fix(portfolios): replay corporate-action cost basis (#38)

tests/test_issue34_regressions.py

@@ -2,6 +2,8 @@ from datetime import UTC, date, datetime
 from decimal import Decimal
 from pathlib import Path
 
+import pytest
+
 from app.domain.corporate_actions import canonical_payload_hash
 from app.domain.pnl import calculate_current_wac, calculate_realized_pnl
 from app.schemas.corporate_actions import CorporateActionRequest
@@ -10,7 +12,7 @@ from app.schemas.corporate_actions import CorporateActionRequest
 def test_buy_consolidation_sell_replays_wac_and_realized_pnl():
     rows = [
         {"side": "buy", "quantity": 10, "price": 100, "fee_amount": 0, "tax_amount": 0, "executed_at": datetime(2026, 1, 1, tzinfo=UTC)},
-        {"side": "stock_consolidation", "quantity": 0, "price": 0, "quantity_before": 10, "quantity_after": 5, "average_price_after": 200, "executed_at": datetime(2026, 1, 2, tzinfo=UTC)},
+        {"side": "stock_consolidation", "quantity": 0, "price": 0, "quantity_before": 10, "quantity_after": 5, "average_price_after": 200, "total_cost_basis": 1000, "executed_at": datetime(2026, 1, 2, tzinfo=UTC)},
         {"side": "sell", "quantity": 2, "price": 250, "fee_amount": 0, "tax_amount": 0, "executed_at": datetime(2026, 1, 3, tzinfo=UTC)},
     ]
     assert calculate_current_wac(rows).current_wac == 200
@@ -35,6 +37,59 @@ def test_consolidation_replay_uses_preserved_total_cost_basis():
     result = calculate_current_wac(rows)
     assert result.current_quantity == 726
     assert result.current_wac == float(Decimal("1577211.97990000") / Decimal(726))
+    assert result.total_cost_basis == float(Decimal("1577211.97990000"))
+    assert result.data_completeness_warning is None
+
+
+def test_consolidation_replay_ignores_rounded_average_price_after():
+    rows = [
+        {"side": "buy", "quantity": 1452, "price": 1086.2341459366393},
+        {
+            "side": "stock_consolidation",
+            "quantity_after": 726,
+            "average_price_after": Decimal("1.00"),
+            "total_cost_basis": Decimal("1577211.97990000"),
+        },
+    ]
+
+    result = calculate_current_wac(rows)
+    assert result.current_wac == float(Decimal("1577211.97990000") / Decimal(726))
+    assert result.total_cost_basis == float(Decimal("1577211.97990000"))
+
+
+@pytest.mark.parametrize(
+    "metadata",
+    [
+        {"total_cost_basis": Decimal(1000)},
+        {"quantity_after": 0, "total_cost_basis": Decimal(1000)},
+        {"quantity_after": 5},
+    ],
+)
+def test_consolidation_replay_fails_closed_when_required_metadata_is_missing(metadata):
+    rows = [
+        {"side": "buy", "quantity": 10, "price": 100},
+        {"side": "stock_consolidation", **metadata},
+    ]
+
+    result = calculate_current_wac(rows)
+    assert result.current_wac is None
+    assert result.total_cost_basis is None
+    assert result.data_completeness_warning is not None
+    assert "기업행동 metadata" in result.data_completeness_warning
+
+
+def test_consolidation_authoritative_total_continues_through_later_trades():
+    rows = [
+        {"side": "buy", "quantity": 10, "price": 100},
+        {"side": "stock_consolidation", "quantity_after": 5, "total_cost_basis": Decimal(1000)},
+        {"side": "buy", "quantity": 1, "price": 300, "fee_amount": 2},
+        {"side": "sell", "quantity": 2, "price": 400},
+    ]
+
+    result = calculate_current_wac(rows)
+    assert result.current_quantity == 4
+    assert result.current_wac == pytest.approx(1302 / 6)
+    assert result.total_cost_basis == pytest.approx((1302 / 6) * 4)
 
 
 def test_canonical_hash_same_payload_and_changed_payload_differ():