Probly doesn't have built-in test assertion functionality yet, but since it runs Python (via Pyodide) directly in the browser, you can write test functions with assertions in your Python code. The execute_python_code tool in our system can run any valid Python code, including test functions.
This is something we're considering for future development, so this is a great shout!
This is something we're considering for future development, so this is a great shout!