Fix ModelViewSet Nested bug (#65)

* Add todo repro app
* Add explicit test against model named "Nested"
* Force serializers named NestedSerializer to be output as inline models
* Allow ref_name to rescue a NestedSerializer
* Add tests and documentation

testproj/todo/migrations/0001_initial.py

@@ -0,0 +1,40 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11 on 2018-02-21 23:26
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Todo',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(max_length=50)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='TodoAnother',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(max_length=50)),
+                ('todo', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='todo.Todo')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='TodoYetAnother',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(max_length=50)),
+                ('todo', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='todo.TodoAnother')),
+            ],
+        ),
+    ]

testproj/todo/models.py

@@ -0,0 +1,15 @@
+from django.db import models
+
+
+class Todo(models.Model):
+    title = models.CharField(max_length=50)
+
+
+class TodoAnother(models.Model):
+    todo = models.ForeignKey(Todo, on_delete=models.CASCADE)
+    title = models.CharField(max_length=50)
+
+
+class TodoYetAnother(models.Model):
+    todo = models.ForeignKey(TodoAnother, on_delete=models.CASCADE)
+    title = models.CharField(max_length=50)

testproj/todo/serializer.py

@@ -0,0 +1,24 @@
+from rest_framework import serializers
+
+from .models import Todo, TodoAnother, TodoYetAnother
+
+
+class TodoSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Todo
+        fields = ('title',)
+
+
+class TodoAnotherSerializer(serializers.ModelSerializer):
+    todo = TodoSerializer()
+
+    class Meta:
+        model = TodoAnother
+        fields = ('title', 'todo')
+
+
+class TodoYetAnotherSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = TodoYetAnother
+        fields = ('title', 'todo')
+        depth = 2

testproj/todo/urls.py

@@ -0,0 +1,10 @@
+from rest_framework import routers
+
+from todo import views
+
+router = routers.DefaultRouter()
+router.register(r'', views.TodoViewSet)
+router.register(r'another', views.TodoAnotherViewSet)
+router.register(r'yetanother', views.TodoYetAnotherViewSet)
+
+urlpatterns = router.urls

testproj/todo/views.py

@@ -0,0 +1,19 @@
+from rest_framework import viewsets
+
+from .models import Todo, TodoAnother, TodoYetAnother
+from .serializer import TodoAnotherSerializer, TodoSerializer, TodoYetAnotherSerializer
+
+
+class TodoViewSet(viewsets.ReadOnlyModelViewSet):
+    queryset = Todo.objects.all()
+    serializer_class = TodoSerializer
+
+
+class TodoAnotherViewSet(viewsets.ReadOnlyModelViewSet):
+    queryset = TodoAnother.objects.all()
+    serializer_class = TodoAnotherSerializer
+
+
+class TodoYetAnotherViewSet(viewsets.ReadOnlyModelViewSet):
+    queryset = TodoYetAnother.objects.all()
+    serializer_class = TodoYetAnotherSerializer