"""calc.py 的测试 —— dim4 fixture（禁止被测模型修改本文件）。"""

from __future__ import annotations

import unittest

from calc import add, average, clamp, div


class TestAdd(unittest.TestCase):
    def test_basic(self):
        self.assertEqual(add(1, 2), 3)

    def test_float(self):
        self.assertAlmostEqual(add(0.1, 0.2), 0.3, places=6)


class TestDiv(unittest.TestCase):
    def test_basic(self):
        self.assertEqual(div(6, 3), 2)

    def test_zero_raises_value_error(self):
        with self.assertRaises(ValueError):
            div(1, 0)


class TestAverage(unittest.TestCase):
    def test_basic(self):
        self.assertEqual(average([1, 2, 3]), 2.0)

    def test_empty_returns_zero(self):
        self.assertEqual(average([]), 0.0)


class TestClamp(unittest.TestCase):
    def test_inside(self):
        self.assertEqual(clamp(5, 0, 10), 5)

    def test_below(self):
        self.assertEqual(clamp(-3, 0, 10), 0)

    def test_above(self):
        self.assertEqual(clamp(99, 0, 10), 10)


if __name__ == "__main__":
    unittest.main()