Why are the nushell completions not part of the completions crate?

[Kissaki]

Completions offers multiple shells, but Nushell is split off into a separate crate.

Combining them to offer both sets of completions requires some boilerplate, including replicating/duplicating the choice enum with Nushell added.

The readmes of neither project have information regarding this.

starship/starship#6366

[epage]

We used to have another shell like this which was removed.

We have not defined our policy for when a shell gets promoted to be in the default set. For nushell, the extra burden to test and the tracking of breaking changes does not help.

[epage]

There are actually two distinctions for us to make:

• integrated into clap_complete
• enabled by default

Thinking more on this, there are multiple considerations

• The expected longevity / popularity of the shell
• Our ability to maintain support for the shell (e.g. problems like clap_complete::env::Elvish generates code deprecated in 0.18, removed in 0.21 #5729)
• Whether we should automatically add to the compatibility surface of callers

For that last one, if we add new shells to Shell, existing applications will get it for free by upgrading, whether they want it or not. I wonder if we should extend Shell in breaking releases and we should likely shrink it from where it is currently at to be very conservative.

[FrancescElies]

I see your point, what should happen to make you reconsider making it part of main completions crate?
E.g. Elvish is pre-1.0 software like nushell but seems to have a place in the main crate. I guess the high development pace of nushell might be the main reason.

If this merge would happen nushell users would get completions almost for free for projects using the main crate once they update.

Lately I have been experiencing less and less breaking changes that affected nushell code I have written.

NOTE: I am not affiliated to the nushell project but I use it as my daily driver

[alerque]

It might be tine to reconsider this. I'm a packager for Arch Linux and regularly run into complains when Nushell doesn't get any love with completions for projects we package. Looking at Arch usage stats, 4.5× more people have Nushell installed that Elvish (which somehow made the default cut). That is installations and doesn't say anything about what people are actually using, but it is a decent relative metric. I don't use it personally, but by all reports Nushell getting pretty stable.

[Kissaki]

I was surprised to see dotnet 10, with the introduction of shell completion generating subcommand, supports Nushell as well.
I don't know what led to their choices of shells, though.
Still, it surprised me to see it in such a mainstream and enterprise tool.

https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-10/sdk#native-shell-tab-completion-scripts

[epage]

Related: #5329