Fix debug code challenge (#4632)

tests/challenges/debug_code/data/test.py

@@ -0,0 +1,31 @@
+# mypy: ignore-errors
+from code import two_sum
+from typing import List
+
+
+def test_two_sum(nums: List, target: int, expected_result: List[int]) -> None:
+    result = two_sum(nums, target)
+    print(result)
+    assert (
+        result == expected_result
+    ), f"AssertionError: Expected the output to be {expected_result}"
+
+
+if __name__ == "__main__":
+    # test the trivial case with the first two numbers
+    nums = [2, 7, 11, 15]
+    target = 9
+    expected_result = [0, 1]
+    test_two_sum(nums, target, expected_result)
+
+    # test for ability to use zero and the same number twice
+    nums = [2, 7, 0, 15, 12, 0]
+    target = 0
+    expected_result = [2, 5]
+    test_two_sum(nums, target, expected_result)
+
+    # test for first and last index usage and negative numbers
+    nums = [-6, 7, 11, 4]
+    target = -2
+    expected_result = [0, 3]
+    test_two_sum(nums, target, expected_result)