Revert "Delete solutions/tests/test_largest_number.py"

This reverts commit 138c90a.

solutions/tests/test_largest_number.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Unit tests for the largest_number function.
+
+Test categories:
+Standard cases: Typical lists with positive, negative, and mixed integers.
+Edge cases: Empty lists, lists with a single element, lists with duplicate values.
+Defensive tests: Non-list inputs (e.g., integers, strings), lists with non-integer elements,
+assertions for invalid inputs.
+
+Created on 2025-01-11
+Author: Azza
+"""
+
+import unittest
+
+from ..largest_number import largest_number
+
+
+class TestLargestNumber(unittest.TestCase):
+    """Unit tests for the largest_number function."""
+
+    def test_standard_list(self):
+        """It should return 9 for [0, 1, 9, 2, 6, 4]."""
+        self.assertEqual(largest_number([0, 1, 9, 2, 6, 4]), 9)
+
+    def test_single_element(self):
+        """It should return 12 for [12]."""
+        self.assertEqual(largest_number([12]), 12)
+
+    def test_mixed_positive_and_negative(self):
+        """It should return 8 for [8, -1, -8, 5]."""
+        self.assertEqual(largest_number([8, -1, -8, 5]), 8)
+
+    def test_all_negative_numbers(self):
+        """It should return -1 for [-9, -1, -6, -5]."""
+        self.assertEqual(largest_number([-9, -1, -6, -5]), -1)
+
+    def test_all_zeros(self):
+        """It should return 0 for [0, 0]."""
+        self.assertEqual(largest_number([0, 0]), 0)
+
+    def test_large_numbers(self):
+        """It should return 4294967296 for [2**32, 2**16, 2**8, 1]."""
+        self.assertEqual(largest_number([2**32, 2**16, 2**8, 1]), 2**32)
+
+    def test_empty_list(self):
+        """It should raise ValueError for an empty list."""
+        with self.assertRaises(ValueError):
+            largest_number([])
+
+    def test_non_list_input(self):
+        """It should raise TypeError for non-list input, e.g., 42."""
+        with self.assertRaises(TypeError):
+            largest_number(42)
+
+    def test_list_with_non_integer(self):
+        """It should raise TypeError for a list with non-integer elements."""
+        with self.assertRaises(TypeError):
+            largest_number(["-5", 5, "0"])
+
+
+if __name__ == "__main__":
+    unittest.main()