Files
set50-system/backend/tests/test_portfolio_ledger.py

177 lines
7.5 KiB
Python

"""Tests for the portfolio accounting ledger (Task 3)."""
from __future__ import annotations
import unittest
from app.backtest_events import DIVIDEND_PAYMENT_LAG_DAYS
from app.portfolio_ledger import (
FEE_RATE,
LOT_SIZE,
PortfolioLedger,
PortfolioLedgerError,
)
SHARES = LOT_SIZE # 100
class BuySellTest(unittest.TestCase):
def test_buy_100_lots_and_average_cost(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
pos = ledger.position("A")
assert pos is not None
self.assertEqual(pos.qty, SHARES)
self.assertEqual(pos.average_cost, 100.0)
# fee 0.3% of 100*100=10,000 -> 30
expected_cost = 10_000 * FEE_RATE
self.assertAlmostEqual(ledger.state.fees, expected_cost)
self.assertAlmostEqual(
ledger.state.cash, 1_000_000 - 10_000 - expected_cost, places=2
)
def test_average_cost_after_second_buy_at_higher_price(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
ledger.buy("A", SHARES, 200.0, date="2026-02-05", signal_date="2026-02-01")
pos = ledger.position("A")
assert pos is not None
self.assertEqual(pos.qty, 2 * SHARES)
# avg = (100*100 + 200*100) / 200 = 150
self.assertAlmostEqual(pos.average_cost, 150.0, places=2)
def test_realized_pnl_uses_average_cost(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
# sell at 110 -> avg cost 100; gross realized = 11000 - 10000 = 1000
trade = ledger.sell("A", SHARES, 110.0, date="2026-03-05", signal_date="2026-03-01")
self.assertAlmostEqual(trade.realized_pnl, 1_000.0, places=2)
self.assertAlmostEqual(ledger.state.realized_pnl, 1_000.0, places=2)
# sell fee = 0.3% * 11000 = 33 tracked separately
self.assertAlmostEqual(trade.fees, 33.0, places=2)
# full exit drops the position
self.assertIsNone(ledger.position("A"))
def test_buy_requires_lot_multiple(self):
ledger = PortfolioLedger(1_000_000)
with self.assertRaises(PortfolioLedgerError):
ledger.buy("A", 50, 100.0, date="2026-01-05", signal_date="2026-01-01")
def test_buy_requires_enough_cash(self):
ledger = PortfolioLedger(10_000)
# 100 shares * 500 = 50,000 + fee > 10,000
with self.assertRaises(PortfolioLedgerError):
ledger.buy("A", SHARES, 500.0, date="2026-01-05", signal_date="2026-01-01")
def test_sell_more_than_held_rejected(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
with self.assertRaises(PortfolioLedgerError):
ledger.sell("A", 2 * SHARES, 100.0, date="2026-03-05", signal_date="2026-03-01")
class DividendTest(unittest.TestCase):
def test_entitlement_uses_shares_held_before_ex_date(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", 2 * SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
ledger.record_dividend_entitlement("A", "2026-03-10", 1.5)
self.assertEqual(len(ledger.state.receivables), 1)
r = ledger.state.receivables[0]
self.assertEqual(r.qty_entitled, 2 * SHARES)
self.assertAlmostEqual(r.amount, 2 * SHARES * 1.5, places=2)
# payment = ex_date + 30 calendar days
self.assertEqual(r.assumed_payment_date, "2026-04-09")
self.assertEqual(r.timing_method, "ex_date_plus_30d")
# NOT yet cash
self.assertAlmostEqual(ledger.state.dividend_cash_received, 0.0)
def test_no_entitlement_when_no_shares_held(self):
ledger = PortfolioLedger(1_000_000)
ledger.record_dividend_entitlement("A", "2026-03-10", 1.5)
self.assertEqual(len(ledger.state.receivables), 0)
def test_payment_credits_cash_at_ex_date_plus_30(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", 2 * SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
ledger.record_dividend_entitlement("A", "2026-03-10", 1.5)
cash_before = ledger.state.cash
# before payment date -> no credit
ledger.pay_due_dividends("2026-04-08")
self.assertAlmostEqual(ledger.state.cash, cash_before, places=2)
# on/after payment date -> credited
ledger.pay_due_dividends("2026-04-09")
self.assertAlmostEqual(
ledger.state.cash, cash_before + 2 * SHARES * 1.5, places=2
)
self.assertAlmostEqual(
ledger.state.dividend_cash_received, 2 * SHARES * 1.5, places=2
)
self.assertEqual(len(ledger.state.receivables), 0)
def test_receivable_is_not_spendable_before_payment(self):
ledger = PortfolioLedger(50_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
ledger.record_dividend_entitlement("A", "2026-03-10", 1.5)
# dividend receivable = 150, but cash is only 10,030-ish; can't buy 100*200
with self.assertRaises(PortfolioLedgerError):
ledger.buy("B", SHARES, 400.0, date="2026-03-15", signal_date="2026-03-10")
# after payment, cash grows and can fund the buy
ledger.pay_due_dividends("2026-04-09")
ledger.buy("B", SHARES, 10.0, date="2026-04-10", signal_date="2026-04-09")
self.assertEqual(ledger.qty("B"), SHARES)
class ReconcileTest(unittest.TestCase):
def test_equity_matches_market_value_plus_cash(self):
ledger = PortfolioLedger(1_000_000)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
prices = {"A": 110.0}
self.assertAlmostEqual(
ledger.equity(prices),
ledger.state.cash + 100 * 110.0,
places=2,
)
def test_reconciled_balanced_with_sell(self):
ledger = PortfolioLedger(100_000)
ledger.buy("A", SHARES, 50.0, date="2026-01-05", signal_date="2026-01-01")
ledger.sell("A", SHARES, 60.0, date="2026-02-05", signal_date="2026-02-01")
prices = {}
r = ledger.reconcile(prices)
self.assertTrue(r["balanced"])
# notional return equals realized pnl - fees
self.assertAlmostEqual(
r["notional_return"], r["realized_trading_pnl"] - r["transaction_costs"],
places=1,
)
def test_reconciled_balanced_with_holding_and_dividend(self):
ledger = PortfolioLedger(100_000)
ledger.buy("A", SHARES, 50.0, date="2026-01-05", signal_date="2026-01-01")
ledger.record_dividend_entitlement("A", "2026-03-10", 1.0)
ledger.pay_due_dividends("2026-04-09")
prices = {"A": 55.0}
r = ledger.reconcile(prices)
self.assertTrue(r["balanced"])
# equity = cash(+div) + 100*55
expected_equity = ledger.state.cash + 100 * 55.0
self.assertAlmostEqual(r["equity"], expected_equity, places=2)
class FeeConfigTest(unittest.TestCase):
def test_custom_fee_rate(self):
ledger = PortfolioLedger(1_000_000, fee_rate=0.0)
ledger.buy("A", SHARES, 100.0, date="2026-01-05", signal_date="2026-01-01")
self.assertEqual(ledger.state.fees, 0.0)
def test_invalid_fee_rate_rejected(self):
with self.assertRaises(PortfolioLedgerError):
PortfolioLedger(1000, fee_rate=1.0)
with self.assertRaises(PortfolioLedgerError):
PortfolioLedger(1000, fee_rate=-0.1)
if __name__ == "__main__":
unittest.main()