import unittest


def is_prime(n):
    """Checks if a number is prime."""
    if n <= 1:
        return False
    for i in range(2, int(n**0.5) + 1):
        if n % i == 0:
            return False
    return True


def sum_of_first_n_primes(n):
    """Calculates the sum of the first n prime numbers."""
    count = 0
    num = 2
    prime_sum = 0
    while count < n:
        if is_prime(num):
            prime_sum += num
            count += 1
        num += 1
    return prime_sum


class TestPrimes(unittest.TestCase):

    def test_is_prime_non_positive(self):
        test_name = "test_is_prime_non_positive"
        try:
            self.assertFalse(is_prime(0))
            self.assertFalse(is_prime(-1))
            self.assertFalse(is_prime(-2))
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_is_prime_non_integer(self):
        test_name = "test_is_prime_non_integer"
        try:
            self.assertFalse(is_prime("a"))
            self.assertFalse(is_prime(1.5))
            self.assertFalse(is_prime([1, 2, 3]))
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_is_prime_true(self):
        test_name = "test_is_prime_true"
        try:
            self.assertTrue(is_prime(2))
            self.assertTrue(is_prime(3))
            self.assertTrue(is_prime(5))
            self.assertTrue(is_prime(7))
            self.assertTrue(is_prime(11))
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_is_prime_false(self):
        test_name = "test_is_prime_false"
        try:
            self.assertFalse(is_prime(4))
            self.assertFalse(is_prime(6))
            self.assertFalse(is_prime(8))
            self.assertFalse(is_prime(9))
            self.assertFalse(is_prime(10))
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_sum_of_first_n_primes_invalid_input(self):
        test_name = "test_sum_of_first_n_primes_invalid_input"
        try:
            self.assertEqual(sum_of_first_n_primes(0), 0)
            self.assertEqual(sum_of_first_n_primes(-1), 0)
            self.assertEqual(sum_of_first_n_primes("abc"), 0)
            self.assertEqual(sum_of_first_n_primes(3.14), 0)
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_sum_of_first_n_primes_small_n(self):
        test_name = "test_sum_of_first_n_primes_small_n"
        try:
            self.assertEqual(sum_of_first_n_primes(1), 2)
            self.assertEqual(sum_of_first_n_primes(2), 5)
            self.assertEqual(sum_of_first_n_primes(3), 10)
            self.assertEqual(sum_of_first_n_primes(4), 17)
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")

    def test_sum_of_first_n_primes_larger_n(self):
        test_name = "test_sum_of_first_n_primes_larger_n"
        try:
            self.assertEqual(sum_of_first_n_primes(5), 28)
            print(f"{test_name}: *** test_passed ***")
        except AssertionError:
            print(f"{test_name}: *** assertion_failed ***")
        except Exception as e:
            print(f"{test_name}: *** exception_raised ***, error message: {e}")


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