from src.tutorial.testing.shop.pricing import discount_price
import pytest


def test_discount_price_reduces_price():
    result = discount_price(100.0, 20.0)
    assert result == 80

    assert discount_price(100.0, 50.0) == 50
    assert discount_price(100.0, 0) == 100
    assert discount_price(100.0, 100) == 0


def test_negative_orice_raises_value_error() -> None:
    with pytest.raises(ValueError):
        discount_price(-100.0, 50.0) is ValueError


def test_percent_above_hundered_message() -> None:
    with pytest.raises(ValueError, match="between 0 and 100"):
        discount_price(100.0, 150.0)