fix(worker): one-shot run exits 0 after a successful pass

tests/test_worker_oneshot_exit.py

@@ -0,0 +1,35 @@
+"""One-shot worker must exit 0 after a successful pass (#168)."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+from unittest import mock
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1] / "validator" / "src"
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+
+def test_oneshot_exits_zero_even_when_work_was_done(monkeypatch):
+    import eval_backend.worker as worker
+
+    monkeypatch.setattr(
+        worker,
+        "Settings",
+        mock.Mock(load=mock.Mock(return_value=mock.Mock(
+            ensure_dirs=mock.Mock(),
+        ))),
+    )
+    monkeypatch.setattr(worker, "build_engine", mock.Mock())
+    monkeypatch.setattr(worker, "Base", mock.Mock(metadata=mock.Mock(create_all=mock.Mock())))
+    monkeypatch.setattr(worker, "ensure_schema", mock.Mock())
+    monkeypatch.setattr(worker, "build_session_factory", mock.Mock(return_value=object()))
+    monkeypatch.setattr(worker, "process_once", mock.Mock(return_value=1))
+    monkeypatch.setattr(sys, "argv", ["worker"])
+
+    with pytest.raises(SystemExit) as ei:
+        worker.main()
+    assert ei.value.code == 0

validator/src/eval_backend/worker.py

@@ -344,7 +344,10 @@ def main() -> None:
     session_factory = build_session_factory(engine)
 
     if not args.loop:
-        raise SystemExit(process_once(session_factory, settings))
+        # process_once returns a "did work" signal (1/0), not an exit status.
+        # One-shot success must exit 0 whether or not the queue had a job (#168).
+        process_once(session_factory, settings)
+        raise SystemExit(0)
 
     while True:
         processed = process_once(session_factory, settings)