test_calculator.py

import unittest
from calculator import Calculator

class TestCalculator(unittest.TestCase):
    def setUp(self):
        self.calc = Calculator()
    
    def test_add(self):
        self.assertEqual(self.calc.add(1, 2), 3)
        self.assertEqual(self.calc.add(-1, 1), 0)
        self.assertEqual(self.calc.add(0, 0), 0)
    
    def test_subtract(self):
        self.assertEqual(self.calc.subtract(10, 5), 5)
        self.assertEqual(self.calc.subtract(2, 3), -1)
        self.assertEqual(self.calc.subtract(0, 0), 0)
    
    def test_multiply(self):
        self.assertEqual(self.calc.multiply(3, 4), 12)
        self.assertEqual(self.calc.multiply(-1, 5), -5)
        self.assertEqual(self.calc.multiply(0, 100), 0)
    
    def test_divide(self):
        self.assertEqual(self.calc.divide(10, 2), 5)
        self.assertEqual(self.calc.divide(-10, 2), -5)
        with self.assertRaises(ValueError):
            self.calc.divide(10, 0)
        with self.assertRaises(ValueError):
            self.calc.divide(0, 0)

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