Fixed #26291 -- Allowed loaddata to handle forward references in natural_key fixtures.

6 files changed, 193 insertions, 2 deletions

diff --git a/tests/fixtures/fixtures/forward_reference_fk.json b/tests/fixtures/fixtures/forward_reference_fk.json
new file mode 100644
index 0000000000..d3122c8823
--- /dev/null
+++ b/tests/fixtures/fixtures/forward_reference_fk.json
@@ -0,0 +1,20 @@
+[
+  {
+    "model": "fixtures.naturalkeything",
+    "fields": {
+      "key": "t1",
+      "other_thing": [
+        "t2"
+      ]
+    }
+  },
+  {
+    "model": "fixtures.naturalkeything",
+    "fields": {
+      "key": "t2",
+      "other_thing": [
+        "t1"
+      ]
+    }
+  }
+]
diff --git a/tests/fixtures/fixtures/forward_reference_m2m.json b/tests/fixtures/fixtures/forward_reference_m2m.json
new file mode 100644
index 0000000000..9e0f18e294
--- /dev/null
+++ b/tests/fixtures/fixtures/forward_reference_m2m.json
@@ -0,0 +1,23 @@
+[
+  {
+    "model": "fixtures.naturalkeything",
+    "fields": {
+      "key": "t1",
+      "other_things": [
+        ["t2"], ["t3"]
+      ]
+    }
+  },
+  {
+    "model": "fixtures.naturalkeything",
+    "fields": {
+      "key": "t2"
+    }
+  },
+  {
+    "model": "fixtures.naturalkeything",
+    "fields": {
+      "key": "t3"
+    }
+  }
+]
diff --git a/tests/fixtures/models.py b/tests/fixtures/models.py
index 07ef1587d9..be6674fa61 100644
--- a/tests/fixtures/models.py
+++ b/tests/fixtures/models.py
@@ -116,3 +116,21 @@ class Book(models.Model):
 
 class PrimaryKeyUUIDModel(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4)
+
+
+class NaturalKeyThing(models.Model):
+    key = models.CharField(max_length=100)
+    other_thing = models.ForeignKey('NaturalKeyThing', on_delete=models.CASCADE, null=True)
+    other_things = models.ManyToManyField('NaturalKeyThing', related_name='thing_m2m_set')
+
+    class Manager(models.Manager):
+        def get_by_natural_key(self, key):
+            return self.get(key=key)
+
+    objects = Manager()
+
+    def natural_key(self):
+        return (self.key,)
+
+    def __str__(self):
+        return self.key
diff --git a/tests/fixtures/tests.py b/tests/fixtures/tests.py
index d48062f8dd..37b21fa296 100644
--- a/tests/fixtures/tests.py
+++ b/tests/fixtures/tests.py
@@ -17,7 +17,8 @@ from django.db import IntegrityError, connection
 from django.test import TestCase, TransactionTestCase, skipUnlessDBFeature
 
 from .models import (
-    Article, Category, PrimaryKeyUUIDModel, ProxySpy, Spy, Tag, Visa,
+    Article, Category, NaturalKeyThing, PrimaryKeyUUIDModel, ProxySpy, Spy,
+    Tag, Visa,
 )
 
 
@@ -780,3 +781,21 @@ class FixtureTransactionTests(DumpDataAssertMixin, TransactionTestCase):
             '<Article: Time to reform copyright>',
             '<Article: Poker has no place on ESPN>',
         ])
+
+
+class ForwardReferenceTests(TestCase):
+    def test_forward_reference_fk(self):
+        management.call_command('loaddata', 'forward_reference_fk.json', verbosity=0)
+        self.assertEqual(NaturalKeyThing.objects.count(), 2)
+        t1, t2 = NaturalKeyThing.objects.all()
+        self.assertEqual(t1.other_thing, t2)
+        self.assertEqual(t2.other_thing, t1)
+
+    def test_forward_reference_m2m(self):
+        management.call_command('loaddata', 'forward_reference_m2m.json', verbosity=0)
+        self.assertEqual(NaturalKeyThing.objects.count(), 3)
+        t1 = NaturalKeyThing.objects.get_by_natural_key('t1')
+        self.assertQuerysetEqual(
+            t1.other_things.order_by('key'),
+            ['<NaturalKeyThing: t2>', '<NaturalKeyThing: t3>']
+        )
diff --git a/tests/serializers/models/natural.py b/tests/serializers/models/natural.py
index b50956692e..cd24b67f0a 100644
--- a/tests/serializers/models/natural.py
+++ b/tests/serializers/models/natural.py
@@ -19,3 +19,21 @@ class NaturalKeyAnchor(models.Model):
 
 class FKDataNaturalKey(models.Model):
     data = models.ForeignKey(NaturalKeyAnchor, models.SET_NULL, null=True)
+
+
+class NaturalKeyThing(models.Model):
+    key = models.CharField(max_length=100)
+    other_thing = models.ForeignKey('NaturalKeyThing', on_delete=models.CASCADE, null=True)
+    other_things = models.ManyToManyField('NaturalKeyThing', related_name='thing_m2m_set')
+
+    class Manager(models.Manager):
+        def get_by_natural_key(self, key):
+            return self.get(key=key)
+
+    objects = Manager()
+
+    def natural_key(self):
+        return (self.key,)
+
+    def __str__(self):
+        return self.key
diff --git a/tests/serializers/test_natural.py b/tests/serializers/test_natural.py
index 776f554a1c..7e9e9382da 100644
--- a/tests/serializers/test_natural.py
+++ b/tests/serializers/test_natural.py
@@ -2,7 +2,7 @@ from django.core import serializers
 from django.db import connection
 from django.test import TestCase
 
-from .models import Child, FKDataNaturalKey, NaturalKeyAnchor
+from .models import Child, FKDataNaturalKey, NaturalKeyAnchor, NaturalKeyThing
 from .tests import register_tests
 
 
@@ -93,7 +93,100 @@ def natural_pk_mti_test(self, format):
         self.assertEqual(child.child_data, child.parent_data)
 
 
+def forward_ref_fk_test(self, format):
+    t1 = NaturalKeyThing.objects.create(key='t1')
+    t2 = NaturalKeyThing.objects.create(key='t2', other_thing=t1)
+    t1.other_thing = t2
+    t1.save()
+    string_data = serializers.serialize(
+        format, [t1, t2], use_natural_primary_keys=True,
+        use_natural_foreign_keys=True,
+    )
+    NaturalKeyThing.objects.all().delete()
+    objs_with_deferred_fields = []
+    for obj in serializers.deserialize(format, string_data, handle_forward_references=True):
+        obj.save()
+        if obj.deferred_fields:
+            objs_with_deferred_fields.append(obj)
+    for obj in objs_with_deferred_fields:
+        obj.save_deferred_fields()
+    t1 = NaturalKeyThing.objects.get(key='t1')
+    t2 = NaturalKeyThing.objects.get(key='t2')
+    self.assertEqual(t1.other_thing, t2)
+    self.assertEqual(t2.other_thing, t1)
+
+
+def forward_ref_fk_with_error_test(self, format):
+    t1 = NaturalKeyThing.objects.create(key='t1')
+    t2 = NaturalKeyThing.objects.create(key='t2', other_thing=t1)
+    t1.other_thing = t2
+    t1.save()
+    string_data = serializers.serialize(
+        format, [t1], use_natural_primary_keys=True,
+        use_natural_foreign_keys=True,
+    )
+    NaturalKeyThing.objects.all().delete()
+    objs_with_deferred_fields = []
+    for obj in serializers.deserialize(format, string_data, handle_forward_references=True):
+        obj.save()
+        if obj.deferred_fields:
+            objs_with_deferred_fields.append(obj)
+    obj = objs_with_deferred_fields[0]
+    msg = 'NaturalKeyThing matching query does not exist'
+    with self.assertRaisesMessage(serializers.base.DeserializationError, msg):
+        obj.save_deferred_fields()
+
+
+def forward_ref_m2m_test(self, format):
+    t1 = NaturalKeyThing.objects.create(key='t1')
+    t2 = NaturalKeyThing.objects.create(key='t2')
+    t3 = NaturalKeyThing.objects.create(key='t3')
+    t1.other_things.set([t2, t3])
+    string_data = serializers.serialize(
+        format, [t1, t2, t3], use_natural_primary_keys=True,
+        use_natural_foreign_keys=True,
+    )
+    NaturalKeyThing.objects.all().delete()
+    objs_with_deferred_fields = []
+    for obj in serializers.deserialize(format, string_data, handle_forward_references=True):
+        obj.save()
+        if obj.deferred_fields:
+            objs_with_deferred_fields.append(obj)
+    for obj in objs_with_deferred_fields:
+        obj.save_deferred_fields()
+    t1 = NaturalKeyThing.objects.get(key='t1')
+    t2 = NaturalKeyThing.objects.get(key='t2')
+    t3 = NaturalKeyThing.objects.get(key='t3')
+    self.assertCountEqual(t1.other_things.all(), [t2, t3])
+
+
+def forward_ref_m2m_with_error_test(self, format):
+    t1 = NaturalKeyThing.objects.create(key='t1')
+    t2 = NaturalKeyThing.objects.create(key='t2')
+    t3 = NaturalKeyThing.objects.create(key='t3')
+    t1.other_things.set([t2, t3])
+    t1.save()
+    string_data = serializers.serialize(
+        format, [t1, t2], use_natural_primary_keys=True,
+        use_natural_foreign_keys=True,
+    )
+    NaturalKeyThing.objects.all().delete()
+    objs_with_deferred_fields = []
+    for obj in serializers.deserialize(format, string_data, handle_forward_references=True):
+        obj.save()
+        if obj.deferred_fields:
+            objs_with_deferred_fields.append(obj)
+    obj = objs_with_deferred_fields[0]
+    msg = 'NaturalKeyThing matching query does not exist'
+    with self.assertRaisesMessage(serializers.base.DeserializationError, msg):
+        obj.save_deferred_fields()
+
+
 # Dynamically register tests for each serializer
 register_tests(NaturalKeySerializerTests, 'test_%s_natural_key_serializer', natural_key_serializer_test)
 register_tests(NaturalKeySerializerTests, 'test_%s_serializer_natural_keys', natural_key_test)
 register_tests(NaturalKeySerializerTests, 'test_%s_serializer_natural_pks_mti', natural_pk_mti_test)
+register_tests(NaturalKeySerializerTests, 'test_%s_forward_references_fks', forward_ref_fk_test)
+register_tests(NaturalKeySerializerTests, 'test_%s_forward_references_fk_errors', forward_ref_fk_with_error_test)
+register_tests(NaturalKeySerializerTests, 'test_%s_forward_references_m2ms', forward_ref_m2m_test)
+register_tests(NaturalKeySerializerTests, 'test_%s_forward_references_m2m_errors', forward_ref_m2m_with_error_test)