text: """
  Module for all Form Tests.
  """
  import pytest
  from django.utils.translation import ugettext_lazy as _
  
  from pastry_shop.users.forms import UserCreationForm
  from pastry_shop.users.models import User
  
  pytestmark = pytest.mark.django_db
  
  
  class TestUserCreationForm:
      """
      Test class for all tests related to the UserCreationForm
      """
  
      def test_username_validation_error_msg(self, user: User):
          """
          Tests UserCreation Form's unique validator functions correctly by testing:
              1) A new user with an existing username cannot be added.
              2) Only 1 error is raised by the UserCreation Form
              3) The desired error message is raised
          """
  
          # The user already exists,
          # hence cannot be created.
          form = UserCreationForm(
              {
                  "username": user.username,
                  "password1": user.password,
                  "password2": user.password,
              }
          )
  
          assert not form.is_valid()
          assert len(form.errors) == 1
          assert "username" in form.errors
          assert form.errors["username"][0] == _("This username has already been taken.")
  