def test_quantize():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
result = price_range.quantize()
assert str(result.start.amount) == "10.00"
assert str(result.stop.amount) == "30.00"
def test_construction():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
assert price_range.start == price1
assert price_range.stop == price2
with pytest.raises(ValueError):
CurrencyRange(price1, Currency(20, "PLN"))
with pytest.raises(ValueError):
CurrencyRange(price2, price1)
def test_replace():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price3 = Currency(20, "EUR")
price_range = CurrencyRange(price1, price2)
result = price_range.replace(stop=price3)
assert result.start == price1
assert result.stop == price3
result = price_range.replace(start=price3)
assert result.start == price3
assert result.stop == price2
def test_addition_with_money_range():
price1 = CurrencyWithTax(Currency(10, "EUR"), Currency(15, "EUR"))
price2 = CurrencyWithTax(Currency(30, "EUR"), Currency(45, "EUR"))
price_range1 = CurrencyRangeTax(price1, price2)
price3 = Currency(40, "EUR")
price4 = Currency(80, "EUR")
price_range2 = CurrencyRange(price3, price4)
result = price_range1 + price_range2
assert result.start == price1 + price3
assert result.stop == price2 + price4
with pytest.raises(ValueError):
price_range1 + CurrencyRange(Currency(1, "BTC"), Currency(2, "BTC"))
def test_subtraction_with_money_range():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range1 = CurrencyRange(price1, price2)
price3 = CurrencyWithTax(Currency(40, "EUR"), Currency(60, "EUR"))
price4 = CurrencyWithTax(Currency(80, "EUR"), Currency(120, "EUR"))
price_range2 = CurrencyRangeTax(price3, price4)
result = price_range2 - price_range1
assert result.start == price3 - price1
assert result.stop == price4 - price2
with pytest.raises(ValueError):
price_range2 - CurrencyRange(Currency(1, "BTC"), Currency(2, "BTC"))
def test_comparison():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range1 = CurrencyRange(price1, price2)
price3 = Currency(40, "EUR")
price4 = Currency(80, "EUR")
price_range2 = CurrencyRange(price3, price4)
assert price_range1 == CurrencyRange(price1, price2)
assert price_range1 != price_range2
assert price_range1 != CurrencyRange(price1, price1)
assert price_range1 != CurrencyRange(Currency(10, "USD"),
Currency(30, "USD"))
assert price_range1 != price1
def test_addition_with_money():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
price3 = Currency(40, "EUR")
result = price_range + price3
assert result.start == price1 + price3
assert result.stop == price2 + price3
with pytest.raises(ValueError):
price_range + Currency(1, "BTC")
def test_membership():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
assert price1 in price_range
assert price2 in price_range
assert (price1 + price2) / 2 in price_range
assert price1 + price2 not in price_range
with pytest.raises(TypeError):
15 in price_range
def test_subtraction_with_money():
price1 = Currency(40, "EUR")
price2 = Currency(80, "EUR")
price_range = CurrencyRange(price1, price2)
price3 = Currency(10, "EUR")
result = price_range - price3
assert result.start == price1 - price3
assert result.stop == price2 - price3
with pytest.raises(ValueError):
price_range - Currency(1, "BTC")
def test_range():
price_range = CurrencyRange(Currency(10, "BTC"), Currency(20, "BTC"))
result = flat_tax(price_range, 1)
assert result.start == CurrencyWithTax(Currency(10, "BTC"), Currency(20, "BTC"))
assert result.stop == CurrencyWithTax(Currency(20, "BTC"), Currency(40, "BTC"))
price_range = CurrencyRangeTax(
CurrencyWithTax(Currency(10, "BTC"), Currency(10, "BTC")),
CurrencyWithTax(Currency(20, "BTC"), Currency(20, "BTC")),
)
result = flat_tax(price_range, 1)
assert result.start == CurrencyWithTax(Currency(10, "BTC"), Currency(20, "BTC"))
assert result.stop == CurrencyWithTax(Currency(20, "BTC"), Currency(40, "BTC"))
def test_application():
price = CurrencyWithTax(Currency(30, "BTC"), Currency(30, "BTC"))
discount = partial(fixed_discount, discount=Currency(10, "BTC"))
result = discount(price)
assert result.net == Currency(20, "BTC")
assert result.gross == Currency(20, "BTC")
price_range = CurrencyRange(price.net, price.net)
result = discount(price_range)
assert result.start == Currency(20, "BTC")
assert result.stop == Currency(20, "BTC")
price_range = CurrencyRangeTax(price, price)
result = discount(price_range)
assert result.start == CurrencyWithTax(Currency(20, "BTC"),
Currency(20, "BTC"))
assert result.stop == CurrencyWithTax(Currency(20, "BTC"),
Currency(20, "BTC"))
with pytest.raises(TypeError):
discount(1)
def fixed_discount(base: T, discount: Currency) -> T:
"""Apply a fixed discount to any currency type."""
if isinstance(base, CurrencyRange):
return CurrencyRange(
fixed_discount(base.start, discount), fixed_discount(base.stop, discount)
)
if isinstance(base, CurrencyRangeTax):
return CurrencyRangeTax(
fixed_discount(base.start, discount), fixed_discount(base.stop, discount)
)
if isinstance(base, CurrencyWithTax):
return CurrencyWithTax(
net=fixed_discount(base.net, discount),
gross=fixed_discount(base.gross, discount),
)
if isinstance(base, Currency):
return max(base - discount, Currency(0, base.currency))
raise TypeError("Unknown base for fixed_discount: %r" % (base,))
def fractional_discount(base: T, fraction: Decimal, *, from_gross=True) -> T:
"""Apply a fractional discount based on either gross or net amount."""
if isinstance(base, CurrencyRange):
return CurrencyRange(
fractional_discount(base.start, fraction, from_gross=from_gross),
fractional_discount(base.stop, fraction, from_gross=from_gross),
)
if isinstance(base, CurrencyRangeTax):
return CurrencyRangeTax(
fractional_discount(base.start, fraction, from_gross=from_gross),
fractional_discount(base.stop, fraction, from_gross=from_gross),
)
if isinstance(base, CurrencyWithTax):
if from_gross:
discount = (base.gross * fraction).quantize(rounding=ROUND_DOWN)
else:
discount = (base.net * fraction).quantize(rounding=ROUND_DOWN)
return fixed_discount(base, discount)
if isinstance(base, Currency):
discount = (base * fraction).quantize(rounding=ROUND_DOWN)
return fixed_discount(base, discount)
raise TypeError("Unknown base for fractional_discount: %r" % (base,))
def test_currency():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
assert price_range.currency == "EUR"
def test_str():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
assert str(price_range) == ("CurrencyRange(10 EUR 30 EUR)")
def test_subtraction_with_other_types():
price1 = Currency(40, "EUR")
price2 = Currency(80, "EUR")
price_range = CurrencyRange(price1, price2)
with pytest.raises(TypeError):
price_range - 1
def test_addition_with_other_types():
price1 = Currency(10, "EUR")
price2 = Currency(30, "EUR")
price_range = CurrencyRange(price1, price2)
with pytest.raises(TypeError):
price_range + 1