fix(portfolio): tolerate consolidation WAC residue

2026-09-13 18:36:00 +09:00
parent 4520fbbfbd
commit 2b470c735f
14 changed files with 146 additions and 34 deletions
@@ -16,3 +16,16 @@ def test_stock_consolidation_rejects_fractional_result():
    with pytest.raises(CorporateActionError) as exc:
        calculate_stock_consolidation(Decimal(3), Decimal("1.5"), Decimal(10))
    assert exc.value.code == "FRACTIONAL_RESULT_UNSUPPORTED"
+
+
+def test_stock_consolidation_allows_stored_wac_rounding_residue():
+    result = calculate_stock_consolidation(
+        Decimal(1452),
+        Decimal(726),
+        Decimal("1086.234145936639256198347107438016528926"),
+    )
+
+    assert result.average_price_before == Decimal("1086.23414594")
+    assert result.average_price_after == Decimal("2172.46829187")
+    assert result.total_cost_basis == Decimal("1577211.97990000")
+    assert result.total_cost_basis - result.average_price_after * result.quantity_after == Decimal("0.00000238")