text: from django.contrib.auth import get_user_model
  from django.urls import reverse
  from django.test import TestCase
  from rest_framework import status
  from rest_framework.test import APIClient
  from core.models import Tag, Recipe
  from recipe.serializers import TagSerializer
  
  TAGS_URL = reverse('recipe:tag-list')
  
  
  class PublicTagsApiTests(TestCase):
      '''Test the publicly available tags API'''
  
      def setUp(self):
          self.client = APIClient()
  
      def test_login_required(self):
          '''Test that login is required for retrieving tags'''
          res = self.client.get(TAGS_URL)
          self.assertEqual(res.status_code, status.HTTP_401_UNAUTHORIZED)
  
  
  class PrivateTagsApiTests(TestCase):
      '''Test the authorized user tags API'''
  
      def setUp(self):
          self.user = get_user_model().objects.create_user(
              'krzysiu@krzysiu.pl',
              'testpass'
          )
          self.client = APIClient()
          self.client.force_authenticate(self.user)
  
      def test_retrieve_tags(self):
          '''Test retrieving tags'''
          Tag.objects.create(user=self.user, name='Main')
          Tag.objects.create(user=self.user, name='Beef')
  
          res = self.client.get(TAGS_URL)
  
          tags = Tag.objects.all().order_by('-name')
          serializer = TagSerializer(tags, many=True)
  
          self.assertEqual(res.status_code, status.HTTP_200_OK)
          self.assertEqual(res.data, serializer.data)
  
      def test_retrieve_user_tags(self):
          '''Test that tags returned are for authenticated user '''
          user2 = get_user_model().objects.create_user(
              'other@other.pl',
              'testpass'
          )
          Tag.objects.create(user=user2, name='FRUITZ')
          tag = Tag.objects.create(user=self.user, name='VEGETABLEZ')
          res = self.client.get(TAGS_URL)
  
          self.assertEqual(res.status_code, status.HTTP_200_OK)
          self.assertEqual(len(res.data), 1)
          self.assertEqual(res.data[0]['name'], tag.name)
  
      def test_create_tag_successful(self):
          '''Test creating a new tag'''
          payload = {'name': "Test tag"}
          self.client.post(TAGS_URL, payload)
          exists = Tag.objects.filter(user=self.user,
                                      name=payload['name']).exists()
          self.assertTrue(exists)
  
      def test_create_tag_invalid(self):
          '''Test creating a new tag with invalid payload'''
          payload = {'name': " "}
          res = self.client.post(TAGS_URL, payload)
          self.assertEqual(res.status_code, status.HTTP_400_BAD_REQUEST)
  
      def test_retrieve_tags_assigned_to_recipes(self):
          '''Test to retrieve tags assigned to recipes'''
          tag1 = Tag.objects.create(user=self.user, name='breakfast')
          tag2 = Tag.objects.create(user=self.user, name='Lunch')
          recipe = Recipe.objects.create(
              title='Jajcownica z jajem',
              time_minutes=10,
              price=2.30,
              user=self.user,
          )
          recipe.tags.add(tag1)
  
          res = self.client.get(TAGS_URL, {'assigned_only': 1})
  
          serializer1 = TagSerializer(tag1)
          serializer2 = TagSerializer(tag2)
  
          self.assertIn(serializer1.data, res.data)
          self.assertNotIn(serializer2.data, res.data)
  
      def test_retrieve_tags_assigned_unique(self):
          '''Test filtering tags by assigned retrieves unique items'''
          tag = Tag.objects.create(user=self.user, name='sniadanko')
          Tag.objects.create(user=self.user, name='lancz')
          recipe1 = Recipe.objects.create(
              title='nalesnioki',
              time_minutes=15,
              price=5.70,
              user=self.user
          )
          recipe1.tags.add(tag)
          recipe2 = Recipe.objects.create(
              title='owsianka',
              time_minutes=1,
              price=1.50,
              user=self.user
          )
          recipe2.tags.add(tag)
  
          res = self.client.get(TAGS_URL, {'assigned_only': 1})
          self.assertEqual(len(res.data), 1)
  