text: from django.contrib.auth.models import User
  from django.test import TestCase
  from rest_framework import serializers
  
  from api.models import Review
  from api.serializers import ReviewSerializer
  
  
  class ReviewSerializerTests(TestCase):
      def setUp(self):
          self.user = User.objects.create_user(
              'user1',
              'user1@example.com',
              'user1_pwd'
          )
  
          self.review = Review(
              title='My review',
              summary='This is my first review.',
              rating=1,
              ip_address='127.0.0.1',
              company='Some Company',
              reviewer='Some Reviewer',
              user=self.user,
          )
  
          self.data = {
              'id': 1,
              'title': 'My review',
              'summary': 'This is my first review.',
              'rating': 1,
              'ip_address': '127.0.0.1',
              'company': 'Some Company',
              'reviewer': 'Some Reviewer',
          }
  
      def test_serialize_model(self):
          self.review.save()
          serializer = ReviewSerializer(self.review)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
  
          data = serializer.data
  
          self.assertIsNotNone(data.get('id'))
          self.assertEqual(data.get('title'), 'My review')
          self.assertEqual(data.get('summary'), 'This is my first review.')
          self.assertEqual(data.get('rating'), 1)
          self.assertFalse('ip_address' in data)
          self.assertEqual(data.get('company'), 'Some Company')
          self.assertEqual(data.get('reviewer'), 'Some Reviewer')
          self.assertEqual(data.get('user'), 'user1')
  
      def test_deserialize_data(self):
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertTrue(serializer.is_valid())
  
          validated_data = serializer.validated_data
  
          self.assertEqual(validated_data.get('title'), 'My review')
          self.assertEqual(validated_data.get('summary'), 'This is my first review.')
          self.assertEqual(validated_data.get('rating'), 1)
          self.assertEqual(validated_data.get('ip_address'), '127.0.0.1')
          self.assertEqual(validated_data.get('company'), 'Some Company')
          self.assertEqual(validated_data.get('reviewer'), 'Some Reviewer')
  
      def test_validate_long_title(self):
          self.data['title'] = 'This is a very very very very very very very very very long title'
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertFalse(serializer.is_valid())
          self.assertEqual(len(serializer.errors.get('title')), 1)
  
      def test_validate_long_summary(self):
          self.data['summary'] = ''.join(['a' for i in range(10001)])
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertFalse(serializer.is_valid())
          self.assertEqual(len(serializer.errors.get('summary')), 1)
  
      def test_validate_below_zero_rating(self):
          self.data['rating'] = -1
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertFalse(serializer.is_valid())
          self.assertEqual(len(serializer.errors.get('rating')), 1)
  
      def test_validate_beyond_five_rating(self):
          self.data['rating'] = 6
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertFalse(serializer.is_valid())
          self.assertEqual(len(serializer.errors.get('rating')), 1)
  
      def test_validate_invalid_ip_address(self):
          self.data['ip_address'] = '127,0,0,1'
          serializer = ReviewSerializer(data=self.data)
  
          self.assertIsInstance(serializer, serializers.ModelSerializer)
          self.assertFalse(serializer.is_valid())
          self.assertEqual(len(serializer.errors.get('ip_address')), 1)
  