cli: extend flags completion

[ccoVeille]

Welcome

• Yes, I've searched similar issues on GitHub and didn't find any.
• I agree to follow this project's Code of Conduct

Your feature request related to a problem? Please describe

I would like to be able to complete the flag values such as --out-format=git<TAB> or --enable-only=use<TAB>

Right now, only the flags are completed, not their values

Describe the solution you'd like

The tool uses cobra, we could use

https://pkg.go.dev/github.com/spf13/cobra#Command.RegisterFlagCompletionFunc

Describe alternatives you've considered

Define my own completions locally 😅

Additional context

I took a look at the code, most flag will be "easy"

Some might require a small refactoring because of the helpers defined in the code

Supporter

• I am a sponsor through GitHub or OpenCollective

[ccoVeille]

I prepared this integration by improving the documentation of an existing method

https://pkg.go.dev/github.com/spf13/cobra@master#FixedCompletions

• feat: add CompletionFunc type to help with completions spf13/cobra#2220

There is no need for latest cobra code to be tagged and used. I only worked on the documentation, that was a bit unclear

[ldez]

For the v2, I will change the linters management and the configuration, so unless you are not changing any existing code, I would prefer to not implement this for now.

[ccoVeille]

OK. Thanks for the feedback.

I could open PRs for adding completion to flags where it's about adding a few lines of code per command.

And the ones that might require a refactoring could be left aside.

I think this small changes could bring a nice feature.

EDIT: I put my suggestion on hold now, I've seen the v2 refactoring suggested here

• 🌟 Let's talk about output formats options #5364