feat(sp41): claim-id dedup at SFTP pre-flight (30-day window, configurable)

backend/tests/test_submission_dedup.py

@@ -0,0 +1,38 @@
+"""Claim-id dedup at the SFTP pre-flight stage."""
+from datetime import datetime
+from cyclone.store.submission_dedup import (
+    DuplicateClaimError,
+    record_submission,
+    check_duplicate,
+    DEFAULT_WINDOW_DAYS,
+)
+
+
+def test_check_duplicate_returns_none_for_first_submission(tmp_path):
+    db = tmp_path / "test.db"
+    assert check_duplicate("ORIG-001", db_url=f"sqlite:///{db}") is None
+
+
+def test_check_duplicate_raises_within_window(tmp_path):
+    db = tmp_path / "test.db"
+    record_submission("ORIG-002", submitted_at=datetime(2026, 6, 1), db_url=f"sqlite:///{db}")
+    try:
+        check_duplicate("ORIG-002", db_url=f"sqlite:///{db}",
+                       now=datetime(2026, 6, 15))
+    except DuplicateClaimError as e:
+        assert e.claim_id == "ORIG-002"
+        assert e.original_submission_at == datetime(2026, 6, 1)
+    else:
+        raise AssertionError("expected DuplicateClaimError")
+
+
+def test_check_duplicate_passes_after_window(tmp_path):
+    db = tmp_path / "test.db"
+    record_submission("ORIG-003", submitted_at=datetime(2026, 1, 1), db_url=f"sqlite:///{db}")
+    # 100 days later — past the 30-day default window
+    assert check_duplicate("ORIG-003", db_url=f"sqlite:///{db}",
+                          now=datetime(2026, 4, 11)) is None
+
+
+def test_default_window_is_30_days():
+    assert DEFAULT_WINDOW_DAYS == 30