feat(sp39): Resubmission model + migration 0021 + idempotency tests

backend/tests/test_resubmissions_table.py

@@ -0,0 +1,92 @@
+"""SP39: Resubmission model + idempotency.
+
+Schema:
+- 7 columns: id, claim_id, batch_id, resubmitted_at, source_corrected_path,
+  interchange_control_number, group_control_number
+- Unique index on (claim_id, interchange_control_number) -> re-insert is rejected.
+"""
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+import pytest
+from sqlalchemy.exc import IntegrityError
+
+from cyclone import db as cycl_db
+from cyclone.db import Resubmission
+
+
+def test_resubmission_model_columns():
+    cols = {c.name for c in Resubmission.__table__.columns}
+    assert cols == {
+        "id", "claim_id", "batch_id", "resubmitted_at",
+        "source_corrected_path",
+        "interchange_control_number", "group_control_number",
+    }
+
+
+def test_unique_index_on_claim_id_and_icn():
+    idx_names = {i.name for i in Resubmission.__table__.indexes}
+    assert "ux_resubmissions_claim_icn" in idx_names
+    ux = next(
+        i for i in Resubmission.__table__.indexes if i.name == "ux_resubmissions_claim_icn"
+    )
+    assert ux.unique is True
+    # The unique index covers both columns.
+    cols = {c.name for c in ux.columns}
+    assert cols == {"claim_id", "interchange_control_number"}
+
+
+def test_duplicate_insert_raises_integrity_error():
+    """Idempotency contract: a second insert with the same
+    (claim_id, interchange_control_number) is rejected at the DB layer."""
+    cycl_db.init_db()
+    now = datetime.now(timezone.utc)
+    with cycl_db.SessionLocal()() as s:
+        s.add(Resubmission(
+            claim_id="claim-x", batch_id="batch-y",
+            resubmitted_at=now,
+            source_corrected_path="/path/one",
+            interchange_control_number="000000001",
+            group_control_number="1",
+        ))
+        s.commit()
+    with cycl_db.SessionLocal()() as s:
+        s.add(Resubmission(
+            claim_id="claim-x", batch_id="batch-y",
+            resubmitted_at=now,
+            source_corrected_path="/path/two",
+            interchange_control_number="000000001",  # same ICN
+            group_control_number="1",
+        ))
+        with pytest.raises(IntegrityError):
+            s.commit()
+        s.rollback()
+
+
+def test_different_icn_on_same_claim_is_allowed():
+    """Distinct ICNs (i.e. distinct pushes) are independent rows."""
+    cycl_db.init_db()
+    now = datetime.now(timezone.utc)
+    with cycl_db.SessionLocal()() as s:
+        s.add(Resubmission(
+            claim_id="claim-y", batch_id="batch-y",
+            resubmitted_at=now,
+            source_corrected_path="/path/one",
+            interchange_control_number="000000001",
+            group_control_number="1",
+        ))
+        s.add(Resubmission(
+            claim_id="claim-y", batch_id="batch-y",
+            resubmitted_at=now,
+            source_corrected_path="/path/two",
+            interchange_control_number="000000002",  # different ICN
+            group_control_number="2",
+        ))
+        s.commit()
+    with cycl_db.SessionLocal()() as s:
+        from sqlalchemy import select
+        rows = s.execute(select(Resubmission).where(
+            Resubmission.claim_id == "claim-y"
+        )).scalars().all()
+        assert len(rows) == 2