Refactor file structure, update imports, and add new tests

.vscode/settings.json

@@ -119,8 +119,8 @@
     "editor.defaultFormatter": "charliermarsh.ruff",
     "editor.formatOnSave": true,
     "editor.codeActionsOnSave": {
-      "source.fixAll.ruff": true,
-      "source.organizeImports.ruff": true
+      "source.fixAll.ruff": "explicit",
+      "source.organizeImports.ruff": "explicit"
     }
   }
 }

solutions/__init__.py

@@ -1 +0,0 @@
-

solutions/is_palindrome.py

@@ -32,6 +32,7 @@ def is_palindrome(text: str) -> bool:
         >>> is_palindrome("A man a plan a canal Panama")
         True
     """
+    # Ensure the input is of type string to avoid unexpected errors.
     assert isinstance(text, str), "Input must be a string"
 
     # Normalize the text: remove spaces and convert to lowercase

solutions/tests/test_is_palindrome.py

@@ -0,0 +1,58 @@
+import unittest
+from solutions.is_palindrome import is_palindrome
+
+
+class TestIsPalindrome(unittest.TestCase):
+    """Test the is_palindrome function."""
+
+    def test_empty_string(self):
+        """It should return True for an empty string."""
+        self.assertTrue(is_palindrome(""))
+
+    def test_single_character(self):
+        """It should return True for single character strings."""
+        self.assertTrue(is_palindrome("a"))
+
+    def test_level_palindrome(self):
+        """It should return True for the palindrome 'level'."""
+        self.assertTrue(is_palindrome("level"))
+
+    def test_radar_palindrome(self):
+        """It should return True for the palindrome 'radar'."""
+        self.assertTrue(is_palindrome("radar"))
+
+    def test_hello_is_not_palindrome(self):
+        """It should return False for the non-palindrome 'hello'."""
+        self.assertFalse(is_palindrome("hello"))
+
+    def test_world_is_not_palindrome(self):
+        """It should return False for the non-palindrome 'world'."""
+        self.assertFalse(is_palindrome("world"))
+
+    def test_mixed_case_palindromes_return_true(self):
+        """It should return True for palindromes with mixed lower-case and upper-case characters."""
+        self.assertTrue(is_palindrome("RaceCar"))
+
+    def test_palindromes_with_spaces_return_true(self):
+        """It should return True for palindromes with spaces and mixed cases."""
+        self.assertTrue(is_palindrome("A man a plan a canal Panama"))
+
+    def test_palindrome_with_numbers_returns_true(self):
+        """It should return True for palindromes containing numbers."""
+        self.assertTrue(is_palindrome("12321"))
+
+    def test_non_palindrome_numbers_return_false(self):
+        """It should return False for non-palindrome numbers."""
+        self.assertFalse(is_palindrome("12345"))
+
+    def test_palindrome_with_special_characters_returns_true(self):
+        """It should return True for palindromes with special characters."""
+        self.assertTrue(is_palindrome("!@#$%^&*()_+_)(*&^%$#@!"))
+
+    def test_non_palindrome_with_special_characters_returns_false(self):
+        """It should return False for non-palindromes with special characters."""
+        self.assertFalse(is_palindrome("hello!"))
+
+
+if __name__ == "__main__":
+    unittest.main()