Test showing nested serializer model assumption

rest_framework/tests/models.py

@@ -1,4 +1,7 @@
 from __future__ import unicode_literals
+
+import json
+
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from rest_framework import serializers
@@ -15,6 +18,20 @@ class CustomField(models.CharField):
         super(CustomField, self).__init__(*args, **kwargs)
 
 
+class BasicJSONField(models.Field):
+    def to_python(self, value):
+        try:
+            return json.loads(value)
+        except:
+            return value
+
+    def get_db_prep_value(self, value, *args, **kwargs):
+        return json.dumps(value)
+
+    def get_internal_type(self):
+        return 'TextField'
+
+
 class RESTFrameworkModel(models.Model):
     """
     Base for test models that sets app_label, so they play nicely.
@@ -164,6 +181,12 @@ class NullableOneToOneSource(RESTFrameworkModel):
                                   related_name='nullable_source')
 
 
+class Project(RESTFrameworkModel):
+    """A model with a JSON field to test nested serializers."""
+    name = models.CharField(max_length=100)
+    milestones = BasicJSONField()
+
+
 # Serializer used to test BasicModel
 class BasicModelSerializer(serializers.ModelSerializer):
     class Meta:

rest_framework/tests/test_serializer_nested.py

@@ -247,6 +247,42 @@ class WritableNestedSerializerObjectTests(TestCase):
         self.assertEqual(serializer.object, expected_object)
 
 
+class WritableNestedSerializerFieldTests(TestCase):
+    """
+    Nested serializers should not be assumed to reference nested models.
+
+    In this case, MilestoneSerializer is used to control the data going into
+    a JSON field, "milestones".
+    """
+    def setUp(self):
+        class MilestoneSerializer(serializers.Serializer):
+            name = serializers.CharField()
+
+        class ProjectSerializer(serializers.ModelSerializer):
+            name = serializers.CharField()
+            milestones = MilestoneSerializer(many=True)
+
+            class Meta:
+                model = models.Project
+
+        self.ProjectSerializer = ProjectSerializer
+
+    def test_deserialize(self):
+        data = {
+            'name': 'The Awesome API Project',
+            'milestones': [
+                {'name': 'Prototype'},
+                {'name': 'Minumum viable product'},
+                {'name': 'World domination'},
+            ],
+        }
+        expected_object = models.Project(**data)
+        serializer = self.ProjectSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(obj.milestones, expected_object.milestones)
+
+
 class ForeignKeyNestedSerializerUpdateTests(TestCase):
     def setUp(self):
         class Artist(object):