Quality assurance metric imperial converter tests

Hi I am busy completing the quality assurance certification and I am busy with the metric imperial converter and I keep failing the default of 1 if no number is given and the return a string test. I have no idea why these are failing because I have confirmed that both are working. Any assitance with these to tests will be highly appreciated thank you.

here is my project link: https://replit.com/@daniel-deru/boilerplate-project-metricimpconverter