zwitschi
795a9f99f4
- Updated form template to prefill currency input with default value and added help text for clarity. - Modified integration tests to assert more descriptive error messages for invalid currency codes. - Introduced new tests for currency normalization and validation in various scenarios, including imports and exports. - Added comprehensive tests for pricing calculations, ensuring defaults are respected and overrides function correctly. - Implemented unit tests for pricing settings repository, ensuring CRUD operations and default settings are handled properly. - Enhanced scenario pricing evaluation tests to validate currency handling and metadata defaults. - Added simulation tests to ensure Monte Carlo runs are accurate and handle various distribution scenarios.
163 lines
4.5 KiB
Python
163 lines
4.5 KiB
Python
from __future__ import annotations
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from datetime import date
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import pytest
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from services.financial import (
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CashFlow,
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PaybackNotReachedError,
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internal_rate_of_return,
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net_present_value,
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normalize_cash_flows,
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payback_period,
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)
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def test_normalize_cash_flows_with_dates() -> None:
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base = date(2025, 1, 1)
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period_length = 365.0 / 4
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flows = [
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CashFlow(amount=-1_000_000, date=base),
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CashFlow(amount=350_000, date=date(2025, 4, 1)),
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CashFlow(amount=420_000, date=date(2025, 7, 1)),
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]
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normalised = normalize_cash_flows(flows, compounds_per_year=4)
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assert normalised[0] == (-1_000_000.0, 0.0)
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expected_second = (date(2025, 4, 1) - base).days / period_length
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expected_third = (date(2025, 7, 1) - base).days / period_length
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assert normalised[1][1] == pytest.approx(expected_second, rel=1e-6)
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assert normalised[2][1] == pytest.approx(expected_third, rel=1e-6)
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def test_net_present_value_with_period_indices() -> None:
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rate = 0.10
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flows = [
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CashFlow(amount=-1_000, period_index=0),
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CashFlow(amount=500, period_index=1),
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CashFlow(amount=500, period_index=2),
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CashFlow(amount=500, period_index=3),
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]
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expected = -1_000 + sum(500 / (1 + rate) **
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period for period in range(1, 4))
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result = net_present_value(rate, flows)
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assert result == pytest.approx(expected, rel=1e-9)
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def test_net_present_value_with_residual_value() -> None:
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rate = 0.08
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flows = [
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CashFlow(amount=-100_000, period_index=0),
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CashFlow(amount=30_000, period_index=1),
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CashFlow(amount=35_000, period_index=2),
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]
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expected = (
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-100_000
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+ 30_000 / (1 + rate)
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+ 35_000 / (1 + rate) ** 2
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+ 25_000 / (1 + rate) ** 3
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)
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result = net_present_value(rate, flows, residual_value=25_000)
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assert result == pytest.approx(expected, rel=1e-9)
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def test_internal_rate_of_return_simple_case() -> None:
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flows = [
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CashFlow(amount=-1_000, period_index=0),
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CashFlow(amount=1_210, period_index=1),
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]
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irr = internal_rate_of_return(flows, guess=0.05)
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assert irr == pytest.approx(0.21, rel=1e-9)
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def test_internal_rate_of_return_multiple_sign_changes() -> None:
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flows = [
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CashFlow(amount=-500_000, period_index=0),
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CashFlow(amount=250_000, period_index=1),
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CashFlow(amount=-100_000, period_index=2),
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CashFlow(amount=425_000, period_index=3),
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]
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irr = internal_rate_of_return(flows, guess=0.2)
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npv = net_present_value(irr, flows)
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assert npv == pytest.approx(0.0, abs=1e-6)
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def test_internal_rate_of_return_requires_mixed_signs() -> None:
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flows = [
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CashFlow(amount=100_000, period_index=0),
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CashFlow(amount=150_000, period_index=1),
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]
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with pytest.raises(ValueError):
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internal_rate_of_return(flows)
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def test_payback_period_exact_period() -> None:
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flows = [
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CashFlow(amount=-120_000, period_index=0),
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CashFlow(amount=40_000, period_index=1),
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CashFlow(amount=40_000, period_index=2),
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CashFlow(amount=40_000, period_index=3),
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]
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period = payback_period(flows, allow_fractional=False)
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assert period == pytest.approx(3.0)
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def test_payback_period_fractional_period() -> None:
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flows = [
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CashFlow(amount=-100_000, period_index=0),
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CashFlow(amount=80_000, period_index=1),
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CashFlow(amount=30_000, period_index=2),
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]
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fractional = payback_period(flows)
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whole = payback_period(flows, allow_fractional=False)
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assert fractional == pytest.approx(1 + 20_000 / 30_000, rel=1e-9)
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assert whole == pytest.approx(2.0)
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def test_payback_period_raises_when_never_recovered() -> None:
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flows = [
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CashFlow(amount=-250_000, period_index=0),
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CashFlow(amount=50_000, period_index=1),
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CashFlow(amount=60_000, period_index=2),
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CashFlow(amount=70_000, period_index=3),
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]
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with pytest.raises(PaybackNotReachedError):
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payback_period(flows)
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def test_payback_period_with_quarterly_compounding() -> None:
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base = date(2025, 1, 1)
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flows = [
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CashFlow(amount=-120_000, date=base),
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CashFlow(amount=35_000, date=date(2025, 4, 1)),
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CashFlow(amount=35_000, date=date(2025, 7, 1)),
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CashFlow(amount=50_000, date=date(2025, 10, 1)),
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]
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period = payback_period(flows, compounds_per_year=4)
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period_length = 365.0 / 4
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expected_period = (date(2025, 10, 1) - base).days / period_length
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assert period == pytest.approx(expected_period, abs=1e-6)
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