onTapResetPassword method Null safety

Implementation

void onTapResetPassword(BuildContext context) async {
  final String username = usernameController.text.trim();
  final String newPassword = newPasswordController.text.trim();
  final String confirmationCode = confirmationCodeController.text.trim();
  if (username.isEmpty) {
    EventService().eventBus.fire(PopupEvent(
        type: PopupType.alert,
        action: PopupAction.show,
        data: {"title": "오류", "content": "아이디를 입력하세요."},
        onClose: () {
          Navigator.of(context, rootNavigator: true).popUntil((route) => !route.settings.name!.startsWith(PopupScreen.routeName));
        }));
    return;
  }

  try {
    await Amplify.Auth.confirmResetPassword(username: username, newPassword: newPassword, confirmationCode: confirmationCode);
    EventService().eventBus.fire(PopupEvent(
        type: PopupType.alert,
        action: PopupAction.show,
        data: {"title": "성공", "content": "비밀번호 재설정에 성공했습니다."},
        onClose: () {
          Navigator.of(context, rootNavigator: true).popUntil((route) => route.settings.name == SplashScreen.routeName);
          Navigator.of(context, rootNavigator: true).pushNamed(SignInScreen.routeName);
        }));
  } on AuthException catch (e) {
    EventService().eventBus.fire(PopupEvent(
        type: PopupType.alert,
        action: PopupAction.show,
        data: {"title": "오류", "content": e.message},
        onClose: () {
          Navigator.of(context, rootNavigator: true).popUntil((route) => !route.settings.name!.startsWith(PopupScreen.routeName));
        }));
  }
}