django-rest-framework/rest_framework/tests/test_serializer.py

# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import models
from django.db.models.fields import BLANK_CHOICE_DASH
from django.test import TestCase
from django.utils.datastructures import MultiValueDict
from django.utils.translation import ugettext_lazy as _
from rest_framework import serializers, fields, relations
from rest_framework.tests.models import (HasPositiveIntegerAsChoice, Album, ActionItem, Anchor, BasicModel,
    BlankFieldModel, BlogPost, BlogPostComment, Book, CallableDefaultValueModel, DefaultValueModel,
    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo, RESTFrameworkModel)
from rest_framework.tests.models import BasicModelSerializer
import datetime
import pickle


class SubComment(object):
    def __init__(self, sub_comment):
        self.sub_comment = sub_comment


class Comment(object):
    def __init__(self, email, content, created):
        self.email = email
        self.content = content
        self.created = created or datetime.datetime.now()

    def __eq__(self, other):
        return all([getattr(self, attr) == getattr(other, attr)
                    for attr in ('email', 'content', 'created')])

    def get_sub_comment(self):
        sub_comment = SubComment('And Merry Christmas!')
        return sub_comment


class CommentSerializer(serializers.Serializer):
    email = serializers.EmailField()
    content = serializers.CharField(max_length=1000)
    created = serializers.DateTimeField()
    sub_comment = serializers.Field(source='get_sub_comment.sub_comment')

    def restore_object(self, data, instance=None):
        if instance is None:
            return Comment(**data)
        for key, val in data.items():
            setattr(instance, key, val)
        return instance


class NamesSerializer(serializers.Serializer):
    first = serializers.CharField()
    last = serializers.CharField(required=False, default='')
    initials = serializers.CharField(required=False, default='')


class PersonIdentifierSerializer(serializers.Serializer):
    ssn = serializers.CharField()
    names = NamesSerializer(source='names', required=False)


class BookSerializer(serializers.ModelSerializer):
    isbn = serializers.RegexField(regex=r'^[0-9]{13}$', error_messages={'invalid': 'isbn has to be exact 13 numbers'})

    class Meta:
        model = Book


class ActionItemSerializer(serializers.ModelSerializer):

    class Meta:
        model = ActionItem


class ActionItemSerializerCustomRestore(serializers.ModelSerializer):

    class Meta:
        model = ActionItem

    def restore_object(self, data, instance=None):
        if instance is None:
            return ActionItem(**data)
        for key, val in data.items():
            setattr(instance, key, val)
        return instance


class PersonSerializer(serializers.ModelSerializer):
    info = serializers.Field(source='info')

    class Meta:
        model = Person
        fields = ('name', 'age', 'info')
        read_only_fields = ('age',)


class NestedSerializer(serializers.Serializer):
    info = serializers.Field()


class ModelSerializerWithNestedSerializer(serializers.ModelSerializer):
    nested = NestedSerializer(source='*')

    class Meta:
        model = Person


class NestedSerializerWithRenamedField(serializers.Serializer):
    renamed_info = serializers.Field(source='info')


class ModelSerializerWithNestedSerializerWithRenamedField(serializers.ModelSerializer):
    nested = NestedSerializerWithRenamedField(source='*')

    class Meta:
        model = Person


class PersonSerializerInvalidReadOnly(serializers.ModelSerializer):
    """
    Testing for #652.
    """
    info = serializers.Field(source='info')

    class Meta:
        model = Person
        fields = ('name', 'age', 'info')
        read_only_fields = ('age', 'info')


class AlbumsSerializer(serializers.ModelSerializer):

    class Meta:
        model = Album
        fields = ['title']  # lists are also valid options


class PositiveIntegerAsChoiceSerializer(serializers.ModelSerializer):
    class Meta:
        model = HasPositiveIntegerAsChoice
        fields = ['some_integer']


class BasicTests(TestCase):
    def setUp(self):
        self.comment = Comment(
            'tom@example.com',
            'Happy new year!',
            datetime.datetime(2012, 1, 1)
        )
        self.actionitem = ActionItem(title='Some to do item',)
        self.data = {
            'email': 'tom@example.com',
            'content': 'Happy new year!',
            'created': datetime.datetime(2012, 1, 1),
            'sub_comment': 'This wont change'
        }
        self.expected = {
            'email': 'tom@example.com',
            'content': 'Happy new year!',
            'created': datetime.datetime(2012, 1, 1),
            'sub_comment': 'And Merry Christmas!'
        }
        self.person_data = {'name': 'dwight', 'age': 35}
        self.person = Person(**self.person_data)
        self.person.save()

    def test_empty(self):
        serializer = CommentSerializer()
        expected = {
            'email': '',
            'content': '',
            'created': None
        }
        self.assertEqual(serializer.data, expected)

    def test_retrieve(self):
        serializer = CommentSerializer(self.comment)
        self.assertEqual(serializer.data, self.expected)

    def test_create(self):
        serializer = CommentSerializer(data=self.data)
        expected = self.comment
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, expected)
        self.assertFalse(serializer.object is expected)
        self.assertEqual(serializer.data['sub_comment'], 'And Merry Christmas!')

    def test_create_nested(self):
        """Test a serializer with nested data."""
        names = {'first': 'John', 'last': 'Doe', 'initials': 'jd'}
        data = {'ssn': '1234567890', 'names': names}
        serializer = PersonIdentifierSerializer(data=data)

        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, data)
        self.assertFalse(serializer.object is data)
        self.assertEqual(serializer.data['names'], names)

    def test_create_partial_nested(self):
        """Test a serializer with nested data which has missing fields."""
        names = {'first': 'John'}
        data = {'ssn': '1234567890', 'names': names}
        serializer = PersonIdentifierSerializer(data=data)

        expected_names = {'first': 'John', 'last': '', 'initials': ''}
        data['names'] = expected_names

        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, data)
        self.assertFalse(serializer.object is expected_names)
        self.assertEqual(serializer.data['names'], expected_names)

    def test_null_nested(self):
        """Test a serializer with a nonexistent nested field"""
        data = {'ssn': '1234567890'}
        serializer = PersonIdentifierSerializer(data=data)

        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, data)
        self.assertFalse(serializer.object is data)
        expected = {'ssn': '1234567890', 'names': None}
        self.assertEqual(serializer.data, expected)

    def test_update(self):
        serializer = CommentSerializer(self.comment, data=self.data)
        expected = self.comment
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, expected)
        self.assertTrue(serializer.object is expected)
        self.assertEqual(serializer.data['sub_comment'], 'And Merry Christmas!')

    def test_partial_update(self):
        msg = 'Merry New Year!'
        partial_data = {'content': msg}
        serializer = CommentSerializer(self.comment, data=partial_data)
        self.assertEqual(serializer.is_valid(), False)
        serializer = CommentSerializer(self.comment, data=partial_data, partial=True)
        expected = self.comment
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.object, expected)
        self.assertTrue(serializer.object is expected)
        self.assertEqual(serializer.data['content'], msg)

    def test_model_fields_as_expected(self):
        """
        Make sure that the fields returned are the same as defined
        in the Meta data
        """
        serializer = PersonSerializer(self.person)
        self.assertEqual(set(serializer.data.keys()),
                          set(['name', 'age', 'info']))

    def test_field_with_dictionary(self):
        """
        Make sure that dictionaries from fields are left intact
        """
        serializer = PersonSerializer(self.person)
        expected = self.person_data
        self.assertEqual(serializer.data['info'], expected)

    def test_read_only_fields(self):
        """
        Attempting to update fields set as read_only should have no effect.
        """
        serializer = PersonSerializer(self.person, data={'name': 'dwight', 'age': 99})
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(serializer.errors, {})
        # Assert age is unchanged (35)
        self.assertEqual(instance.age, self.person_data['age'])

    def test_invalid_read_only_fields(self):
        """
        Regression test for #652.
        """
        self.assertRaises(AssertionError, PersonSerializerInvalidReadOnly, [])

    def test_serializer_data_is_cleared_on_save(self):
        """
        Check _data attribute is cleared on `save()`

        Regression test for #1116
            — id field is not populated if `data` is accessed prior to `save()`
        """
        serializer = ActionItemSerializer(self.actionitem)
        self.assertIsNone(serializer.data.get('id',None), 'New instance. `id` should not be set.')
        serializer.save()
        self.assertIsNotNone(serializer.data.get('id',None), 'Model is saved. `id` should be set.')




class DictStyleSerializer(serializers.Serializer):
    """
    Note that we don't have any `restore_object` method, so the default
    case of simply returning a dict will apply.
    """
    email = serializers.EmailField()


class DictStyleSerializerTests(TestCase):
    def test_dict_style_deserialize(self):
        """
        Ensure serializers can deserialize into a dict.
        """
        data = {'email': 'foo@example.com'}
        serializer = DictStyleSerializer(data=data)
        self.assertTrue(serializer.is_valid())
        self.assertEqual(serializer.data, data)

    def test_dict_style_serialize(self):
        """
        Ensure serializers can serialize dict objects.
        """
        data = {'email': 'foo@example.com'}
        serializer = DictStyleSerializer(data)
        self.assertEqual(serializer.data, data)


class ValidationTests(TestCase):
    def setUp(self):
        self.comment = Comment(
            'tom@example.com',
            'Happy new year!',
            datetime.datetime(2012, 1, 1)
        )
        self.data = {
            'email': 'tom@example.com',
            'content': 'x' * 1001,
            'created': datetime.datetime(2012, 1, 1)
        }
        self.actionitem = ActionItem(title='Some to do item',)

    def test_create(self):
        serializer = CommentSerializer(data=self.data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'content': ['Ensure this value has at most 1000 characters (it has 1001).']})

    def test_update(self):
        serializer = CommentSerializer(self.comment, data=self.data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'content': ['Ensure this value has at most 1000 characters (it has 1001).']})

    def test_update_missing_field(self):
        data = {
            'content': 'xxx',
            'created': datetime.datetime(2012, 1, 1)
        }
        serializer = CommentSerializer(self.comment, data=data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'email': ['This field is required.']})

    def test_missing_bool_with_default(self):
        """Make sure that a boolean value with a 'False' value is not
        mistaken for not having a default."""
        data = {
            'title': 'Some action item',
            #No 'done' value.
        }
        serializer = ActionItemSerializer(self.actionitem, data=data)
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.errors, {})

    def test_cross_field_validation(self):

        class CommentSerializerWithCrossFieldValidator(CommentSerializer):

            def validate(self, attrs):
                if attrs["email"] not in attrs["content"]:
                    raise serializers.ValidationError("Email address not in content")
                return attrs

        data = {
            'email': 'tom@example.com',
            'content': 'A comment from tom@example.com',
            'created': datetime.datetime(2012, 1, 1)
        }

        serializer = CommentSerializerWithCrossFieldValidator(data=data)
        self.assertTrue(serializer.is_valid())

        data['content'] = 'A comment from foo@bar.com'

        serializer = CommentSerializerWithCrossFieldValidator(data=data)
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'non_field_errors': ['Email address not in content']})

    def test_null_is_true_fields(self):
        """
        Omitting a value for null-field should validate.
        """
        serializer = PersonSerializer(data={'name': 'marko'})
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.errors, {})

    def test_modelserializer_max_length_exceeded(self):
        data = {
            'title': 'x' * 201,
        }
        serializer = ActionItemSerializer(data=data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'title': ['Ensure this value has at most 200 characters (it has 201).']})

    def test_modelserializer_max_length_exceeded_with_custom_restore(self):
        """
        When overriding ModelSerializer.restore_object, validation tests should still apply.
        Regression test for #623.

        https://github.com/tomchristie/django-rest-framework/pull/623
        """
        data = {
            'title': 'x' * 201,
        }
        serializer = ActionItemSerializerCustomRestore(data=data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'title': ['Ensure this value has at most 200 characters (it has 201).']})

    def test_default_modelfield_max_length_exceeded(self):
        data = {
            'title': 'Testing "info" field...',
            'info': 'x' * 13,
        }
        serializer = ActionItemSerializer(data=data)
        self.assertEqual(serializer.is_valid(), False)
        self.assertEqual(serializer.errors, {'info': ['Ensure this value has at most 12 characters (it has 13).']})

    def test_datetime_validation_failure(self):
        """
        Test DateTimeField validation errors on non-str values.
        Regression test for #669.

        https://github.com/tomchristie/django-rest-framework/issues/669
        """
        data = self.data
        data['created'] = 0

        serializer = CommentSerializer(data=data)
        self.assertEqual(serializer.is_valid(), False)

        self.assertIn('created', serializer.errors)

    def test_missing_model_field_exception_msg(self):
        """
        Assert that a meaningful exception message is outputted when the model
        field is missing (e.g. when mistyping ``model``).
        """
        class BrokenModelSerializer(serializers.ModelSerializer):
            class Meta:
                fields = ['some_field']

        try:
            BrokenModelSerializer()
        except AssertionError as e:
            self.assertEqual(e.args[0], "Serializer class 'BrokenModelSerializer' is missing 'model' Meta option")
        except:
            self.fail('Wrong exception type thrown.')

    def test_writable_star_source_on_nested_serializer(self):
        """
        Assert that a nested serializer instantiated with source='*' correctly
        expands the data into the outer serializer.
        """
        serializer = ModelSerializerWithNestedSerializer(data={
            'name': 'marko',
            'nested': {'info': 'hi'}},
        )
        self.assertEqual(serializer.is_valid(), True)

    def test_writable_star_source_with_inner_source_fields(self):
        """
        Tests that a serializer with source="*" correctly expands the
        it's fields into the outer serializer even if they have their
        own 'source' parameters.
        """

        serializer = ModelSerializerWithNestedSerializerWithRenamedField(data={
            'name': 'marko',
            'nested': {'renamed_info': 'hi'}},
        )
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.errors, {})


class CustomValidationTests(TestCase):
    class CommentSerializerWithFieldValidator(CommentSerializer):

        def validate_email(self, attrs, source):
            attrs[source]
            return attrs

        def validate_content(self, attrs, source):
            value = attrs[source]
            if "test" not in value:
                raise serializers.ValidationError("Test not in value")
            return attrs

    def test_field_validation(self):
        data = {
            'email': 'tom@example.com',
            'content': 'A test comment',
            'created': datetime.datetime(2012, 1, 1)
        }

        serializer = self.CommentSerializerWithFieldValidator(data=data)
        self.assertTrue(serializer.is_valid())

        data['content'] = 'This should not validate'

        serializer = self.CommentSerializerWithFieldValidator(data=data)
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'content': ['Test not in value']})

    def test_missing_data(self):
        """
        Make sure that validate_content isn't called if the field is missing
        """
        incomplete_data = {
            'email': 'tom@example.com',
            'created': datetime.datetime(2012, 1, 1)
        }
        serializer = self.CommentSerializerWithFieldValidator(data=incomplete_data)
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'content': ['This field is required.']})

    def test_wrong_data(self):
        """
        Make sure that validate_content isn't called if the field input is wrong
        """
        wrong_data = {
            'email': 'not an email',
            'content': 'A test comment',
            'created': datetime.datetime(2012, 1, 1)
        }
        serializer = self.CommentSerializerWithFieldValidator(data=wrong_data)
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'email': ['Enter a valid email address.']})

    def test_partial_update(self):
        """
        Make sure that validate_email isn't called when partial=True and email
        isn't found in data.
        """
        initial_data = {
            'email': 'tom@example.com',
            'content': 'A test comment',
            'created': datetime.datetime(2012, 1, 1)
        }

        serializer = self.CommentSerializerWithFieldValidator(data=initial_data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.object

        new_content = 'An *updated* test comment'
        partial_data = {
            'content': new_content
        }

        serializer = self.CommentSerializerWithFieldValidator(instance=instance,
                                                              data=partial_data,
                                                              partial=True)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.object
        self.assertEqual(instance.content, new_content)


class PositiveIntegerAsChoiceTests(TestCase):
    def test_positive_integer_in_json_is_correctly_parsed(self):
        data = {'some_integer': 1}
        serializer = PositiveIntegerAsChoiceSerializer(data=data)
        self.assertEqual(serializer.is_valid(), True)


class ModelValidationTests(TestCase):
    def test_validate_unique(self):
        """
        Just check if serializers.ModelSerializer handles unique checks via .full_clean()
        """
        serializer = AlbumsSerializer(data={'title': 'a'})
        serializer.is_valid()
        serializer.save()
        second_serializer = AlbumsSerializer(data={'title': 'a'})
        self.assertFalse(second_serializer.is_valid())
        self.assertEqual(second_serializer.errors,  {'title': ['Album with this Title already exists.']})

    def test_foreign_key_is_null_with_partial(self):
        """
        Test ModelSerializer validation with partial=True

        Specifically test that a null foreign key does not pass validation
        """
        album = Album(title='test')
        album.save()

        class PhotoSerializer(serializers.ModelSerializer):
            class Meta:
                model = Photo

        photo_serializer = PhotoSerializer(data={'description': 'test', 'album': album.pk})
        self.assertTrue(photo_serializer.is_valid())
        photo = photo_serializer.save()

        # Updating only the album (foreign key)
        photo_serializer = PhotoSerializer(instance=photo, data={'album': ''}, partial=True)
        self.assertFalse(photo_serializer.is_valid())
        self.assertTrue('album' in photo_serializer.errors)
        self.assertEqual(photo_serializer.errors['album'], photo_serializer.error_messages['required'])

    def test_foreign_key_with_partial(self):
        """
        Test ModelSerializer validation with partial=True

        Specifically test foreign key validation.
        """

        album = Album(title='test')
        album.save()

        class PhotoSerializer(serializers.ModelSerializer):
            class Meta:
                model = Photo

        photo_serializer = PhotoSerializer(data={'description': 'test', 'album': album.pk})
        self.assertTrue(photo_serializer.is_valid())
        photo = photo_serializer.save()

        # Updating only the album (foreign key)
        photo_serializer = PhotoSerializer(instance=photo, data={'album': album.pk}, partial=True)
        self.assertTrue(photo_serializer.is_valid())
        self.assertTrue(photo_serializer.save())

        # Updating only the description
        photo_serializer = PhotoSerializer(instance=photo,
                                           data={'description': 'new'},
                                           partial=True)

        self.assertTrue(photo_serializer.is_valid())
        self.assertTrue(photo_serializer.save())


class RegexValidationTest(TestCase):
    def test_create_failed(self):
        serializer = BookSerializer(data={'isbn': '1234567890'})
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'isbn': ['isbn has to be exact 13 numbers']})

        serializer = BookSerializer(data={'isbn': '12345678901234'})
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'isbn': ['isbn has to be exact 13 numbers']})

        serializer = BookSerializer(data={'isbn': 'abcdefghijklm'})
        self.assertFalse(serializer.is_valid())
        self.assertEqual(serializer.errors, {'isbn': ['isbn has to be exact 13 numbers']})

    def test_create_success(self):
        serializer = BookSerializer(data={'isbn': '1234567890123'})
        self.assertTrue(serializer.is_valid())


class MetadataTests(TestCase):
    def test_empty(self):
        serializer = CommentSerializer()
        expected = {
            'email': serializers.CharField,
            'content': serializers.CharField,
            'created': serializers.DateTimeField
        }
        for field_name, field in expected.items():
            self.assertTrue(isinstance(serializer.data.fields[field_name], field))


class ManyToManyTests(TestCase):
    def setUp(self):
        class ManyToManySerializer(serializers.ModelSerializer):
            class Meta:
                model = ManyToManyModel

        self.serializer_class = ManyToManySerializer

        # An anchor instance to use for the relationship
        self.anchor = Anchor()
        self.anchor.save()

        # A model instance with a many to many relationship to the anchor
        self.instance = ManyToManyModel()
        self.instance.save()
        self.instance.rel.add(self.anchor)

        # A serialized representation of the model instance
        self.data = {'id': 1, 'rel': [self.anchor.id]}

    def test_retrieve(self):
        """
        Serialize an instance of a model with a ManyToMany relationship.
        """
        serializer = self.serializer_class(instance=self.instance)
        expected = self.data
        self.assertEqual(serializer.data, expected)

    def test_create(self):
        """
        Create an instance of a model with a ManyToMany relationship.
        """
        data = {'rel': [self.anchor.id]}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ManyToManyModel.objects.all()), 2)
        self.assertEqual(instance.pk, 2)
        self.assertEqual(list(instance.rel.all()), [self.anchor])

    def test_update(self):
        """
        Update an instance of a model with a ManyToMany relationship.
        """
        new_anchor = Anchor()
        new_anchor.save()
        data = {'rel': [self.anchor.id, new_anchor.id]}
        serializer = self.serializer_class(self.instance, data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ManyToManyModel.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(list(instance.rel.all()), [self.anchor, new_anchor])

    def test_create_empty_relationship(self):
        """
        Create an instance of a model with a ManyToMany relationship,
        containing no items.
        """
        data = {'rel': []}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ManyToManyModel.objects.all()), 2)
        self.assertEqual(instance.pk, 2)
        self.assertEqual(list(instance.rel.all()), [])

    def test_update_empty_relationship(self):
        """
        Update an instance of a model with a ManyToMany relationship,
        containing no items.
        """
        new_anchor = Anchor()
        new_anchor.save()
        data = {'rel': []}
        serializer = self.serializer_class(self.instance, data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ManyToManyModel.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(list(instance.rel.all()), [])

    def test_create_empty_relationship_flat_data(self):
        """
        Create an instance of a model with a ManyToMany relationship,
        containing no items, using a representation that does not support
        lists (eg form data).
        """
        data = MultiValueDict()
        data.setlist('rel', [''])
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ManyToManyModel.objects.all()), 2)
        self.assertEqual(instance.pk, 2)
        self.assertEqual(list(instance.rel.all()), [])


class ReadOnlyManyToManyTests(TestCase):
    def setUp(self):
        class ReadOnlyManyToManySerializer(serializers.ModelSerializer):
            rel = serializers.RelatedField(many=True, read_only=True)

            class Meta:
                model = ReadOnlyManyToManyModel

        self.serializer_class = ReadOnlyManyToManySerializer

        # An anchor instance to use for the relationship
        self.anchor = Anchor()
        self.anchor.save()

        # A model instance with a many to many relationship to the anchor
        self.instance = ReadOnlyManyToManyModel()
        self.instance.save()
        self.instance.rel.add(self.anchor)

        # A serialized representation of the model instance
        self.data = {'rel': [self.anchor.id], 'id': 1, 'text': 'anchor'}

    def test_update(self):
        """
        Attempt to update an instance of a model with a ManyToMany
        relationship.  Not updated due to read_only=True
        """
        new_anchor = Anchor()
        new_anchor.save()
        data = {'rel': [self.anchor.id, new_anchor.id]}
        serializer = self.serializer_class(self.instance, data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ReadOnlyManyToManyModel.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        # rel is still as original (1 entry)
        self.assertEqual(list(instance.rel.all()), [self.anchor])

    def test_update_without_relationship(self):
        """
        Attempt to update an instance of a model where many to ManyToMany
        relationship is not supplied.  Not updated due to read_only=True
        """
        new_anchor = Anchor()
        new_anchor.save()
        data = {}
        serializer = self.serializer_class(self.instance, data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(ReadOnlyManyToManyModel.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        # rel is still as original (1 entry)
        self.assertEqual(list(instance.rel.all()), [self.anchor])


class DefaultValueTests(TestCase):
    def setUp(self):
        class DefaultValueSerializer(serializers.ModelSerializer):
            class Meta:
                model = DefaultValueModel

        self.serializer_class = DefaultValueSerializer
        self.objects = DefaultValueModel.objects

    def test_create_using_default(self):
        data = {}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(self.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(instance.text, 'foobar')

    def test_create_overriding_default(self):
        data = {'text': 'overridden'}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(self.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(instance.text, 'overridden')

    def test_partial_update_default(self):
        """ Regression test for issue #532 """
        data = {'text': 'overridden'}
        serializer = self.serializer_class(data=data, partial=True)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()

        data = {'extra': 'extra_value'}
        serializer = self.serializer_class(instance=instance, data=data, partial=True)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()

        self.assertEqual(instance.extra, 'extra_value')
        self.assertEqual(instance.text, 'overridden')


class CallableDefaultValueTests(TestCase):
    def setUp(self):
        class CallableDefaultValueSerializer(serializers.ModelSerializer):
            class Meta:
                model = CallableDefaultValueModel

        self.serializer_class = CallableDefaultValueSerializer
        self.objects = CallableDefaultValueModel.objects

    def test_create_using_default(self):
        data = {}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(self.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(instance.text, 'foobar')

    def test_create_overriding_default(self):
        data = {'text': 'overridden'}
        serializer = self.serializer_class(data=data)
        self.assertEqual(serializer.is_valid(), True)
        instance = serializer.save()
        self.assertEqual(len(self.objects.all()), 1)
        self.assertEqual(instance.pk, 1)
        self.assertEqual(instance.text, 'overridden')


class ManyRelatedTests(TestCase):
    def test_reverse_relations(self):
        post = BlogPost.objects.create(title="Test blog post")
        post.blogpostcomment_set.create(text="I hate this blog post")
        post.blogpostcomment_set.create(text="I love this blog post")

        class BlogPostCommentSerializer(serializers.Serializer):
            text = serializers.CharField()

        class BlogPostSerializer(serializers.Serializer):
            title = serializers.CharField()
            comments = BlogPostCommentSerializer(source='blogpostcomment_set')

        serializer = BlogPostSerializer(instance=post)
        expected = {
            'title': 'Test blog post',
            'comments': [
                {'text': 'I hate this blog post'},
                {'text': 'I love this blog post'}
            ]
        }

        self.assertEqual(serializer.data, expected)

    def test_include_reverse_relations(self):
        post = BlogPost.objects.create(title="Test blog post")
        post.blogpostcomment_set.create(text="I hate this blog post")
        post.blogpostcomment_set.create(text="I love this blog post")

        class BlogPostSerializer(serializers.ModelSerializer):
            class Meta:
                model = BlogPost
                fields = ('id', 'title', 'blogpostcomment_set')

        serializer = BlogPostSerializer(instance=post)
        expected = {
            'id': 1, 'title': 'Test blog post', 'blogpostcomment_set': [1, 2]
        }
        self.assertEqual(serializer.data, expected)

    def test_depth_include_reverse_relations(self):
        post = BlogPost.objects.create(title="Test blog post")
        post.blogpostcomment_set.create(text="I hate this blog post")
        post.blogpostcomment_set.create(text="I love this blog post")

        class BlogPostSerializer(serializers.ModelSerializer):
            class Meta:
                model = BlogPost
                fields = ('id', 'title', 'blogpostcomment_set')
                depth = 1

        serializer = BlogPostSerializer(instance=post)
        expected = {
            'id': 1, 'title': 'Test blog post',
            'blogpostcomment_set': [
                {'id': 1, 'text': 'I hate this blog post', 'blog_post': 1},
                {'id': 2, 'text': 'I love this blog post', 'blog_post': 1}
            ]
        }
        self.assertEqual(serializer.data, expected)

    def test_callable_source(self):
        post = BlogPost.objects.create(title="Test blog post")
        post.blogpostcomment_set.create(text="I love this blog post")

        class BlogPostCommentSerializer(serializers.Serializer):
            text = serializers.CharField()

        class BlogPostSerializer(serializers.Serializer):
            title = serializers.CharField()
            first_comment = BlogPostCommentSerializer(source='get_first_comment')

        serializer = BlogPostSerializer(post)

        expected = {
            'title': 'Test blog post',
            'first_comment': {'text': 'I love this blog post'}
        }
        self.assertEqual(serializer.data, expected)


class RelatedTraversalTest(TestCase):
    def test_nested_traversal(self):
        """
        Source argument should support dotted.source notation.
        """
        user = Person.objects.create(name="django")
        post = BlogPost.objects.create(title="Test blog post", writer=user)
        post.blogpostcomment_set.create(text="I love this blog post")

        class PersonSerializer(serializers.ModelSerializer):
            class Meta:
                model = Person
                fields = ("name", "age")

        class BlogPostCommentSerializer(serializers.ModelSerializer):
            class Meta:
                model = BlogPostComment
                fields = ("text", "post_owner")

            text = serializers.CharField()
            post_owner = PersonSerializer(source='blog_post.writer')

        class BlogPostSerializer(serializers.Serializer):
            title = serializers.CharField()
            comments = BlogPostCommentSerializer(source='blogpostcomment_set')

        serializer = BlogPostSerializer(instance=post)

        expected = {
            'title': 'Test blog post',
            'comments': [{
                'text': 'I love this blog post',
                'post_owner': {
                    "name": "django",
                    "age": None
                }
            }]
        }

        self.assertEqual(serializer.data, expected)

    def test_nested_traversal_with_none(self):
        """
        If a component of the dotted.source is None, return None for the field.
        """
        from rest_framework.tests.models import NullableForeignKeySource
        instance = NullableForeignKeySource.objects.create(name='Source with null FK')

        class NullableSourceSerializer(serializers.Serializer):
            target_name = serializers.Field(source='target.name')

        serializer = NullableSourceSerializer(instance=instance)

        expected = {
            'target_name': None,
        }

        self.assertEqual(serializer.data, expected)


class SerializerMethodFieldTests(TestCase):
    def setUp(self):

        class BoopSerializer(serializers.Serializer):
            beep = serializers.SerializerMethodField('get_beep')
            boop = serializers.Field()
            boop_count = serializers.SerializerMethodField('get_boop_count')

            def get_beep(self, obj):
                return 'hello!'

            def get_boop_count(self, obj):
                return len(obj.boop)

        self.serializer_class = BoopSerializer

    def test_serializer_method_field(self):

        class MyModel(object):
            boop = ['a', 'b', 'c']

        source_data = MyModel()

        serializer = self.serializer_class(source_data)

        expected = {
            'beep': 'hello!',
            'boop': ['a', 'b', 'c'],
            'boop_count': 3,
        }

        self.assertEqual(serializer.data, expected)


# Test for issue #324
class BlankFieldTests(TestCase):
    def setUp(self):

        class BlankFieldModelSerializer(serializers.ModelSerializer):
            class Meta:
                model = BlankFieldModel

        class BlankFieldSerializer(serializers.Serializer):
            title = serializers.CharField(required=False)

        class NotBlankFieldModelSerializer(serializers.ModelSerializer):
            class Meta:
                model = BasicModel

        class NotBlankFieldSerializer(serializers.Serializer):
            title = serializers.CharField()

        self.model_serializer_class = BlankFieldModelSerializer
        self.serializer_class = BlankFieldSerializer
        self.not_blank_model_serializer_class = NotBlankFieldModelSerializer
        self.not_blank_serializer_class = NotBlankFieldSerializer
        self.data = {'title': ''}

    def test_create_blank_field(self):
        serializer = self.serializer_class(data=self.data)
        self.assertEqual(serializer.is_valid(), True)

    def test_create_model_blank_field(self):
        serializer = self.model_serializer_class(data=self.data)
        self.assertEqual(serializer.is_valid(), True)

    def test_create_model_null_field(self):
        serializer = self.model_serializer_class(data={'title': None})
        self.assertEqual(serializer.is_valid(), True)

    def test_create_not_blank_field(self):
        """
        Test to ensure blank data in a field not marked as blank=True
        is considered invalid in a non-model serializer
        """
        serializer = self.not_blank_serializer_class(data=self.data)
        self.assertEqual(serializer.is_valid(), False)

    def test_create_model_not_blank_field(self):
        """
        Test to ensure blank data in a field not marked as blank=True
        is considered invalid in a model serializer
        """
        serializer = self.not_blank_model_serializer_class(data=self.data)
        self.assertEqual(serializer.is_valid(), False)

    def test_create_model_empty_field(self):
        serializer = self.model_serializer_class(data={})
        self.assertEqual(serializer.is_valid(), True)


#test for issue #460
class SerializerPickleTests(TestCase):
    """
    Test pickleability of the output of Serializers
    """
    def test_pickle_simple_model_serializer_data(self):
        """
        Test simple serializer
        """
        pickle.dumps(PersonSerializer(Person(name="Methusela", age=969)).data)

    def test_pickle_inner_serializer(self):
        """
        Test pickling a serializer whose resulting .data (a SortedDictWithMetadata) will
        have unpickleable meta data--in order to make sure metadata doesn't get pulled into the pickle.
        See DictWithMetadata.__getstate__
        """
        class InnerPersonSerializer(serializers.ModelSerializer):
            class Meta:
                model = Person
                fields = ('name', 'age')
        pickle.dumps(InnerPersonSerializer(Person(name="Noah", age=950)).data, 0)

    def test_getstate_method_should_not_return_none(self):
        """
        Regression test for #645.
        """
        data = serializers.DictWithMetadata({1: 1})
        self.assertEqual(data.__getstate__(), serializers.SortedDict({1: 1}))

    def test_serializer_data_is_pickleable(self):
        """
        Another regression test for #645.
        """
        data = serializers.SortedDictWithMetadata({1: 1})
        repr(pickle.loads(pickle.dumps(data, 0)))


# test for issue #725
class SeveralChoicesModel(models.Model):
    color = models.CharField(
        max_length=10,
        choices=[('red', 'Red'), ('green', 'Green'), ('blue', 'Blue')],
        blank=False
    )
    drink = models.CharField(
        max_length=10,
        choices=[('beer', 'Beer'), ('wine', 'Wine'), ('cider', 'Cider')],
        blank=False,
        default='beer'
    )
    os = models.CharField(
        max_length=10,
        choices=[('linux', 'Linux'), ('osx', 'OSX'), ('windows', 'Windows')],
        blank=True
    )
    music_genre = models.CharField(
        max_length=10,
        choices=[('rock', 'Rock'), ('metal', 'Metal'), ('grunge', 'Grunge')],
        blank=True,
        default='metal'
    )


class SerializerChoiceFields(TestCase):

    def setUp(self):
        super(SerializerChoiceFields, self).setUp()

        class SeveralChoicesSerializer(serializers.ModelSerializer):
            class Meta:
                model = SeveralChoicesModel
                fields = ('color', 'drink', 'os', 'music_genre')

        self.several_choices_serializer = SeveralChoicesSerializer

    def test_choices_blank_false_not_default(self):
        serializer = self.several_choices_serializer()
        self.assertEqual(
            serializer.fields['color'].choices,
            [('red', 'Red'), ('green', 'Green'), ('blue', 'Blue')]
        )

    def test_choices_blank_false_with_default(self):
        serializer = self.several_choices_serializer()
        self.assertEqual(
            serializer.fields['drink'].choices,
            [('beer', 'Beer'), ('wine', 'Wine'), ('cider', 'Cider')]
        )

    def test_choices_blank_true_not_default(self):
        serializer = self.several_choices_serializer()
        self.assertEqual(
            serializer.fields['os'].choices,
            BLANK_CHOICE_DASH + [('linux', 'Linux'), ('osx', 'OSX'), ('windows', 'Windows')]
        )

    def test_choices_blank_true_with_default(self):
        serializer = self.several_choices_serializer()
        self.assertEqual(
            serializer.fields['music_genre'].choices,
            BLANK_CHOICE_DASH + [('rock', 'Rock'), ('metal', 'Metal'), ('grunge', 'Grunge')]
        )


# Regression tests for #675
class Ticket(models.Model):
    assigned = models.ForeignKey(
        Person, related_name='assigned_tickets')
    reviewer = models.ForeignKey(
        Person, blank=True, null=True, related_name='reviewed_tickets')


class SerializerRelatedChoicesTest(TestCase):

    def setUp(self):
        super(SerializerRelatedChoicesTest, self).setUp()

        class RelatedChoicesSerializer(serializers.ModelSerializer):
            class Meta:
                model = Ticket
                fields = ('assigned', 'reviewer')

        self.related_fields_serializer = RelatedChoicesSerializer

    def test_empty_queryset_required(self):
        serializer = self.related_fields_serializer()
        self.assertEqual(serializer.fields['assigned'].queryset.count(), 0)
        self.assertEqual(
            [x for x in serializer.fields['assigned'].widget.choices],
            []
        )

    def test_empty_queryset_not_required(self):
        serializer = self.related_fields_serializer()
        self.assertEqual(serializer.fields['reviewer'].queryset.count(), 0)
        self.assertEqual(
            [x for x in serializer.fields['reviewer'].widget.choices],
            [('', '---------')]
        )

    def test_with_some_persons_required(self):
        Person.objects.create(name="Lionel Messi")
        Person.objects.create(name="Xavi Hernandez")
        serializer = self.related_fields_serializer()
        self.assertEqual(serializer.fields['assigned'].queryset.count(), 2)
        self.assertEqual(
            [x for x in serializer.fields['assigned'].widget.choices],
            [(1, 'Person object - 1'), (2, 'Person object - 2')]
        )

    def test_with_some_persons_not_required(self):
        Person.objects.create(name="Lionel Messi")
        Person.objects.create(name="Xavi Hernandez")
        serializer = self.related_fields_serializer()
        self.assertEqual(serializer.fields['reviewer'].queryset.count(), 2)
        self.assertEqual(
            [x for x in serializer.fields['reviewer'].widget.choices],
            [('', '---------'), (1, 'Person object - 1'), (2, 'Person object - 2')]
        )


class DepthTest(TestCase):
    def test_implicit_nesting(self):

        writer = Person.objects.create(name="django", age=1)
        post = BlogPost.objects.create(title="Test blog post", writer=writer)
        comment = BlogPostComment.objects.create(text="Test blog post comment", blog_post=post)

        class BlogPostCommentSerializer(serializers.ModelSerializer):
            class Meta:
                model = BlogPostComment
                depth = 2

        serializer = BlogPostCommentSerializer(instance=comment)
        expected = {'id': 1, 'text': 'Test blog post comment', 'blog_post': {'id': 1, 'title': 'Test blog post',
                    'writer': {'id': 1, 'name': 'django', 'age': 1}}}

        self.assertEqual(serializer.data, expected)

    def test_explicit_nesting(self):
        writer = Person.objects.create(name="django", age=1)
        post = BlogPost.objects.create(title="Test blog post", writer=writer)
        comment = BlogPostComment.objects.create(text="Test blog post comment", blog_post=post)

        class PersonSerializer(serializers.ModelSerializer):
            class Meta:
                model = Person

        class BlogPostSerializer(serializers.ModelSerializer):
            writer = PersonSerializer()

            class Meta:
                model = BlogPost

        class BlogPostCommentSerializer(serializers.ModelSerializer):
            blog_post = BlogPostSerializer()

            class Meta:
                model = BlogPostComment

        serializer = BlogPostCommentSerializer(instance=comment)
        expected = {'id': 1, 'text': 'Test blog post comment', 'blog_post': {'id': 1, 'title': 'Test blog post',
                    'writer': {'id': 1, 'name': 'django', 'age': 1}}}

        self.assertEqual(serializer.data, expected)


class NestedSerializerContextTests(TestCase):

    def test_nested_serializer_context(self):
        """
        Regression for #497

        https://github.com/tomchristie/django-rest-framework/issues/497
        """
        class PhotoSerializer(serializers.ModelSerializer):
            class Meta:
                model = Photo
                fields = ("description", "callable")

            callable = serializers.SerializerMethodField('_callable')

            def _callable(self, instance):
                if not 'context_item' in self.context:
                    raise RuntimeError("context isn't getting passed into 2nd level nested serializer")
                return "success"

        class AlbumSerializer(serializers.ModelSerializer):
            class Meta:
                model = Album
                fields = ("photo_set", "callable")

            photo_set = PhotoSerializer(source="photo_set")
            callable = serializers.SerializerMethodField("_callable")

            def _callable(self, instance):
                if not 'context_item' in self.context:
                    raise RuntimeError("context isn't getting passed into 1st level nested serializer")
                return "success"

        class AlbumCollection(object):
            albums = None

        class AlbumCollectionSerializer(serializers.Serializer):
            albums = AlbumSerializer(source="albums")

        album1 = Album.objects.create(title="album 1")
        album2 = Album.objects.create(title="album 2")
        Photo.objects.create(description="Bigfoot", album=album1)
        Photo.objects.create(description="Unicorn", album=album1)
        Photo.objects.create(description="Yeti", album=album2)
        Photo.objects.create(description="Sasquatch", album=album2)
        album_collection = AlbumCollection()
        album_collection.albums = [album1, album2]

        # This will raise RuntimeError if context doesn't get passed correctly to the nested Serializers
        AlbumCollectionSerializer(album_collection, context={'context_item': 'album context'}).data


class DeserializeListTestCase(TestCase):

    def setUp(self):
        self.data = {
            'email': 'nobody@nowhere.com',
            'content': 'This is some test content',
            'created': datetime.datetime(2013, 3, 7),
        }

    def test_no_errors(self):
        data = [self.data.copy() for x in range(0, 3)]
        serializer = CommentSerializer(data=data, many=True)
        self.assertTrue(serializer.is_valid())
        self.assertTrue(isinstance(serializer.object, list))
        self.assertTrue(
            all((isinstance(item, Comment) for item in serializer.object))
        )

    def test_errors_return_as_list(self):
        invalid_item = self.data.copy()
        invalid_item['email'] = ''
        data = [self.data.copy(), invalid_item, self.data.copy()]

        serializer = CommentSerializer(data=data, many=True)
        self.assertFalse(serializer.is_valid())
        expected = [{}, {'email': ['This field is required.']}, {}]
        self.assertEqual(serializer.errors, expected)


# Test for issue 747

class LazyStringModel(object):
    def __init__(self, lazystring):
        self.lazystring = lazystring


class LazyStringSerializer(serializers.Serializer):
    lazystring = serializers.Field()

    def restore_object(self, attrs, instance=None):
        if instance is not None:
            instance.lazystring = attrs.get('lazystring', instance.lazystring)
            return instance
        return LazyStringModel(**attrs)


class LazyStringsTestCase(TestCase):
    def setUp(self):
        self.model = LazyStringModel(lazystring=_('lazystring'))

    def test_lazy_strings_are_translated(self):
        serializer = LazyStringSerializer(self.model)
        self.assertEqual(type(serializer.data['lazystring']),
                         type('lazystring'))


# Test for issue #467

class FieldLabelTest(TestCase):
    def setUp(self):
        self.serializer_class = BasicModelSerializer

    def test_label_from_model(self):
        """
        Validates that label and help_text are correctly copied from the model class.
        """
        serializer = self.serializer_class()
        text_field = serializer.fields['text']

        self.assertEqual('Text comes here', text_field.label)
        self.assertEqual('Text description.', text_field.help_text)

    def test_field_ctor(self):
        """
        This is check that ctor supports both label and help_text.
        """
        self.assertEqual('Label', fields.Field(label='Label', help_text='Help').label)
        self.assertEqual('Help', fields.CharField(label='Label', help_text='Help').help_text)
        self.assertEqual('Label', relations.HyperlinkedRelatedField(view_name='fake', label='Label', help_text='Help', many=True).label)


# Test for issue #961

class ManyFieldHelpTextTest(TestCase):
    def test_help_text_no_hold_down_control_msg(self):
        """
        Validate that help_text doesn't contain the 'Hold down "Control" ...'
        message that Django appends to choice fields.
        """
        rel_field = fields.Field(help_text=ManyToManyModel._meta.get_field('rel').help_text)
        self.assertEqual('Some help text.', rel_field.help_text)


class AttributeMappingOnAutogeneratedFieldsTests(TestCase):

    def setUp(self):
        class AMOAFModel(RESTFrameworkModel):
            char_field = models.CharField(max_length=1024, blank=True)
            comma_separated_integer_field = models.CommaSeparatedIntegerField(max_length=1024, blank=True)
            decimal_field = models.DecimalField(max_digits=64, decimal_places=32, blank=True)
            email_field = models.EmailField(max_length=1024, blank=True)
            file_field = models.FileField(max_length=1024, blank=True)
            image_field = models.ImageField(max_length=1024, blank=True)
            slug_field = models.SlugField(max_length=1024, blank=True)
            url_field = models.URLField(max_length=1024, blank=True)

        class AMOAFSerializer(serializers.ModelSerializer):
            class Meta:
                model = AMOAFModel

        self.serializer_class = AMOAFSerializer
        self.fields_attributes = {
            'char_field': [
                ('max_length', 1024),
            ],
            'comma_separated_integer_field': [
                ('max_length', 1024),
            ],
            'decimal_field': [
                ('max_digits', 64),
                ('decimal_places', 32),
            ],
            'email_field': [
                ('max_length', 1024),
            ],
            'file_field': [
                ('max_length', 1024),
            ],
            'image_field': [
                ('max_length', 1024),
            ],
            'slug_field': [
                ('max_length', 1024),
            ],
            'url_field': [
                ('max_length', 1024),
            ],
        }

    def field_test(self, field):
        serializer = self.serializer_class(data={})
        self.assertEqual(serializer.is_valid(), True)

        for attribute in self.fields_attributes[field]:
            self.assertEqual(
                getattr(serializer.fields[field], attribute[0]),
                attribute[1]
            )

    def test_char_field(self):
        self.field_test('char_field')

    def test_comma_separated_integer_field(self):
        self.field_test('comma_separated_integer_field')

    def test_decimal_field(self):
        self.field_test('decimal_field')

    def test_email_field(self):
        self.field_test('email_field')

    def test_file_field(self):
        self.field_test('file_field')

    def test_image_field(self):
        self.field_test('image_field')

    def test_slug_field(self):
        self.field_test('slug_field')

    def test_url_field(self):
        self.field_test('url_field')


class DefaultValuesOnAutogeneratedFieldsTests(TestCase):

    def setUp(self):
        class DVOAFModel(RESTFrameworkModel):
            positive_integer_field = models.PositiveIntegerField(blank=True)
            positive_small_integer_field = models.PositiveSmallIntegerField(blank=True)
            email_field = models.EmailField(blank=True)
            file_field = models.FileField(blank=True)
            image_field = models.ImageField(blank=True)
            slug_field = models.SlugField(blank=True)
            url_field = models.URLField(blank=True)

        class DVOAFSerializer(serializers.ModelSerializer):
            class Meta:
                model = DVOAFModel

        self.serializer_class = DVOAFSerializer
        self.fields_attributes = {
            'positive_integer_field': [
                ('min_value', 0),
            ],
            'positive_small_integer_field': [
                ('min_value', 0),
            ],
            'email_field': [
                ('max_length', 75),
            ],
            'file_field': [
                ('max_length', 100),
            ],
            'image_field': [
                ('max_length', 100),
            ],
            'slug_field': [
                ('max_length', 50),
            ],
            'url_field': [
                ('max_length', 200),
            ],
        }

    def field_test(self, field):
        serializer = self.serializer_class(data={})
        self.assertEqual(serializer.is_valid(), True)

        for attribute in self.fields_attributes[field]:
            self.assertEqual(
                getattr(serializer.fields[field], attribute[0]),
                attribute[1]
            )

    def test_positive_integer_field(self):
        self.field_test('positive_integer_field')

    def test_positive_small_integer_field(self):
        self.field_test('positive_small_integer_field')

    def test_email_field(self):
        self.field_test('email_field')

    def test_file_field(self):
        self.field_test('file_field')

    def test_image_field(self):
        self.field_test('image_field')

    def test_slug_field(self):
        self.field_test('slug_field')

    def test_url_field(self):
        self.field_test('url_field')


class MetadataSerializer(serializers.Serializer):
    field1 = serializers.CharField(3, required=True)
    field2 = serializers.CharField(10, required=False)


class MetadataSerializerTestCase(TestCase):
    def setUp(self):
        self.serializer = MetadataSerializer()

    def test_serializer_metadata(self):
        metadata = self.serializer.metadata()
        expected = {
            'field1': {
                'required': True,
                'max_length': 3,
                'type': 'string',
                'read_only': False
            },
            'field2': {
                'required': False,
                'max_length': 10,
                'type': 'string',
                'read_only': False
            }
        }
        self.assertEqual(expected, metadata)


### Regression test for #840

class SimpleModel(models.Model):
    text = models.CharField(max_length=100)


class SimpleModelSerializer(serializers.ModelSerializer):
    text = serializers.CharField()
    other = serializers.CharField()

    class Meta:
        model = SimpleModel

    def validate_other(self, attrs, source):
        del attrs['other']
        return attrs


class FieldValidationRemovingAttr(TestCase):
    def test_removing_non_model_field_in_validation(self):
        """
        Removing an attr during field valiation should ensure that it is not
        passed through when restoring the object.

        This allows additional non-model fields to be supported.

        Regression test for #840.
        """
        serializer = SimpleModelSerializer(data={'text': 'foo', 'other': 'bar'})
        self.assertTrue(serializer.is_valid())
        serializer.save()
        self.assertEqual(serializer.object.text, 'foo')


### Regression test for #878

class SimpleTargetModel(models.Model):
    text = models.CharField(max_length=100)


class SimplePKSourceModelSerializer(serializers.Serializer):
    targets = serializers.PrimaryKeyRelatedField(queryset=SimpleTargetModel.objects.all(), many=True)
    text = serializers.CharField()


class SimpleSlugSourceModelSerializer(serializers.Serializer):
    targets = serializers.SlugRelatedField(queryset=SimpleTargetModel.objects.all(), many=True, slug_field='pk')
    text = serializers.CharField()


class SerializerSupportsManyRelationships(TestCase):
    def setUp(self):
        SimpleTargetModel.objects.create(text='foo')
        SimpleTargetModel.objects.create(text='bar')

    def test_serializer_supports_pk_many_relationships(self):
        """
        Regression test for #878.

        Note that pk behavior has a different code path to usual cases,
        for performance reasons.
        """
        serializer = SimplePKSourceModelSerializer(data={'text': 'foo', 'targets': [1, 2]})
        self.assertTrue(serializer.is_valid())
        self.assertEqual(serializer.data, {'text': 'foo', 'targets': [1, 2]})

    def test_serializer_supports_slug_many_relationships(self):
        """
        Regression test for #878.
        """
        serializer = SimpleSlugSourceModelSerializer(data={'text': 'foo', 'targets': [1, 2]})
        self.assertTrue(serializer.is_valid())
        self.assertEqual(serializer.data, {'text': 'foo', 'targets': [1, 2]})


class TransformMethodsSerializer(serializers.Serializer):
    a = serializers.CharField()
    b_renamed = serializers.CharField(source='b')

    def transform_a(self, obj, value):
        return value.lower()

    def transform_b_renamed(self, obj, value):
        if value is not None:
            return 'and ' + value


class TestSerializerTransformMethods(TestCase):
    def setUp(self):
        self.s = TransformMethodsSerializer()

    def test_transform_methods(self):
        self.assertEqual(
            self.s.to_native({'a': 'GREEN EGGS', 'b': 'HAM'}),
            {
                'a': 'green eggs',
                'b_renamed': 'and HAM',
            }
        )

    def test_missing_fields(self):
        self.assertEqual(
            self.s.to_native({'a': 'GREEN EGGS'}),
            {
                'a': 'green eggs',
                'b_renamed': None,
            }
        )


class DefaultTrueBooleanModel(models.Model):
    cat = models.BooleanField(default=True)
    dog = models.BooleanField(default=False)


class SerializerDefaultTrueBoolean(TestCase):

    def setUp(self):
        super(SerializerDefaultTrueBoolean, self).setUp()

        class DefaultTrueBooleanSerializer(serializers.ModelSerializer):
            class Meta:
                model = DefaultTrueBooleanModel
                fields = ('cat', 'dog')

        self.default_true_boolean_serializer = DefaultTrueBooleanSerializer

    def test_enabled_as_false(self):
        serializer = self.default_true_boolean_serializer(data={'cat': False,
                                                                'dog': False})
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.data['cat'], False)
        self.assertEqual(serializer.data['dog'], False)

    def test_enabled_as_true(self):
        serializer = self.default_true_boolean_serializer(data={'cat': True,
                                                                'dog': True})
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.data['cat'], True)
        self.assertEqual(serializer.data['dog'], True)

    def test_enabled_partial(self):
        serializer = self.default_true_boolean_serializer(data={'cat': False},
                                                          partial=True)
        self.assertEqual(serializer.is_valid(), True)
        self.assertEqual(serializer.data['cat'], False)
        self.assertEqual(serializer.data['dog'], False)

        
class BoolenFieldTypeTest(TestCase):
    '''
    Ensure the various Boolean based model fields are rendered as the proper
    field type
    
    '''
    
    def setUp(self):
        '''
        Setup an ActionItemSerializer for BooleanTesting
        '''
        data = {
            'title': 'b' * 201,
        }
        self.serializer = ActionItemSerializer(data=data)

    def test_booleanfield_type(self):
        '''
        Test that BooleanField is infered from models.BooleanField
        '''
        bfield = self.serializer.get_fields()['done']
        self.assertEqual(type(bfield), fields.BooleanField)
    
    def test_nullbooleanfield_type(self):
        '''
        Test that BooleanField is infered from models.NullBooleanField 
        
        https://groups.google.com/forum/#!topic/django-rest-framework/D9mXEftpuQ8
        '''
        bfield = self.serializer.get_fields()['started']
        self.assertEqual(type(bfield), fields.BooleanField)