1import unittest
 2from unittest.mock import patch, mock_open
 3from bangaranga import does_the_banga_rang, TheBangaDoesNotRangError
 4
 5class TestDoesBangaRanga(unittest.TestCase):
 6
 7    @patch("builtins.open", mock_open(read_data="banga the ranga"))
 8    def test_two_words(self):
 9        result = does_the_banga_rang("тук_няма_значение_какво_е.txt")
10        self.assertEqual(result, 2)
11
12    @patch("builtins.open", mock_open(read_data="bang a small ranga"))
13    def test_three_words(self):
14        result = does_the_banga_rang("ама_наистина_няма_знaчение.txt")
15        self.assertEqual(result, 3)
16
17    @patch("builtins.open", mock_open(read_data="chunga-changa bangaranga"))
18    def test_single_word_bangaranga(self):
19        result = does_the_banga_rang("ще_си_пуша_когато_на_мен_ми_се_пуши.txt")
20        self.assertEqual(result, 1)
21
22    @patch("builtins.open", mock_open(read_data="ranga banga"))
23    def test_wrong_order_returns_zero(self):
24        result = does_the_banga_rang("не_си_познал.txt")
25        self.assertEqual(result, 0)
26
27    @patch("builtins.open", mock_open(read_data="BANGARANGA"))
28    def test_case_insensitive(self):
29        result = does_the_banga_rang("пуша_си_цигарата_и_не_ми_пука_че_лукът_е_лев_и_двайсет.txt")
30        self.assertEqual(result, 1)
31
32    @patch("builtins.open", mock_open(read_data="banga ranga bangaranga ban garan ga"))
33    def test_minimum_word_count(self):
34        result = does_the_banga_rang("пуша_си_цигарата_и_не_ми_пука_че_лукът_е_лев_и_двайсет.txt")
35        self.assertEqual(result, 1)
36
37    @patch("builtins.open", side_effect=OSError)
38    def test_missing_file_raises_custom_error(self, mock_file):
39        with self.assertRaises(TheBangaDoesNotRangError):
40            does_the_banga_rang("откакто_се_помъкна_с_тая.txt")
41
42    @patch("builtins.open", mock_open(read_data="banga something"))
43    def test_incomplete_bangaranga_returns_zero(self):
44        result = does_the_banga_rang("направо_ми_счерни_живота.txt")
45        self.assertEqual(result, 0)
46
47    @patch("builtins.open", mock_open(read_data="xbangaranga"))
48    def test_word_boundary(self):
49        result = does_the_banga_rang("само_ме_ядосва.txt")
50        self.assertEqual(result, 0)
51
52    @patch("builtins.open", mock_open(read_data=""))
53    def test_empty_file_returns_zero(self):
54        result = does_the_banga_rang("вече_нямам_нещо_готино_да_кажа.txt")
55        self.assertEqual(result, 0)
56
57    @patch("builtins.open", side_effect=IOError)
58    def test_io_error_raises_custom_error(self, mock_file):
59        with self.assertRaises(TheBangaDoesNotRangError):
60            does_the_banga_rang("адиос_мучачос_компанйерос_бай_бай_чао_по_дяволитее.txt")