feat(poll): reorder options without invalidating answers

tests/test_response_editing.py

@@ -5,7 +5,12 @@ import unittest
 from sqlalchemy import create_engine
 from sqlalchemy.orm import Session, sessionmaker
 
-from govoplan_core.core.poll import PollCapabilityError, PollOptionUpdateCommand, PollSchedulingProvider
+from govoplan_core.core.poll import (
+    PollCapabilityError,
+    PollOptionOrderCommand,
+    PollOptionUpdateCommand,
+    PollSchedulingProvider,
+)
 from govoplan_core.db.base import Base
 from govoplan_poll.backend.capabilities import SqlPollSchedulingProvider
 from govoplan_poll.backend.db.models import Poll, PollOption, PollResponse
@@ -174,6 +179,61 @@ class PollResponseEditingTests(unittest.TestCase):
         self.assertEqual(poll.options[0].label, "Monday")
         self.assertEqual(len(response.answers), 2)
 
+    def test_reorder_preserves_option_identity_and_existing_answers(self) -> None:
+        poll = self._poll(allow_response_update=False)
+        response = self._submit_both(poll, "person-1")
+        first_id, second_id = (option.id for option in poll.options)
+        original_answers = [dict(answer) for answer in response.answers]
+        provider = SqlPollSchedulingProvider()
+
+        reordered = provider.reorder_options(
+            self.session,
+            tenant_id="tenant-1",
+            poll_id=poll.id,
+            command=PollOptionOrderCommand(option_ids=(second_id, first_id)),
+        )
+
+        self.assertEqual(
+            [(option.id, option.position) for option in reordered.options],
+            [(second_id, 0), (first_id, 1)],
+        )
+        self.assertEqual(response.answers, original_answers)
+        self.assertIsNone(response.deleted_at)
+
+        replayed = provider.reorder_options(
+            self.session,
+            tenant_id="tenant-1",
+            poll_id=poll.id,
+            command=PollOptionOrderCommand(option_ids=(second_id, first_id)),
+        )
+        self.assertEqual(replayed.options, reordered.options)
+        self.assertEqual(response.answers, original_answers)
+
+    def test_reorder_rejects_partial_or_duplicate_active_option_order(self) -> None:
+        poll = self._poll()
+        first_id, second_id = (option.id for option in poll.options)
+        provider = SqlPollSchedulingProvider()
+
+        with self.assertRaisesRegex(PollCapabilityError, "every active option"):
+            provider.reorder_options(
+                self.session,
+                tenant_id="tenant-1",
+                poll_id=poll.id,
+                command=PollOptionOrderCommand(option_ids=(first_id,)),
+            )
+        with self.assertRaisesRegex(PollCapabilityError, "duplicate"):
+            provider.reorder_options(
+                self.session,
+                tenant_id="tenant-1",
+                poll_id=poll.id,
+                command=PollOptionOrderCommand(option_ids=(first_id, first_id)),
+            )
+
+        self.assertEqual(
+            [(option.id, option.position) for option in poll.options],
+            [(first_id, 0), (second_id, 1)],
+        )
+
 
 if __name__ == "__main__":
     unittest.main()