🧪 [testing improvement description] Add test suite for python fibonacci function

.gitignore

@@ -52,3 +52,4 @@ c/.idea/c.iml
 /dataSources/
 /dataSources.local.xml
 /httpRequests/
+__pycache__/

python/test_recursion.py

@@ -0,0 +1,50 @@
+"""
+Tests for the recursive algorithms in python/recursion.py.
+"""
+
+import unittest
+from unittest.mock import patch
+import io
+import sys
+import os
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+from recursion import factorial, fib, addup
+
+class TestRecursion(unittest.TestCase):
+    """
+    Test suite for the recursive functions in recursion.py.
+    """
+
+    def test_fib_negative(self):
+        """
+        Test that fib handles negative inputs by printing 'Incorrect input' and returning None.
+        """
+        with patch('sys.stdout', new_callable=io.StringIO) as mock_stdout:
+            result = fib(-1)
+            self.assertIsNone(result)
+            self.assertEqual(mock_stdout.getvalue().strip(), "Incorrect input")
+
+    def test_fib_base_cases(self):
+        """
+        Test the base cases for the fibonacci sequence.
+        """
+        self.assertEqual(fib(1), 0)
+        self.assertEqual(fib(2), 1)
+
+    def test_fib_positive(self):
+        """
+        Test the recursive case for a known positive index.
+        """
+        self.assertEqual(fib(8), 13)
+
+    def test_fib_zero_raises_typeerror(self):
+        """
+        Test that fib(0) raises a TypeError due to None + None.
+        """
+        with patch('sys.stdout', new_callable=io.StringIO):
+            with self.assertRaises(TypeError):
+                fib(0)
+
+if __name__ == '__main__':
+    unittest.main()