Hello,
I tried to add a test but I have trouble making the test suite work locally. Not sure if I miss some dependencies.

To test the CLI entrypoints, you would need to use typer.testing.CliRunner.

There are some examples in Pyodide repository, which might be helpful to you. If you find it difficult to write tests, let us know. I think we can merge this PR and add some tests later.

I gave it a try: https://github.com/pyodide/pyodide-lock/actions/runs/9431128434/job/26020165688?pr=29

But it is not clear to me why the test fails at this point. If you have any input would be grateful, otherwise I try to have a look in the following days.

But it is not clear to me why the test fails at this point.

It's becuase that function has a decorator @main.command(), and typer converts the function internally to make it work as a CLI entrypoint. Calling the typer-decorated function directly will not work as expected. Could you take a look at the link that I provided?