Merge pull request #3260 from dd2480-spring-2025-group-1/kim/test-cases-for-bot-utils-helpers

fix: `has_lines` returns empty str instead of bool

Author: ChrisLovering

bot/utils/helpers.py

@@ -25,7 +25,7 @@ def has_lines(string: str, count: int) -> bool:
     split = string.split("\n", count - 1)
 
     # Make sure the last part isn't empty, which would happen if there was a final newline.
-    return split[-1] and len(split) == count
+    return split[-1] != "" and len(split) == count
 
 
 def pad_base64(data: str) -> str:

tests/bot/utils/test_helpers.py

@@ -0,0 +1,113 @@
+import unittest
+
+from bot.utils import helpers
+
+
+class TestHelpers(unittest.TestCase):
+    """Tests for the helper functions in the `bot.utils.helpers` module."""
+
+    def test_find_nth_occurrence_returns_index(self):
+        """Test if `find_nth_occurrence` returns the index correctly when substring is found."""
+        test_values = (
+            ("hello", "l", 1, 2),
+            ("hello", "l", 2, 3),
+            ("hello world", "world", 1, 6),
+            ("hello world", " ", 1, 5),
+            ("hello world", "o w", 1, 4)
+        )
+
+        for string, substring, n, expected_index in test_values:
+            with self.subTest(string=string, substring=substring, n=n):
+                index = helpers.find_nth_occurrence(string, substring, n)
+                self.assertEqual(index, expected_index)
+
+    def test_find_nth_occurrence_returns_none(self):
+        """Test if `find_nth_occurrence` returns None when substring is not found."""
+        test_values = (
+            ("hello", "w", 1, None),
+            ("hello", "w", 2, None),
+            ("hello world", "world", 2, None),
+            ("hello world", " ", 2, None),
+            ("hello world", "o w", 2, None)
+        )
+
+        for string, substring, n, expected_index in test_values:
+            with self.subTest(string=string, substring=substring, n=n):
+                index = helpers.find_nth_occurrence(string, substring, n)
+                self.assertEqual(index, expected_index)
+
+    def test_has_lines_handles_normal_cases(self):
+        """Test if `has_lines` returns True for strings with at least `count` lines."""
+        test_values = (
+            ("hello\nworld", 1, True),
+            ("hello\nworld", 2, True),
+            ("hello\nworld", 3, False),
+        )
+
+        for string, count, expected in test_values:
+            with self.subTest(string=string, count=count):
+                result = helpers.has_lines(string, count)
+                self.assertEqual(result, expected)
+
+    def test_has_lines_handles_empty_string(self):
+        """Test if `has_lines` returns False for empty strings."""
+        test_values = (
+            ("", 0, False),
+            ("", 1, False),
+        )
+
+        for string, count, expected in test_values:
+            with self.subTest(string=string, count=count):
+                result = helpers.has_lines(string, count)
+                self.assertEqual(result, expected)
+
+    def test_has_lines_handles_newline_at_end(self):
+        """Test if `has_lines` ignores one newline at the end."""
+        test_values = (
+            ("hello\nworld\n", 2, True),
+            ("hello\nworld\n", 3, False),
+            ("hello\nworld\n\n", 3, True),
+        )
+
+        for string, count, expected in test_values:
+            with self.subTest(string=string, count=count):
+                result = helpers.has_lines(string, count)
+                self.assertEqual(result, expected)
+
+    def test_pad_base64_correctly(self):
+        """Test if `pad_base64` correctly pads a base64 string."""
+        test_values = (
+            ("", ""),
+            ("a", "a==="),
+            ("aa", "aa=="),
+            ("aaa", "aaa="),
+            ("aaaa", "aaaa"),
+            ("aaaaa", "aaaaa==="),
+            ("aaaaaa", "aaaaaa=="),
+            ("aaaaaaa", "aaaaaaa=")
+        )
+
+        for data, expected in test_values:
+            with self.subTest(data=data):
+                result = helpers.pad_base64(data)
+                self.assertEqual(result, expected)
+
+    def test_remove_subdomain_from_url_correctly(self):
+        """Test if `remove_subdomain_from_url` correctly removes subdomains from URLs."""
+        test_values = (
+            ("https://example.com", "https://example.com"),
+            ("https://www.example.com", "https://example.com"),
+            ("https://sub.example.com", "https://example.com"),
+            ("https://sub.sub.example.com", "https://example.com"),
+            ("https://sub.example.co.uk", "https://example.co.uk"),
+            ("https://sub.sub.example.co.uk", "https://example.co.uk"),
+            ("https://sub.example.co.uk/path", "https://example.co.uk/path"),
+            ("https://sub.sub.example.co.uk/path", "https://example.co.uk/path"),
+            ("https://sub.example.co.uk/path?query", "https://example.co.uk/path?query"),
+            ("https://sub.sub.example.co.uk/path?query", "https://example.co.uk/path?query"),
+        )
+
+        for url, expected in test_values:
+            with self.subTest(url=url):
+                result = helpers.remove_subdomain_from_url(url)
+                self.assertEqual(result, expected)