Hotfix: make news audience migration non-atomic

news/migrations/0010_news_audience_newscomment.py

@@ -26,6 +26,8 @@ def set_existing_news_audiences(apps, schema_editor):
 
 
 class Migration(migrations.Migration):
+    atomic = False
+
     dependencies = [
         migrations.swappable_dependency(settings.AUTH_USER_MODEL),
         ("news", "0009_news_pin"),
@@ -53,9 +55,7 @@ class Migration(migrations.Migration):
         migrations.AddConstraint(
             model_name="news",
             constraint=models.CheckConstraint(
-                check=models.Q(
-                    audience__in=("platform", "program_participants")
-                ),
+                check=models.Q(audience__in=("platform", "program_participants")),
                 name="news_valid_audience",
             ),
         ),

news/tests/test_news_migration_0010.py

@@ -0,0 +1,81 @@
+from importlib import import_module
+import unittest
+
+from django.db import connection, migrations
+from django.db.migrations.executor import MigrationExecutor
+from django.test import SimpleTestCase, TransactionTestCase
+
+
+class NewsMigration0010MetadataTests(SimpleTestCase):
+    def test_migration_is_non_atomic(self):
+        migration = import_module("news.migrations.0010_news_audience_newscomment")
+
+        self.assertIs(migration.Migration.atomic, False)
+
+    def test_runpython_does_not_reintroduce_atomic_transaction(self):
+        migration = import_module("news.migrations.0010_news_audience_newscomment")
+        run_python_operations = [
+            operation
+            for operation in migration.Migration.operations
+            if isinstance(operation, migrations.RunPython)
+        ]
+
+        self.assertEqual(len(run_python_operations), 1)
+        self.assertIsNone(run_python_operations[0].atomic)
+
+
+@unittest.skipUnless(
+    connection.vendor == "postgresql",
+    "PostgreSQL-only regression for pending trigger events during migration 0010.",
+)
+class NewsMigration0010PostgreSQLTests(TransactionTestCase):
+    migrate_from = [("news", "0009_news_pin")]
+    migrate_to = [("news", "0010_news_audience_newscomment")]
+
+    def setUp(self):
+        super().setUp()
+        self.executor = MigrationExecutor(connection)
+        self.executor.migrate(self.migrate_from)
+        self.apps = self.executor.loader.project_state(self.migrate_from).apps
+
+    def tearDown(self):
+        self.executor.loader.build_graph()
+        self.executor.migrate(self.migrate_to)
+        super().tearDown()
+
+    def test_applies_after_updating_existing_news_rows(self):
+        ContentType = self.apps.get_model("contenttypes", "ContentType")
+        News = self.apps.get_model("news", "News")
+        project_content_type, _ = ContentType.objects.get_or_create(
+            app_label="projects",
+            model="project",
+        )
+        program_content_type, _ = ContentType.objects.get_or_create(
+            app_label="partner_programs",
+            model="partnerprogram",
+        )
+
+        News.objects.create(
+            content_type=project_content_type,
+            object_id=1,
+            text="Project news",
+        )
+        News.objects.create(
+            content_type=program_content_type,
+            object_id=1,
+            text="Program news",
+        )
+
+        self.executor.loader.build_graph()
+        self.executor.migrate(self.migrate_to)
+        migrated_apps = self.executor.loader.project_state(self.migrate_to).apps
+        MigratedNews = migrated_apps.get_model("news", "News")
+
+        self.assertEqual(
+            MigratedNews.objects.get(content_type_id=project_content_type.id).audience,
+            "platform",
+        )
+        self.assertEqual(
+            MigratedNews.objects.get(content_type_id=program_content_type.id).audience,
+            "program_participants",
+        )