How to add version option to a custom group

[deepu9]

Thanks to all the developers for bringing click python package to everyone. It's an amazing package and makes building command line tools a breeze. I've been using click for quite sometime and always recommend others too.

Recently I stumbled up on a task, which is to add --version option for package(main) and sub packages. This is my first time working on custom groups. We've created a custom group class and added list_commands() and get_command() methods to get sub packages commands.

click - v7.x
python - v3.9

Following is what we've used for reference
https://click.palletsprojects.com/en/7.x/commands/#custom-multi-commands

I did look into version_option decorator, but I don't think I can add a decorator to the custom group class. So, I've added the --version option in the custom group class __init__() method:

class TestGroup(click.Group):
    def __init__(*args, **kwargs):
        kwargs["params"].append(
            click.Option(...)
        )

and add invoke() method to the TestGroup class, which gets the version info from version_option decorator, but it throws error saying this command doesn't have a name attribute.

I understand I'm doing it wrong, but not sure how to proceed it. Can you guide me. Thanks