isFastLogin example

    public function validate($password, Constraint $constraint)
    {
        if (!$constraint instanceof Password) {
            return;
        }

        /** @var Form $form */
        $form = $this->context->getRoot();

        if ($this->isFastLogin($form)) {
            return;
        }

        $minLength = (int) $this->config->get('minPassword');

        if (empty($password) || ($minLength && \strlen($password) < $minLength)) {
            $this->addError($this->getSnippet(self::SNIPPET_PASSWORD_LENGTH));
        }

        if ($form->has('passwordConfirmation') && $form->get('passwordConfirmation')->getData() !== $password) {
            $error = new FormError($this->getSnippet(self::SNIPPET_PASSWORD_CONFIRMATION));
            

$customerId = $constraint->getCustomerId();

        if (empty($email)) {
            $this->addError($this->getSnippet(self::SNIPPET_MAIL_FAILURE));
        }

        if (!$this->emailValidator->isValid($email)) {
            $this->addError($this->getSnippet(self::SNIPPET_MAIL_FAILURE));
        }

        if (!$this->isFastLogin($constraint) && $this->isExistingEmail($email, $shop, $customerId)) {
            $this->addError($this->getSnippet(self::SNIPPET_MAIL_DUPLICATE));
        }
    }

    /** * @param string $message */
    private function addError($message)
    {
        $this->context
            ->buildViolation($message)