fixed assertions to fetch Exceptions and assert message

tests/test_solution.py

@@ -1,4 +1,5 @@
 import sys
+import pytest
 from io import StringIO
 from nordhealth_test.solution import print_pairs_with_same_sum
 
@@ -43,13 +44,15 @@ def test_no_valid_pairs():
 # Test case: Array with exactly one element
 def test_single_element():
     arr = [10]
-    expected_output = "No pairs can be formed from the input file.\n"
-    result = capture_output(print_pairs_with_same_sum, arr)
-    assert result == expected_output
+    expected_output = "No pairs can be formed from the input file."
+    with pytest.raises(ValueError) as val_error:
+        capture_output(print_pairs_with_same_sum, arr)
+    assert str(val_error.value) == expected_output
 
 # Test case: Empty array
 def test_empty_array():
     arr = []
-    expected_output = "No pairs can be formed from the input file.\n"
-    result = capture_output(print_pairs_with_same_sum, arr)
-    assert result == expected_output
+    expected_output = "No pairs can be formed from the input file."
+    with pytest.raises(ValueError) as val_error:
+        capture_output(print_pairs_with_same_sum, arr)
+    assert str(val_error.value) == expected_output