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

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)