Initial PK relationship tests

rest_framework/tests/pk_relations.py

+from django.db import models
+from django.test import TestCase
+from rest_framework import serializers
+
+
+class Target(models.Model):
+    name = models.CharField(max_length=100)
+
+
+class Source(models.Model):
+    name = models.CharField(max_length=100)
+    targets = models.ManyToManyField(Target, related_name='sources')
+
+
+class TargetSerializer(serializers.ModelSerializer):
+    sources = serializers.ManyPrimaryKeyRelatedField()
+
+    class Meta:
+        fields = ('id', 'name', 'sources')
+        model = Target
+
+
+class SourceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Source
+
+
+# TODO: Add test that .data cannot be accessed prior to .is_valid
+
+class PrimaryKeyManyToManyTests(TestCase):
+    def setUp(self):
+        for idx in range(1, 4):
+            target = Target(name='target-%d' % idx)
+            target.save()
+            source = Source(name='source-%d' % idx)
+            source.save()
+            for target in Target.objects.all():
+                source.targets.add(target)
+
+    def test_many_to_many_retrieve(self):
+        serializer = SourceSerializer(instance=Source.objects.all())
+        expected = [
+                {'id': 1, 'name': u'source-1', 'targets': [1]},
+                {'id': 2, 'name': u'source-2', 'targets': [1, 2]},
+                {'id': 3, 'name': u'source-3', 'targets': [1, 2, 3]}
+        ]
+        self.assertEquals(serializer.data, expected)
+
+    def test_reverse_many_to_many_retrieve(self):
+        serializer = TargetSerializer(instance=Target.objects.all())
+        expected = [
+            {'id': 1, 'name': u'target-1', 'sources': [1, 2, 3]},
+            {'id': 2, 'name': u'target-2', 'sources': [2, 3]},
+            {'id': 3, 'name': u'target-3', 'sources': [3]}
+        ]
+        self.assertEquals(serializer.data, expected)
+
+    def test_many_to_many_update(self):
+        data = {'id': 1, 'name': u'source-1', 'targets': [1, 2, 3]}
+        serializer = SourceSerializer(data, instance=Source.objects.get(pk=1))
+        self.assertTrue(serializer.is_valid())
+        self.assertEquals(serializer.data, data)
+
+        # Ensure source 1 is updated, and everything else is as expected
+        serializer = SourceSerializer(instance=Source.objects.all())
+        expected = [
+                {'id': 1, 'name': u'source-1', 'targets': [1, 2, 3]},
+                {'id': 2, 'name': u'source-2', 'targets': [1, 2]},
+                {'id': 3, 'name': u'source-3', 'targets': [1, 2, 3]}
+        ]
+        self.assertEquals(serializer.data, expected)
+
+    def test_reverse_many_to_many_update(self):
+        data = {'id': 1, 'name': u'target-0', 'sources': [1]}
+        serializer = TargetSerializer(data, instance=Target.objects.get(pk=1))
+        self.assertTrue(serializer.is_valid())
+        self.assertEquals(serializer.data, data)
+
+        # Ensure target 1 is updated, and everything else is as expected
+        serializer = TargetSerializer(instance=Target.objects.all())
+        expected = [
+            {'id': 1, 'name': u'target-1', 'sources': [1]},
+            {'id': 2, 'name': u'target-2', 'sources': [2, 3]},
+            {'id': 3, 'name': u'target-3', 'sources': [3]}
+        ]
+        self.assertEquals(serializer.data, expected)