return true;
  }

  bool _hasLetters(String password) {
    return true;
  }

  @override
  String toString() {
    final length = _password.length;
    final stars = '*' * length;
    return 'Password is $stars';
  }
}