Complete training workflow and acceptance hardening

backend/tests/test_backup_scheduler.py

@@ -1,4 +1,5 @@
 from datetime import datetime, timedelta, timezone
+from types import SimpleNamespace
 
 from scripts import backup_loop
 
@@ -18,3 +19,42 @@ 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
+
+
+def test_scheduler_waits_only_remainder_after_slow_backup(monkeypatch):
+    settings = SimpleNamespace(
+        backup_interval_seconds=86_400,
+        backup_retry_seconds=300,
+        backup_keep=14,
+    )
+    copies = []
+    waits = []
+
+    def listing():
+        return copies
+
+    def create():
+        # Model pg_dump taking 20 minutes before finishing the scheduler cycle.
+        copies.append({
+            "name": "recent.sql",
+            "at": datetime.now(timezone.utc) - timedelta(minutes=20),
+        })
+        return {"name": "recent.sql", "size_bytes": 123}
+
+    def sleep(seconds):
+        waits.append(seconds)
+        raise RuntimeError("stop after observing next scheduled wait")
+
+    monkeypatch.setattr(backup_loop, "get_settings", lambda: settings)
+    monkeypatch.setattr(backup_loop, "listing", listing)
+    monkeypatch.setattr(backup_loop, "create", create)
+    monkeypatch.setattr(backup_loop, "prune", lambda keep: 0)
+    monkeypatch.setattr(backup_loop.time, "sleep", sleep)
+
+    try:
+        backup_loop.run_forever()
+    except RuntimeError as exc:
+        assert str(exc) == "stop after observing next scheduled wait"
+
+    assert len(waits) == 1
+    assert 85_190 <= waits[0] <= 85_200