Completions: add support for doas as for sudo

[ZerdoX-x]

Description

Fixes #2047 but for the doas command the same way as in #8094

Screenshots

Fixes this difference:

User-Facing Changes

No breaking changes. If people not using doas, no difference at all.

Tests

I have not added any tests since its using same logic as for "sudo". I guess if something would go wrong in this part, sudo tests will cover it?

Additional context

As a nushell user I could not find a way to implement custom completion for a "sudo like command". Since I can see sudo being hardcoded in sources, this is what I propose.

Also I have almost zero knowledge of rust and this is definitely not the clean way yet

[sholderbach]

Thanks for giving this a shot!
No fault for not being familiar with Rust yet. In this case your changes not yet add support for command completion after sudo/doas. In the screenshot you can see that it only suggests files (which I think it will fallback to quite liberally)

[ZerdoX-x]

@sholderbach thank you so much for review <3

Screenshots are just illustration of the problem, not it's solution :D

I've made changes according to your code advice.

[ZerdoX-x]

@sholderbach Hi :)
I've resolved merge conflict and added doas to typos false positives so CI check would not complain.
Could you please take a look?

[sholderbach]

Thanks for iterating on this!

I think we should in the future have a way to simply provide a list of commands or a signature that will take external commands and arguments in the trailing position.

But to get this resolved I am fine with landing this right now so we can unblock

[fdncred]

Darn, I forgot about gsudo, that I sometimes use on windows. Now that I think about it, maybe it also has a sudo version of the command?

[ZerdoX-x]

I think we should in the future have a way to simply provide a list of commands or a signature that will take external commands and arguments in the trailing position.

Definitely. As Darren mentioned, it may be some other commands or just any command that wraps other binaries. I could not find a way to implement custom completion with current level of interfaces and/or documentation.

Do you want me to open an issue for this?

[fdncred]

Do you want me to open an issue for this?

I think so. Thanks!

[p00f]

@ZerdoX-x before this PR, I used to do it with

let doas_completer = {|spans: list<string>|
    do $env.config.completions.external.completer ($spans | skip 1)
}

# This completer will use carapace by default
let external_completer = {|spans|
    let expanded_alias = (scope aliases | where name == $spans.0 | get -i 0.expansion)
    let spans = if $expanded_alias != null  {
        $spans | skip 1 | prepend ($expanded_alias | split words)
    } else {
        $spans
    }

    match $spans.0 {
        doas => $doas_completer
        _ => $carapace_fish_completer
    } | do $in $spans
}
$env.config = {
    completions: {
        external: {
            enable: true
            completer: $external_completer
        }
    }
}

[p00f]

note that pkexec is another sudo-like command

[ZerdoX-x]

before this PR, I used to do it with

I think anyways I'll open another issue since there are plenty of commands who accept another program as their first parameter. The most basic example here is which, which is not supported by nushell built-in completions. I am not sure this is user friendly, to make people write this in order to support which, exec and other commands :D

[p00f]

which just takes other programs, you don't have to provide completions for the other program's arguments. agree on exec