🧪 单元测试生成

输入 — 被测函数

框架:pytest

def apply_discount(price, percent):
    """按百分比打折后返回价格,保留 2 位小数。"""
    if price < 0:
        raise ValueError("price must be non-negative")
    if not 0 <= percent <= 100:
        raise ValueError("percent must be 0..100")
    return round(price * (1 - percent / 100), 2)

输出 — 生成的测试套件

import pytest
from pricing import apply_discount

def test_basic_discount():
    assert apply_discount(100.0, 20) == 80.0

def test_rounds_to_two_dp():
    assert apply_discount(9.99, 15) == 8.49

def test_zero_percent_is_unchanged():
    assert apply_discount(50.0, 0) == 50.0

def test_full_discount_is_zero():
    assert apply_discount(50.0, 100) == 0.0

def test_negative_price_raises():
    with pytest.raises(ValueError):
        apply_discount(-1.0, 10)

@pytest.mark.parametrize("p", [-5, 101])
def test_percent_out_of_range_raises(p):
    with pytest.raises(ValueError):
        apply_discount(100.0, p)