请将以下导入语句中的模块名替换为实际代码所在模块
例如：from my_module import calculate_order_total
from decimal import Decimal
import pytest
from target_module import calculate_order_total # 修改为你的模块名
def test_typical_order_percent_discount_with_cap_and_tax_returns_decimal_and_correct_total():
items = [
{'price': '30', 'qty': 2}, # subtotal = 60
]
discount = {'type': 'percent', 'value': '0.10', 'cap': Decimal('5')} # 10% capped at 5 -> discount = 5
tax_rate = Decimal('0.07') # 7%
total = calculate_order_total(items, discount=discount, tax_rate=tax_rate)
# taxed_base = 60 - 5 = 55; tax = 55 * 0.07 = 3.85; total = 58.85 -> Decimal rounded to 2 places
assert isinstance(total, Decimal)
assert total == Decimal('58.85')
def test_empty_cart_returns_zero_decimal_two_places():
total = calculate_order_total([], discount=None, tax_rate=Decimal('0'))
assert isinstance(total, Decimal)
assert total == Decimal('0.00')
def test_tax_rate_boundary_zero_no_tax():
items = [{'price': '10', 'qty': 2}] # subtotal = 20
total = calculate_order_total(items, tax_rate=Decimal('0'))
assert total == Decimal('20.00')
def test_tax_rate_boundary_one_full_tax_on_discounted_base():
items = [{'price': 10, 'qty': 1}] # subtotal = 10
discount = {'type': 'fixed', 'value': 2} # taxed_base = 8
total = calculate_order_total(items, discount=discount, tax_rate=Decimal('1.0')) # total = 8 + 8 = 16
assert total == Decimal('16.00')
def test_fixed_discount_exceeds_subtotal_caps_to_zero_total_even_with_tax():
items = [{'price': '12', 'qty': 1}] # subtotal = 12
discount = {'type': 'fixed', 'value': '100'} # discount capped to subtotal -> taxed_base = 0
total = calculate_order_total(items, discount=discount, tax_rate=Decimal('0.07'))
assert total == Decimal('0.00')
def test_negative_price_raises_value_error():
items = [{'price': -1, 'qty': 1}]
with pytest.raises(ValueError, match='价格与数量需非负'):
calculate_order_total(items)
def test_negative_quantity_raises_value_error():
items = [{'price': '1.00', 'qty': -2}]
with pytest.raises(ValueError, match='价格与数量需非负'):
calculate_order_total(items)
def test_tax_rate_below_zero_raises_value_error():
items = [{'price': '1', 'qty': 1}]
with pytest.raises(ValueError, match='税率需在0到1之间'):
calculate_order_total(items, tax_rate=Decimal('-0.01'))
def test_tax_rate_above_one_raises_value_error():
items = [{'price': '1', 'qty': 1}]
with pytest.raises(ValueError, match='税率需在0到1之间'):
calculate_order_total(items, tax_rate=Decimal('1.0001'))
def test_unknown_discount_type_raises_value_error():
items = [{'price': '10', 'qty': 1}]
discount = {'type': 'bogus', 'value': '0.1'}
with pytest.raises(ValueError, match='未知折扣类型'):
calculate_order_total(items, discount=discount)
def test_prices_and_discount_accept_float_and_string_safely_converted_to_decimal():
items = [
{'price': 19.9, 'qty': 1}, # float price
{'price': '10.10', 'qty': 2}, # string price
]
discount = {'type': 'percent', 'value': '0.1'} # string percent
tax_rate = 0.075 # float tax rate
total = calculate_order_total(items, discount=discount, tax_rate=tax_rate)
# subtotal = 19.9 + 20.2 = 40.1
# discount = 40.1 * 0.1 = 4.01
# taxed_base = 36.09
# tax = 36.09 * 0.075 = 2.70675
# total = 38.79675 -> ROUND_HALF_UP to 38.80
assert total == Decimal('38.80')
def test_discount_cap_negative_raises_value_error():
items = [{'price': '10', 'qty': 1}]
discount = {'type': 'percent', 'value': '0.1', 'cap': '-1'}
with pytest.raises(ValueError, match='折扣封顶需非负'):
calculate_order_total(items, discount=discount)
def test_rounding_half_up_to_two_decimal_places():
items = [{'price': '0.01', 'qty': 1}] # subtotal = 0.01
# tax = 0.01 * 0.5 = 0.005; total = 0.015 -> ROUND_HALF_UP -> 0.02
total = calculate_order_total(items, tax_rate=Decimal('0.5'))
assert total == Decimal('0.02')
@pytest.mark.parametrize("bad_item", [
{'qty': 1}, # missing price
{'price': '1.00'}, # missing qty
])
def test_item_missing_price_or_qty_raises_value_error(bad_item):
with pytest.raises(ValueError, match='item缺少price或qty'):
calculate_order_total([bad_item])
@pytest.mark.parametrize("bad_percent", ['-0.1', Decimal('1.1')])
def test_percent_discount_out_of_range_raises_value_error(bad_percent):
items = [{'price': '10', 'qty': 1}]
discount = {'type': 'percent', 'value': bad_percent}
with pytest.raises(ValueError, match='百分比折扣需在0到1之间'):
calculate_order_total(items, discount=discount)
def test_fixed_discount_negative_raises_value_error():
items = [{'price': '10', 'qty': 1}]
discount = {'type': 'fixed', 'value': '-5'}
with pytest.raises(ValueError, match='固定折扣需非负'):
calculate_order_total(items, discount=discount)
