Complete DDS training workflow and delivery package

backend/tests/test_backup_scheduler.py

@@ -0,0 +1,20 @@
+from datetime import datetime, timedelta, timezone
+
+from scripts import backup_loop
+
+
+def test_no_backup_is_due_immediately(monkeypatch):
+    monkeypatch.setattr(backup_loop, "listing", lambda: [])
+    assert backup_loop.seconds_until_due(datetime.now(timezone.utc), 86_400) == 0
+
+
+def test_fresh_backup_waits_only_for_remaining_interval(monkeypatch):
+    now = datetime.now(timezone.utc)
+    monkeypatch.setattr(backup_loop, "listing", lambda: [{"at": now - timedelta(hours=6)}])
+    assert backup_loop.seconds_until_due(now, 86_400) == 18 * 3600
+
+
+def test_overdue_backup_is_due_immediately(monkeypatch):
+    now = datetime.now(timezone.utc)
+    monkeypatch.setattr(backup_loop, "listing", lambda: [{"at": now - timedelta(days=2)}])
+    assert backup_loop.seconds_until_due(now, 86_400) == 0