autocompletions

[cgsdev0]

if you assign this to me ill do it

[amonks]

@cgsdev0 assigned 💞

[amonks]

@cgsdev0 How does shipping shell completions work?

Is it like a man page where you have to put a file in some os-dependent place on disk?

(I'm really asking: how does this ticket impact our install process? would we need to integrate with package managers?)

[cgsdev0]

i don't really know tbh

we can try to find some prior art

[amonks]

got curious, did some digging.

shells expect to find a "completion file", which is a shell script that invokes that shell's "complete" builtin a lot of times, in a particular os-specific shell-specific folder.

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one prior art

the cobra library (very fancy go framework for cli tools) adds a command to your CLI which prints a completion file for a given shell:

$tool completion --shell {bash|fish|zsh|powershell}

A user can then run something like this to install the completion:

$tool completion --shell fish > "(pkg-config --variable completionsdir fish)/$tool.fish"

Their pacakge-manager configurations work the same way, eg Macports

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another prior art is https://github.com/posener/complete/tree/master, which seems a teensy bit ramshackle (the api is poorly considered, it installs completions to the wrong place, the installed completion prints a stacktrace when I hit tab to execute it) but it does have some cute nuggets:

• it offers an API for installing a completion file (rather than just printing it)
• that generated completion file ends up being a wrapper around your cli tool's own binary, so your shell ends up invoking your binary with special flags when you hit tab and offering completion options based on whatever it prints

that second bit is particularly interesting: it suggests that we can, eg, parse a local taskfile with our regular go taskfile parsing to generate completions on-the-fly

[cgsdev0]

that second bit is particularly interesting: it suggests that we can, eg, parse a local taskfile with our regular go taskfile parsing to generate completions on-the-fly

yeah this is the main feature i had in mind

i will probably start with just writing the completions file, and then we can worry about how to get it installed 👍

[amonks]

sounds cool; lookin' forward to it