Rewrite durable task lifecycle, gallery indexing and subscription publication

scripts/test_user_links.py

@@ -0,0 +1,55 @@
+import importlib.util
+from pathlib import Path
+import sqlite3
+import tempfile
+import unittest
+
+spec = importlib.util.spec_from_file_location("migration", Path(__file__).with_name("migrate_user_links.py"))
+migration = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(migration)
+
+
+class MigrationTest(unittest.TestCase):
+    def test_dry_run_idempotent_migration_and_rename(self):
+        with tempfile.TemporaryDirectory() as temporary:
+            path = Path(temporary) / "test.db"
+            with sqlite3.connect(path) as db:
+                db.executescript("""
+                    CREATE TABLE User(id INTEGER PRIMARY KEY, username TEXT);
+                    CREATE TABLE sub_bind(key TEXT PRIMARY KEY, user TEXT, subscription_account_id INTEGER);
+                    CREATE TABLE sub_update_record(id INTEGER PRIMARY KEY, user TEXT, location TEXT);
+                    INSERT INTO User VALUES(1,'old-name');
+                    INSERT INTO sub_bind VALUES('example-key','old-name',2);
+                    INSERT INTO sub_update_record VALUES(10,'old-name','unknown');
+                    INSERT INTO sub_update_record VALUES(11,'old-name','unknown');
+                """)
+            before = path.read_bytes()
+            self.assertEqual(2, len(migration.migrate(path)["schema_changes"]))
+            self.assertEqual(before, path.read_bytes())
+            self.assertEqual(0, migration.migrate(path, True)["unresolved_bindings"])
+            self.assertEqual([], migration.migrate(path, True)["schema_changes"])
+            with sqlite3.connect(path) as db:
+                db.execute("update User set username='new-name' where id=1")
+                self.assertEqual((1,), db.execute("select user_id from sub_bind").fetchone())
+                # A slow first lookup must not overwrite the second request's row.
+                db.execute("update sub_update_record set location='first-location' where id=10")
+                self.assertEqual(("unknown",), db.execute("select location from sub_update_record where id=11").fetchone())
+
+    def test_ambiguous_names_fail_without_modifying_database(self):
+        with tempfile.TemporaryDirectory() as temporary:
+            path = Path(temporary) / "test.db"
+            with sqlite3.connect(path) as db:
+                db.executescript("""
+                    CREATE TABLE User(id INTEGER PRIMARY KEY, username TEXT);
+                    CREATE TABLE sub_bind(user TEXT);
+                    CREATE TABLE sub_update_record(user TEXT);
+                    INSERT INTO User VALUES(1,'same'),(2,'same');
+                """)
+            before = path.read_bytes()
+            with self.assertRaises(ValueError):
+                migration.migrate(path, True)
+            self.assertEqual(before, path.read_bytes())
+
+
+if __name__ == "__main__":
+    unittest.main()