updated testcase file

tests/memory_statistics_test.py

@@ -82,6 +82,23 @@ def test_memory_statistics_retention_period(mock_db):
         )
 
 
+def test_memory_statistics_retention_period_exception(mock_db):
+    """Test setting retention period for Memory Statistics when an exception occurs."""
+    mock_db.get_table.return_value = {"memory_statistics": {}}
+    runner = CliRunner()
+    retention_period_value = 30
+
+    # Mock `mod_entry` to raise an exception.
+    mock_db.mod_entry.side_effect = Exception("Simulated retention period error")
+
+    with patch("click.echo") as mock_echo:
+        result = runner.invoke(memory_statistics_retention_period, [str(retention_period_value)])
+        assert result.exit_code == 0  # Ensure the command exits without crashing.
+
+        # Check that the error message was outputted.
+        mock_echo.assert_any_call("Error setting retention period: Simulated retention period error", err=True)
+
+
 def test_memory_statistics_sampling_interval(mock_db):
     """Test setting the sampling interval for Memory Statistics."""
     mock_db.get_table.return_value = {"memory_statistics": {}}