Unit Testing with unittest

import unittest

# Code to test
def add(a, b):
    return a + b

def divide(a, b):
    if b == 0:
        raise ValueError("Cannot divide by zero")
    return a / b

def is_palindrome(text):
    clean = text.lower().replace(" ", "")
    return clean == clean[::-1]

# Test class
class TestMathFunctions(unittest.TestCase):
    
    def setUp(self):
        """Runs before each test."""
        self.data = [1, 2, 3, 4, 5]
    
    def test_add_positive(self):
        self.assertEqual(add(2, 3), 5)
    
    def test_add_negative(self):
        self.assertEqual(add(-1, -1), -2)
    
    def test_add_zero(self):
        self.assertEqual(add(0, 0), 0)
    
    def test_divide(self):
        self.assertAlmostEqual(divide(10, 3), 3.333, places=2)
    
    def test_divide_by_zero(self):
        with self.assertRaises(ValueError):
            divide(10, 0)
    
    def test_palindrome(self):
        self.assertTrue(is_palindrome("racecar"))
        self.assertTrue(is_palindrome("A man a plan a canal Panama"))
        self.assertFalse(is_palindrome("hello"))

# Run tests
print("=== Running Tests ===")
suite = unittest.TestLoader().loadTestsFromTestCase(TestMathFunctions)
runner = unittest.TextTestRunner(verbosity=2)
runner.run(suite)

# Key assertions:
# assertEqual(a, b)     — a == b
# assertNotEqual(a, b)  — a != b
# assertTrue(x)         — bool(x) is True
# assertFalse(x)        — bool(x) is False
# assertRaises(Error)   — exception raised
# assertIn(a, b)        — a in b
# assertIsNone(x)       — x is None
# assertAlmostEqual(a, b) — a ≈ b