Merge pull request #1551 from MattFisher/syncdata-natural-keys

Failing test and fixture for syncdata with natural keys

tests/management/commands/fixtures/fixture_with_constraint.json

@@ -0,0 +1,9 @@
+[
+   {
+      "pk" : 2,
+      "fields" : {
+         "global_id" : "must be unique"
+      },
+      "model" : "testapp.UniqueTestAppModel"
+   }
+]

tests/management/commands/fixtures/fixture_with_natural_key.json

@@ -0,0 +1,30 @@
+[
+  {
+    "model": "auth.group",
+    "pk": 1,
+    "fields": {
+      "name": "teachers",
+      "permissions": []
+    }
+  },
+  {
+    "model": "auth.user",
+    "pk": 1,
+    "fields": {
+      "password": "",
+      "last_login": null,
+      "is_superuser": false,
+      "username": "staff",
+      "first_name": "",
+      "last_name": "",
+      "email": "",
+      "is_staff": true,
+      "is_active": true,
+      "date_joined": "2017-05-01T03:49:00.823Z",
+      "groups": [
+        ["teachers"]
+      ],
+      "user_permissions": []
+    }
+  }
+]

tests/management/commands/test_syncdata.py

@@ -2,14 +2,16 @@
 import os
 
 import pytest
-from django.contrib.auth.models import User
+from django.contrib.auth.models import User, Group
 from django.core.management import call_command, CommandError
 from django.test import TestCase
 from django.test.utils import override_settings
 from io import StringIO
 
 from unittest.mock import patch
 
+from tests.testapp.models import UniqueTestAppModel
+
 
 TEST_FIXTURE_DIR = os.path.join(os.path.dirname(__file__), 'fixtures')
 
@@ -72,3 +74,15 @@ def test_should_delete_old_objects_and_load_data_from_json_fixture(self, m_stdou
         self.assertTrue(User.objects.filter(username='jdoe').exists())
         self.assertEqual(User.objects.count(), 1)
         self.assertIn('Installed 1 object from 1 fixture', m_stdout.getvalue())
+
+    def test_should_handle_natural_keys_in_fixtures(self):
+        call_command('syncdata', 'fixture_with_natural_key.json')
+
+        self.assertTrue(Group.objects.filter(name='teachers').exists())
+        self.assertTrue(User.objects.filter(username='staff').exists())
+
+    def test_should_resolve_transient_constraint_conflicts_in_fixtures(self):
+        UniqueTestAppModel.objects.create(pk=1, global_id="must be unique")
+        # This fixture creates a second instance with a different pk but the same global_id
+        call_command('syncdata', 'fixture_with_constraint.json')
+        self.assertEqual(UniqueTestAppModel.objects.count(), 1)