#!/usr/bin/env python3
from unittest import TestCase, main

from mathematik import fak

class FacultyTester(TestCase):
    def test_basic(self):
        self.assertEqual(fak(0), 1)
        self.assertEqual(fak(1), 1)

    def test_basic2(self):
        self.assertTrue(fak(0) == 1)
        self.assertTrue(fak(1) == 1)

    def test_basic3(self):
        self.assertFalse(fak(0) == 0)
    
    def test_greater(self):
        for n in range(2,10):
            self.assertGreater(fak(n), fak(n-1))
    def test_invalid(self):
        with self.assertRaises(Exception):
            fak(-1)
        with self.assertRaises(ValueError):
            fak(-1)

if __name__ == '__main__':
    main()