fix: atomically apply reconciliation leases

tests/test_state.py

@@ -205,6 +205,39 @@ class ClientStoreTests(unittest.TestCase):
             self.assertEqual(row["last_event_sequence"], 0)
             self.assertEqual(row["state"], "JOB_STATE_QUEUED")
 
+    def test_reconciliation_acknowledgement_and_state_are_atomic(self):
+        with tempfile.TemporaryDirectory() as directory:
+            store = ClientStore(Path(directory) / "state.db")
+            store.initialize()
+            store.accept_command(
+                "stale", '{"executeStep":{"jobId":"job-1"}}',
+                '{"status":"COMMAND_ACK_STATUS_ACCEPTED"}',
+            )
+            accepted = store.accept_reconcile_command(
+                "reconcile-1", '{"reconcileJob":{"authoritativeJob":{}}}',
+                '{"status":"COMMAND_ACK_STATUS_ACCEPTED"}',
+                job_id="job-1", definition_json='{"jobId":"job-1"}',
+                state="JOB_STATE_QUEUED", revision=0,
+                last_event_sequence=0, committed=False,
+                superseded_command_ids=["stale"],
+            )
+            self.assertFalse(accepted.duplicate)
+            self.assertEqual(accepted.state, "accepted")
+            self.assertTrue(store.is_command_active("reconcile-1"))
+            self.assertFalse(store.is_command_active("stale"))
+            self.assertEqual(
+                store.job_snapshot_rows(["job-1"])[0]["last_event_sequence"], 0
+            )
+            duplicate = store.accept_reconcile_command(
+                "reconcile-1", '{"reconcileJob":{"authoritativeJob":{}}}',
+                '{"status":"COMMAND_ACK_STATUS_ACCEPTED"}',
+                job_id="job-1", definition_json='{"jobId":"job-1"}',
+                state="JOB_STATE_QUEUED", revision=0,
+                last_event_sequence=0, committed=False,
+                superseded_command_ids=["stale"],
+            )
+            self.assertTrue(duplicate.duplicate)
+
 
 if __name__ == "__main__":
     unittest.main()