Tests for relational fields

1 files changed, 440 insertions, 446 deletions

diff --git a/tests/test_relations_pk.py b/tests/test_relations_pk.py
index 031a79b3..da3c5786 100644
--- a/tests/test_relations_pk.py
+++ b/tests/test_relations_pk.py
@@ -1,446 +1,443 @@
-# from __future__ import unicode_literals
-# from django.db import models
-# from django.test import TestCase
-# from django.utils import six
-# from rest_framework import serializers
-# from tests.models import (
-#     BlogPost, ManyToManyTarget, ManyToManySource, ForeignKeyTarget, ForeignKeySource,
-#     NullableForeignKeySource, OneToOneTarget, NullableOneToOneSource,
-# )
-
-
-# # ManyToMany
-# class ManyToManyTargetSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = ManyToManyTarget
-#         fields = ('id', 'name', 'sources')
-
-
-# class ManyToManySourceSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = ManyToManySource
-#         fields = ('id', 'name', 'targets')
-
-
-# # ForeignKey
-# class ForeignKeyTargetSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = ForeignKeyTarget
-#         fields = ('id', 'name', 'sources')
-
-
-# class ForeignKeySourceSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = ForeignKeySource
-#         fields = ('id', 'name', 'target')
-
-
-# # Nullable ForeignKey
-# class NullableForeignKeySourceSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = NullableForeignKeySource
-#         fields = ('id', 'name', 'target')
-
-
-# # Nullable OneToOne
-# class NullableOneToOneTargetSerializer(serializers.ModelSerializer):
-#     class Meta:
-#         model = OneToOneTarget
-#         fields = ('id', 'name', 'nullable_source')
-
-
-# # TODO: Add test that .data cannot be accessed prior to .is_valid
-
-# class PKManyToManyTests(TestCase):
-#     def setUp(self):
-#         for idx in range(1, 4):
-#             target = ManyToManyTarget(name='target-%d' % idx)
-#             target.save()
-#             source = ManyToManySource(name='source-%d' % idx)
-#             source.save()
-#             for target in ManyToManyTarget.objects.all():
-#                 source.targets.add(target)
-
-#     def test_many_to_many_retrieve(self):
-#         queryset = ManyToManySource.objects.all()
-#         serializer = ManyToManySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'targets': [1]},
-#             {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
-#             {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_reverse_many_to_many_retrieve(self):
-#         queryset = ManyToManyTarget.objects.all()
-#         serializer = ManyToManyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
-#             {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
-#             {'id': 3, 'name': 'target-3', 'sources': [3]}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_many_to_many_update(self):
-#         data = {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]}
-#         instance = ManyToManySource.objects.get(pk=1)
-#         serializer = ManyToManySourceSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         serializer.save()
-#         self.assertEqual(serializer.data, data)
-
-#         # Ensure source 1 is updated, and everything else is as expected
-#         queryset = ManyToManySource.objects.all()
-#         serializer = ManyToManySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]},
-#             {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
-#             {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_reverse_many_to_many_update(self):
-#         data = {'id': 1, 'name': 'target-1', 'sources': [1]}
-#         instance = ManyToManyTarget.objects.get(pk=1)
-#         serializer = ManyToManyTargetSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         serializer.save()
-#         self.assertEqual(serializer.data, data)
-
-#         # Ensure target 1 is updated, and everything else is as expected
-#         queryset = ManyToManyTarget.objects.all()
-#         serializer = ManyToManyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [1]},
-#             {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
-#             {'id': 3, 'name': 'target-3', 'sources': [3]}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_many_to_many_create(self):
-#         data = {'id': 4, 'name': 'source-4', 'targets': [1, 3]}
-#         serializer = ManyToManySourceSerializer(data=data)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, data)
-#         self.assertEqual(obj.name, 'source-4')
-
-#         # Ensure source 4 is added, and everything else is as expected
-#         queryset = ManyToManySource.objects.all()
-#         serializer = ManyToManySourceSerializer(queryset, many=True)
-#         self.assertFalse(serializer.fields['targets'].read_only)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'targets': [1]},
-#             {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
-#             {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]},
-#             {'id': 4, 'name': 'source-4', 'targets': [1, 3]},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_reverse_many_to_many_create(self):
-#         data = {'id': 4, 'name': 'target-4', 'sources': [1, 3]}
-#         serializer = ManyToManyTargetSerializer(data=data)
-#         self.assertFalse(serializer.fields['sources'].read_only)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, data)
-#         self.assertEqual(obj.name, 'target-4')
-
-#         # Ensure target 4 is added, and everything else is as expected
-#         queryset = ManyToManyTarget.objects.all()
-#         serializer = ManyToManyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
-#             {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
-#             {'id': 3, 'name': 'target-3', 'sources': [3]},
-#             {'id': 4, 'name': 'target-4', 'sources': [1, 3]}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-
-# class PKForeignKeyTests(TestCase):
-#     def setUp(self):
-#         target = ForeignKeyTarget(name='target-1')
-#         target.save()
-#         new_target = ForeignKeyTarget(name='target-2')
-#         new_target.save()
-#         for idx in range(1, 4):
-#             source = ForeignKeySource(name='source-%d' % idx, target=target)
-#             source.save()
-
-#     def test_foreign_key_retrieve(self):
-#         queryset = ForeignKeySource.objects.all()
-#         serializer = ForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 1},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': 1}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_reverse_foreign_key_retrieve(self):
-#         queryset = ForeignKeyTarget.objects.all()
-#         serializer = ForeignKeyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
-#             {'id': 2, 'name': 'target-2', 'sources': []},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_update(self):
-#         data = {'id': 1, 'name': 'source-1', 'target': 2}
-#         instance = ForeignKeySource.objects.get(pk=1)
-#         serializer = ForeignKeySourceSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         self.assertEqual(serializer.data, data)
-#         serializer.save()
-
-#         # Ensure source 1 is updated, and everything else is as expected
-#         queryset = ForeignKeySource.objects.all()
-#         serializer = ForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 2},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': 1}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_update_incorrect_type(self):
-#         data = {'id': 1, 'name': 'source-1', 'target': 'foo'}
-#         instance = ForeignKeySource.objects.get(pk=1)
-#         serializer = ForeignKeySourceSerializer(instance, data=data)
-#         self.assertFalse(serializer.is_valid())
-#         self.assertEqual(serializer.errors, {'target': ['Incorrect type.  Expected pk value, received %s.' % six.text_type.__name__]})
-
-#     def test_reverse_foreign_key_update(self):
-#         data = {'id': 2, 'name': 'target-2', 'sources': [1, 3]}
-#         instance = ForeignKeyTarget.objects.get(pk=2)
-#         serializer = ForeignKeyTargetSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         # We shouldn't have saved anything to the db yet since save
-#         # hasn't been called.
-#         queryset = ForeignKeyTarget.objects.all()
-#         new_serializer = ForeignKeyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
-#             {'id': 2, 'name': 'target-2', 'sources': []},
-#         ]
-#         self.assertEqual(new_serializer.data, expected)
-
-#         serializer.save()
-#         self.assertEqual(serializer.data, data)
-
-#         # Ensure target 2 is update, and everything else is as expected
-#         queryset = ForeignKeyTarget.objects.all()
-#         serializer = ForeignKeyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [2]},
-#             {'id': 2, 'name': 'target-2', 'sources': [1, 3]},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_create(self):
-#         data = {'id': 4, 'name': 'source-4', 'target': 2}
-#         serializer = ForeignKeySourceSerializer(data=data)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, data)
-#         self.assertEqual(obj.name, 'source-4')
-
-#         # Ensure source 4 is added, and everything else is as expected
-#         queryset = ForeignKeySource.objects.all()
-#         serializer = ForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 1},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': 1},
-#             {'id': 4, 'name': 'source-4', 'target': 2},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_reverse_foreign_key_create(self):
-#         data = {'id': 3, 'name': 'target-3', 'sources': [1, 3]}
-#         serializer = ForeignKeyTargetSerializer(data=data)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, data)
-#         self.assertEqual(obj.name, 'target-3')
-
-#         # Ensure target 3 is added, and everything else is as expected
-#         queryset = ForeignKeyTarget.objects.all()
-#         serializer = ForeignKeyTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'sources': [2]},
-#             {'id': 2, 'name': 'target-2', 'sources': []},
-#             {'id': 3, 'name': 'target-3', 'sources': [1, 3]},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_update_with_invalid_null(self):
-#         data = {'id': 1, 'name': 'source-1', 'target': None}
-#         instance = ForeignKeySource.objects.get(pk=1)
-#         serializer = ForeignKeySourceSerializer(instance, data=data)
-#         self.assertFalse(serializer.is_valid())
-#         self.assertEqual(serializer.errors, {'target': ['This field is required.']})
-
-#     def test_foreign_key_with_empty(self):
-#         """
-#         Regression test for #1072
-
-#         https://github.com/tomchristie/django-rest-framework/issues/1072
-#         """
-#         serializer = NullableForeignKeySourceSerializer()
-#         self.assertEqual(serializer.data['target'], None)
-
-
-# class PKNullableForeignKeyTests(TestCase):
-#     def setUp(self):
-#         target = ForeignKeyTarget(name='target-1')
-#         target.save()
-#         for idx in range(1, 4):
-#             if idx == 3:
-#                 target = None
-#             source = NullableForeignKeySource(name='source-%d' % idx, target=target)
-#             source.save()
-
-#     def test_foreign_key_retrieve_with_null(self):
-#         queryset = NullableForeignKeySource.objects.all()
-#         serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 1},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': None},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_create_with_valid_null(self):
-#         data = {'id': 4, 'name': 'source-4', 'target': None}
-#         serializer = NullableForeignKeySourceSerializer(data=data)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, data)
-#         self.assertEqual(obj.name, 'source-4')
-
-#         # Ensure source 4 is created, and everything else is as expected
-#         queryset = NullableForeignKeySource.objects.all()
-#         serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 1},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': None},
-#             {'id': 4, 'name': 'source-4', 'target': None}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_create_with_valid_emptystring(self):
-#         """
-#         The emptystring should be interpreted as null in the context
-#         of relationships.
-#         """
-#         data = {'id': 4, 'name': 'source-4', 'target': ''}
-#         expected_data = {'id': 4, 'name': 'source-4', 'target': None}
-#         serializer = NullableForeignKeySourceSerializer(data=data)
-#         self.assertTrue(serializer.is_valid())
-#         obj = serializer.save()
-#         self.assertEqual(serializer.data, expected_data)
-#         self.assertEqual(obj.name, 'source-4')
-
-#         # Ensure source 4 is created, and everything else is as expected
-#         queryset = NullableForeignKeySource.objects.all()
-#         serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': 1},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': None},
-#             {'id': 4, 'name': 'source-4', 'target': None}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_update_with_valid_null(self):
-#         data = {'id': 1, 'name': 'source-1', 'target': None}
-#         instance = NullableForeignKeySource.objects.get(pk=1)
-#         serializer = NullableForeignKeySourceSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         self.assertEqual(serializer.data, data)
-#         serializer.save()
-
-#         # Ensure source 1 is updated, and everything else is as expected
-#         queryset = NullableForeignKeySource.objects.all()
-#         serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': None},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': None}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     def test_foreign_key_update_with_valid_emptystring(self):
-#         """
-#         The emptystring should be interpreted as null in the context
-#         of relationships.
-#         """
-#         data = {'id': 1, 'name': 'source-1', 'target': ''}
-#         expected_data = {'id': 1, 'name': 'source-1', 'target': None}
-#         instance = NullableForeignKeySource.objects.get(pk=1)
-#         serializer = NullableForeignKeySourceSerializer(instance, data=data)
-#         self.assertTrue(serializer.is_valid())
-#         self.assertEqual(serializer.data, expected_data)
-#         serializer.save()
-
-#         # Ensure source 1 is updated, and everything else is as expected
-#         queryset = NullableForeignKeySource.objects.all()
-#         serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'source-1', 'target': None},
-#             {'id': 2, 'name': 'source-2', 'target': 1},
-#             {'id': 3, 'name': 'source-3', 'target': None}
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-#     # reverse foreign keys MUST be read_only
-#     # In the general case they do not provide .remove() or .clear()
-#     # and cannot be arbitrarily set.
-
-#     # def test_reverse_foreign_key_update(self):
-#     #     data = {'id': 1, 'name': 'target-1', 'sources': [1]}
-#     #     instance = ForeignKeyTarget.objects.get(pk=1)
-#     #     serializer = ForeignKeyTargetSerializer(instance, data=data)
-#     #     self.assertTrue(serializer.is_valid())
-#     #     self.assertEqual(serializer.data, data)
-#     #     serializer.save()
-
-#     #     # Ensure target 1 is updated, and everything else is as expected
-#     #     queryset = ForeignKeyTarget.objects.all()
-#     #     serializer = ForeignKeyTargetSerializer(queryset, many=True)
-#     #     expected = [
-#     #         {'id': 1, 'name': 'target-1', 'sources': [1]},
-#     #         {'id': 2, 'name': 'target-2', 'sources': []},
-#     #     ]
-#     #     self.assertEqual(serializer.data, expected)
-
-
-# class PKNullableOneToOneTests(TestCase):
-#     def setUp(self):
-#         target = OneToOneTarget(name='target-1')
-#         target.save()
-#         new_target = OneToOneTarget(name='target-2')
-#         new_target.save()
-#         source = NullableOneToOneSource(name='source-1', target=new_target)
-#         source.save()
-
-#     def test_reverse_foreign_key_retrieve_with_null(self):
-#         queryset = OneToOneTarget.objects.all()
-#         serializer = NullableOneToOneTargetSerializer(queryset, many=True)
-#         expected = [
-#             {'id': 1, 'name': 'target-1', 'nullable_source': None},
-#             {'id': 2, 'name': 'target-2', 'nullable_source': 1},
-#         ]
-#         self.assertEqual(serializer.data, expected)
-
-
-# # The below models and tests ensure that serializer fields corresponding
-# # to a ManyToManyField field with a user-specified ``through`` model are
-# # set to read only
+from __future__ import unicode_literals
+from django.test import TestCase
+from django.utils import six
+from rest_framework import serializers
+from tests.models import (
+    ManyToManyTarget, ManyToManySource, ForeignKeyTarget, ForeignKeySource,
+    NullableForeignKeySource, OneToOneTarget, NullableOneToOneSource,
+)
+
+
+# ManyToMany
+class ManyToManyTargetSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ManyToManyTarget
+        fields = ('id', 'name', 'sources')
+
+
+class ManyToManySourceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ManyToManySource
+        fields = ('id', 'name', 'targets')
+
+
+# ForeignKey
+class ForeignKeyTargetSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ForeignKeyTarget
+        fields = ('id', 'name', 'sources')
+
+
+class ForeignKeySourceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ForeignKeySource
+        fields = ('id', 'name', 'target')
+
+
+# Nullable ForeignKey
+class NullableForeignKeySourceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = NullableForeignKeySource
+        fields = ('id', 'name', 'target')
+
+
+# Nullable OneToOne
+class NullableOneToOneTargetSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = OneToOneTarget
+        fields = ('id', 'name', 'nullable_source')
+
+
+# TODO: Add test that .data cannot be accessed prior to .is_valid
+
+class PKManyToManyTests(TestCase):
+    def setUp(self):
+        for idx in range(1, 4):
+            target = ManyToManyTarget(name='target-%d' % idx)
+            target.save()
+            source = ManyToManySource(name='source-%d' % idx)
+            source.save()
+            for target in ManyToManyTarget.objects.all():
+                source.targets.add(target)
+
+    def test_many_to_many_retrieve(self):
+        queryset = ManyToManySource.objects.all()
+        serializer = ManyToManySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'targets': [1]},
+            {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
+            {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_reverse_many_to_many_retrieve(self):
+        queryset = ManyToManyTarget.objects.all()
+        serializer = ManyToManyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
+            {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
+            {'id': 3, 'name': 'target-3', 'sources': [3]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_many_to_many_update(self):
+        data = {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]}
+        instance = ManyToManySource.objects.get(pk=1)
+        serializer = ManyToManySourceSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+        self.assertEqual(serializer.data, data)
+
+        # Ensure source 1 is updated, and everything else is as expected
+        queryset = ManyToManySource.objects.all()
+        serializer = ManyToManySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]},
+            {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
+            {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_reverse_many_to_many_update(self):
+        data = {'id': 1, 'name': 'target-1', 'sources': [1]}
+        instance = ManyToManyTarget.objects.get(pk=1)
+        serializer = ManyToManyTargetSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+        self.assertEqual(serializer.data, data)
+
+        # Ensure target 1 is updated, and everything else is as expected
+        queryset = ManyToManyTarget.objects.all()
+        serializer = ManyToManyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [1]},
+            {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
+            {'id': 3, 'name': 'target-3', 'sources': [3]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_many_to_many_create(self):
+        data = {'id': 4, 'name': 'source-4', 'targets': [1, 3]}
+        serializer = ManyToManySourceSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-4')
+
+        # Ensure source 4 is added, and everything else is as expected
+        queryset = ManyToManySource.objects.all()
+        serializer = ManyToManySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'targets': [1]},
+            {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
+            {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]},
+            {'id': 4, 'name': 'source-4', 'targets': [1, 3]},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_reverse_many_to_many_create(self):
+        data = {'id': 4, 'name': 'target-4', 'sources': [1, 3]}
+        serializer = ManyToManyTargetSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-4')
+
+        # Ensure target 4 is added, and everything else is as expected
+        queryset = ManyToManyTarget.objects.all()
+        serializer = ManyToManyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
+            {'id': 2, 'name': 'target-2', 'sources': [2, 3]},
+            {'id': 3, 'name': 'target-3', 'sources': [3]},
+            {'id': 4, 'name': 'target-4', 'sources': [1, 3]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+
+class PKForeignKeyTests(TestCase):
+    def setUp(self):
+        target = ForeignKeyTarget(name='target-1')
+        target.save()
+        new_target = ForeignKeyTarget(name='target-2')
+        new_target.save()
+        for idx in range(1, 4):
+            source = ForeignKeySource(name='source-%d' % idx, target=target)
+            source.save()
+
+    def test_foreign_key_retrieve(self):
+        queryset = ForeignKeySource.objects.all()
+        serializer = ForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 1},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': 1}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_reverse_foreign_key_retrieve(self):
+        queryset = ForeignKeyTarget.objects.all()
+        serializer = ForeignKeyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
+            {'id': 2, 'name': 'target-2', 'sources': []},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_update(self):
+        data = {'id': 1, 'name': 'source-1', 'target': 2}
+        instance = ForeignKeySource.objects.get(pk=1)
+        serializer = ForeignKeySourceSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+        self.assertEqual(serializer.data, data)
+
+        # Ensure source 1 is updated, and everything else is as expected
+        queryset = ForeignKeySource.objects.all()
+        serializer = ForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 2},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': 1}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_update_incorrect_type(self):
+        data = {'id': 1, 'name': 'source-1', 'target': 'foo'}
+        instance = ForeignKeySource.objects.get(pk=1)
+        serializer = ForeignKeySourceSerializer(instance, data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(serializer.errors, {'target': ['Incorrect type. Expected pk value, received %s.' % six.text_type.__name__]})
+
+    def test_reverse_foreign_key_update(self):
+        data = {'id': 2, 'name': 'target-2', 'sources': [1, 3]}
+        instance = ForeignKeyTarget.objects.get(pk=2)
+        serializer = ForeignKeyTargetSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        # We shouldn't have saved anything to the db yet since save
+        # hasn't been called.
+        queryset = ForeignKeyTarget.objects.all()
+        new_serializer = ForeignKeyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [1, 2, 3]},
+            {'id': 2, 'name': 'target-2', 'sources': []},
+        ]
+        self.assertEqual(new_serializer.data, expected)
+
+        serializer.save()
+        self.assertEqual(serializer.data, data)
+
+        # Ensure target 2 is update, and everything else is as expected
+        queryset = ForeignKeyTarget.objects.all()
+        serializer = ForeignKeyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [2]},
+            {'id': 2, 'name': 'target-2', 'sources': [1, 3]},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_create(self):
+        data = {'id': 4, 'name': 'source-4', 'target': 2}
+        serializer = ForeignKeySourceSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-4')
+
+        # Ensure source 4 is added, and everything else is as expected
+        queryset = ForeignKeySource.objects.all()
+        serializer = ForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 1},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': 1},
+            {'id': 4, 'name': 'source-4', 'target': 2},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_reverse_foreign_key_create(self):
+        data = {'id': 3, 'name': 'target-3', 'sources': [1, 3]}
+        serializer = ForeignKeyTargetSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-3')
+
+        # Ensure target 3 is added, and everything else is as expected
+        queryset = ForeignKeyTarget.objects.all()
+        serializer = ForeignKeyTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [2]},
+            {'id': 2, 'name': 'target-2', 'sources': []},
+            {'id': 3, 'name': 'target-3', 'sources': [1, 3]},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_update_with_invalid_null(self):
+        data = {'id': 1, 'name': 'source-1', 'target': None}
+        instance = ForeignKeySource.objects.get(pk=1)
+        serializer = ForeignKeySourceSerializer(instance, data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(serializer.errors, {'target': ['This field may not be null.']})
+
+    def test_foreign_key_with_empty(self):
+        """
+        Regression test for #1072
+
+        https://github.com/tomchristie/django-rest-framework/issues/1072
+        """
+        serializer = NullableForeignKeySourceSerializer()
+        self.assertEqual(serializer.data['target'], None)
+
+
+class PKNullableForeignKeyTests(TestCase):
+    def setUp(self):
+        target = ForeignKeyTarget(name='target-1')
+        target.save()
+        for idx in range(1, 4):
+            if idx == 3:
+                target = None
+            source = NullableForeignKeySource(name='source-%d' % idx, target=target)
+            source.save()
+
+    def test_foreign_key_retrieve_with_null(self):
+        queryset = NullableForeignKeySource.objects.all()
+        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 1},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': None},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_create_with_valid_null(self):
+        data = {'id': 4, 'name': 'source-4', 'target': None}
+        serializer = NullableForeignKeySourceSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-4')
+
+        # Ensure source 4 is created, and everything else is as expected
+        queryset = NullableForeignKeySource.objects.all()
+        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 1},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': None},
+            {'id': 4, 'name': 'source-4', 'target': None}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_create_with_valid_emptystring(self):
+        """
+        The emptystring should be interpreted as null in the context
+        of relationships.
+        """
+        data = {'id': 4, 'name': 'source-4', 'target': ''}
+        expected_data = {'id': 4, 'name': 'source-4', 'target': None}
+        serializer = NullableForeignKeySourceSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, expected_data)
+        self.assertEqual(obj.name, 'source-4')
+
+        # Ensure source 4 is created, and everything else is as expected
+        queryset = NullableForeignKeySource.objects.all()
+        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': 1},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': None},
+            {'id': 4, 'name': 'source-4', 'target': None}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_update_with_valid_null(self):
+        data = {'id': 1, 'name': 'source-1', 'target': None}
+        instance = NullableForeignKeySource.objects.get(pk=1)
+        serializer = NullableForeignKeySourceSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+        self.assertEqual(serializer.data, data)
+
+        # Ensure source 1 is updated, and everything else is as expected
+        queryset = NullableForeignKeySource.objects.all()
+        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': None},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': None}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_foreign_key_update_with_valid_emptystring(self):
+        """
+        The emptystring should be interpreted as null in the context
+        of relationships.
+        """
+        data = {'id': 1, 'name': 'source-1', 'target': ''}
+        expected_data = {'id': 1, 'name': 'source-1', 'target': None}
+        instance = NullableForeignKeySource.objects.get(pk=1)
+        serializer = NullableForeignKeySourceSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+        self.assertEqual(serializer.data, expected_data)
+
+        # Ensure source 1 is updated, and everything else is as expected
+        queryset = NullableForeignKeySource.objects.all()
+        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': None},
+            {'id': 2, 'name': 'source-2', 'target': 1},
+            {'id': 3, 'name': 'source-3', 'target': None}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    # reverse foreign keys MUST be read_only
+    # In the general case they do not provide .remove() or .clear()
+    # and cannot be arbitrarily set.
+
+    # def test_reverse_foreign_key_update(self):
+    #     data = {'id': 1, 'name': 'target-1', 'sources': [1]}
+    #     instance = ForeignKeyTarget.objects.get(pk=1)
+    #     serializer = ForeignKeyTargetSerializer(instance, data=data)
+    #     self.assertTrue(serializer.is_valid())
+    #     self.assertEqual(serializer.data, data)
+    #     serializer.save()
+
+    #     # Ensure target 1 is updated, and everything else is as expected
+    #     queryset = ForeignKeyTarget.objects.all()
+    #     serializer = ForeignKeyTargetSerializer(queryset, many=True)
+    #     expected = [
+    #         {'id': 1, 'name': 'target-1', 'sources': [1]},
+    #         {'id': 2, 'name': 'target-2', 'sources': []},
+    #     ]
+    #     self.assertEqual(serializer.data, expected)
+
+
+class PKNullableOneToOneTests(TestCase):
+    def setUp(self):
+        target = OneToOneTarget(name='target-1')
+        target.save()
+        new_target = OneToOneTarget(name='target-2')
+        new_target.save()
+        source = NullableOneToOneSource(name='source-1', target=new_target)
+        source.save()
+
+    def test_reverse_foreign_key_retrieve_with_null(self):
+        queryset = OneToOneTarget.objects.all()
+        serializer = NullableOneToOneTargetSerializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'nullable_source': None},
+            {'id': 2, 'name': 'target-2', 'nullable_source': 1},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+
+# The below models and tests ensure that serializer fields corresponding
+# to a ManyToManyField field with a user-specified ``through`` model are
+# set to read only
 
 
 # class ManyToManyThroughTarget(models.Model):
@@ -481,7 +478,6 @@
 #     def test_many_to_many_create(self):
 #         data = {'id': 2, 'name': 'source-2', 'targets': [self.target.pk]}
 #         serializer = ManyToManyThroughSourceSerializer(data=data)
-#         self.assertTrue(serializer.fields['targets'].read_only)
 #         self.assertTrue(serializer.is_valid())
 #         obj = serializer.save()
 #         self.assertEqual(obj.name, 'source-2')
@@ -490,9 +486,7 @@
 #     def test_many_to_many_reverse_create(self):
 #         data = {'id': 2, 'name': 'target-2', 'sources': [self.source.pk]}
 #         serializer = ManyToManyThroughTargetSerializer(data=data)
-#         self.assertTrue(serializer.fields['sources'].read_only)
 #         self.assertTrue(serializer.is_valid())
-#         serializer.save()
 #         obj = serializer.save()
 #         self.assertEqual(obj.name, 'target-2')
 #         self.assertEqual(obj.sources.count(), 0)