# retoor <retoor@molodetz.nl>

import unittest

from src.calculator import add, subtract, multiply, divide


class TestCalculator(unittest.TestCase):

    def test_add(self) -> None:
        self.assertEqual(add(2, 3), 5)

    def test_subtract(self) -> None:
        self.assertEqual(subtract(5, 3), 2)

    def test_multiply_positive(self) -> None:
        self.assertEqual(multiply(2, 3), 6)

    def test_multiply_negative_left(self) -> None:
        self.assertEqual(multiply(-2, 3), -6)

    def test_multiply_negative_right(self) -> None:
        self.assertEqual(multiply(2, -3), -6)

    def test_multiply_both_negative(self) -> None:
        self.assertEqual(multiply(-2, -3), 6)

    def test_multiply_zero_left(self) -> None:
        self.assertEqual(multiply(0, 5), 0)

    def test_multiply_zero_right(self) -> None:
        self.assertEqual(multiply(5, 0), 0)

    def test_multiply_both_zero(self) -> None:
        self.assertEqual(multiply(0, 0), 0)

    def test_divide_positive(self) -> None:
        self.assertEqual(divide(6, 3), 2)

    def test_divide_negative_left(self) -> None:
        self.assertEqual(divide(-6, 3), -2)

    def test_divide_negative_right(self) -> None:
        self.assertEqual(divide(6, -3), -2)

    def test_divide_both_negative(self) -> None:
        self.assertEqual(divide(-6, -3), 2)

    def test_divide_floor(self) -> None:
        self.assertEqual(divide(7, 3), 2)

    def test_divide_zero_numerator(self) -> None:
        self.assertEqual(divide(0, 5), 0)

    def test_divide_by_zero(self) -> None:
        with self.assertRaises(ValueError) as cm:
            divide(5, 0)
        self.assertEqual(str(cm.exception), 'division by zero')