fix: enforce snapshot-consistent precision checks for manual ledger

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

tests/test_bat025_portfolio_ledger_manual_metadata_migration.py

@@ -9,7 +9,7 @@ or production application database.
 from __future__ import annotations
 
 import os
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from decimal import Decimal
 from urllib.parse import unquote, urlparse
 from uuid import uuid4
@@ -106,10 +106,9 @@ def _current_revision(settings: Settings) -> str:
         user=settings.active_db_user,
         password=settings.active_db_password,
         sslmode=settings.active_db_sslmode,
-    ) as conn:
-        with conn.cursor() as cur:
-            cur.execute("SELECT version_num FROM alembic_version")
-            return str(cur.fetchone()[0])
+    ) as conn, conn.cursor() as cur:
+        cur.execute("SELECT version_num FROM alembic_version")
+        return str(cur.fetchone()[0])
 
 
 def _metadata_columns(settings: Settings) -> dict[str, tuple[str, str, str | None]]:
@@ -120,18 +119,17 @@ def _metadata_columns(settings: Settings) -> dict[str, tuple[str, str, str | Non
         user=settings.active_db_user,
         password=settings.active_db_password,
         sslmode=settings.active_db_sslmode,
-    ) as conn:
-        with conn.cursor() as cur:
-            cur.execute(
-                """
+    ) as conn, conn.cursor() as cur:
+        cur.execute(
+            """
                 SELECT column_name, data_type, is_nullable, column_default
                 FROM information_schema.columns
                 WHERE table_schema = 'public' AND table_name = 'portfolio_ledger'
                   AND column_name IN ('source', 'target_ledger_entry_id',
                                       'confirmation_evidence', 'actor_user_id')
                 """
-            )
-            return {row[0]: (row[1], row[2], row[3]) for row in cur.fetchall()}
+        )
+        return {row[0]: (row[1], row[2], row[3]) for row in cur.fetchall()}
 
 
 def _seed_portfolio(repo: PostgresPortfolioRepository, suffix: str) -> str:
@@ -169,7 +167,7 @@ def test_upgrade_from_pre_0028_preserves_business_data_and_backfills_source(
     command.upgrade(get_alembic_config(isolated_settings), _PRE_BAT025)
     repo = _repo(isolated_settings)
     portfolio_id = _seed_portfolio(repo, "preserve")
-    recorded_at = datetime(2026, 7, 15, tzinfo=timezone.utc)
+    recorded_at = datetime(2026, 7, 15, tzinfo=UTC)
     with repo._connect().cursor() as cur:
         cur.execute(
             """
@@ -249,7 +247,7 @@ def test_broker_and_manual_ledger_writes_regress_after_real_upgrade(
         side="buy",
         quantity=2,
         price=100,
-        executed_at=datetime.now(timezone.utc),
+        executed_at=datetime.now(UTC),
     )
     manual = repo.record_manual_ledger(
         portfolio_id,
@@ -287,7 +285,7 @@ def test_dividend_precision_and_reversal_round_trip_on_real_postgres(
         action="DIVIDEND",
         amount=Decimal("0.00000001"),
         tax=Decimal("0.00000001"),
-        executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=timezone.utc),
+        executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=UTC),
         note="precision-test",
     )
 
@@ -352,7 +350,60 @@ def test_dividend_large_integer_with_8dp_is_rejected_to_protect_double_snapshot(
             action="DIVIDEND",
             amount=Decimal("1000000000.00000001"),
             tax=Decimal("0.00000001"),
-            executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=timezone.utc),
+            executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=UTC),
             note="too-large-for-double",
         )
     repo.close()
+
+
+def test_large_existing_buffer_plus_min_dividend_is_rejected_before_snapshot_divergence(
+    isolated_settings: Settings,
+) -> None:
+    """Reject writes that would diverge between NUMERIC ledger and DOUBLE snapshot."""
+    upgrade_to_head(isolated_settings)
+    repo = _repo(isolated_settings)
+    portfolio_id = _seed_portfolio(repo, "large-buffer-min-dividend")
+    with repo._connect().cursor() as cur:
+        cur.execute("UPDATE portfolios SET profit_buffer = %s WHERE portfolio_id = %s", (1_000_000_000.0, portfolio_id))
+
+    with pytest.raises(ValueError, match="DOUBLE PRECISION snapshot"):
+        repo.record_manual_ledger(
+            portfolio_id,
+            action="DIVIDEND",
+            amount=Decimal("0.00000001"),
+            executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=UTC),
+            note="should-reject",
+        )
+
+    with repo._connect().cursor() as cur:
+        cur.execute("SELECT COUNT(*) FROM portfolio_ledger WHERE portfolio_id = %s AND side = 'dividend'", (portfolio_id,))
+        assert cur.fetchone()[0] == 0
+    repo.close()
+
+
+def test_large_invest_and_large_dividend_tax_metadata_are_accepted_when_snapshot_is_safe(
+    isolated_settings: Settings,
+) -> None:
+    """No hidden per-field cap for values that do not cause snapshot divergence."""
+    upgrade_to_head(isolated_settings)
+    repo = _repo(isolated_settings)
+    portfolio_id = _seed_portfolio(repo, "large-invest-large-tax")
+
+    invest = repo.record_manual_ledger(
+        portfolio_id,
+        action="INVEST",
+        amount=Decimal("50000000.00000000"),
+        note="large-invest",
+    )
+    assert invest.price == 50000000.0
+
+    dividend = repo.record_manual_ledger(
+        portfolio_id,
+        action="DIVIDEND",
+        amount=Decimal("1.00000000"),
+        tax=Decimal("50000000.00000000"),
+        executed_at=datetime(2026, 9, 1, 0, 0, 0, tzinfo=UTC),
+        note="large-tax-metadata",
+    )
+    assert dividend.tax_amount == 50000000.0
+    repo.close()

tests/test_v1_portfolios_manual_ledger.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from contextlib import ExitStack
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from typing import Any
 from unittest.mock import patch
 
@@ -195,7 +195,7 @@ class _FakeRepo:
             fee_amount=fee,
             tax_amount=tax,
             executed_at=executed_at,
-            recorded_at=datetime.now(timezone.utc),
+            recorded_at=datetime.now(UTC),
             cash_balance_after=self.portfolio.cash_balance,
             asset_quantity_after=self.portfolio.asset_quantity,
             profit_buffer_after=self.portfolio.profit_buffer,
@@ -674,7 +674,7 @@ def test_unified_ledger_paginates_mixed_sources_and_hides_side() -> None:
     repo.entries.append(
         LedgerEntry(
             ledger_entry_id=99, portfolio_id=_PORTFOLIO_ID, side="buy", quantity=2, price=10, source="broker",
-            recorded_at=datetime.now(timezone.utc), cash_balance_after=900, asset_quantity_after=12,
+            recorded_at=datetime.now(UTC), cash_balance_after=900, asset_quantity_after=12,
         )
     )
     first = client.get(f"/v1/portfolios/{_PORTFOLIO_ID}/ledger?limit=1", headers=_auth())