From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 05 Aug 2026 06:19:43 GMT
Subject: Re: [PATCH] completion: add 'git history' subcommands
Message-ID: <anLV__4THdvugj8f@pks.im>
In-Reply-To: <20260804-history_autocompletion-v1-1-6f7459ffb677@kernel.org>

On Tue, Aug 04, 2026 at 09:56:32PM +0200, Vincent Mailhol wrote:
> Use the parse-options completion helpers for the "git history"
> subcommands and their options. Complete positional arguments as
> revisions, and add coverage for each kind of completion.

Ah, great! I wanted to write shell completion for git-history(1) for a
while but never really found the time to actually do it.

> diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
> index e875787710..f10813c8d7 100644
> --- a/contrib/completion/git-completion.bash
> +++ b/contrib/completion/git-completion.bash
> @@ -2137,6 +2137,30 @@ _git_help ()
>  	fi
>  }
>  
> +_git_history ()
> +{
> +	local subcommands subcommand
> +
> +	__git_resolve_builtins "history"
> +
> +	subcommands="$___git_resolved_builtins"
> +	subcommand="$(__git_find_subcommand "$subcommands")"
> +
> +	if [ -z "$subcommand" ]; then
> +		__gitcomp "$subcommands"
> +		return
> +	fi

Okay. We first try to figure out whether there is any subcommand passed
by the user already. If not, we complete available subcommands.

> +	case "$cur" in
> +	--*)
> +		__gitcomp_builtin "history_$subcommand"
> +		;;
> +	*)
> +		__git_complete_refs
> +		;;
> +	esac
> +}

Otherwise we try to either complete available options if we see a
leading "--", or alternatively we complete references. This works well
for "drop", "fixup" and "reword".

The one command where this falls flat a bit is `git history split`.
While the first non-option argument is indeed a reference, subsequent
arguments are pathspecs. So ideally, we'd notice that we already have a
reference there and, if so, complete file paths.

But that being said, I think this is a good-enough first iteration and a
strict improvement over the status quo -- we don't have to be perfect
right from the start. So if you want to also make that case work then
great, but I won't insist on it.

> diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
> index 9ae3c48ebd..08ecf682ed 100755
> --- a/t/t9902-completion.sh
> +++ b/t/t9902-completion.sh
> @@ -3107,6 +3107,23 @@ test_expect_success 'git clone --config= - value' '
>  	EOF
>  '
>  
> +test_expect_success 'git history subcommands' '
> +	test_completion "git history " <<-\EOF
> +	drop Z
> +	fixup Z
> +	reword Z
> +	split Z
> +	EOF
> +'

This will cause conflicts with "seen", as there's a new upcoming
"squash" command that's currently cooking there. That's fine though,
nothing you can do about that.

Thanks!

Patrick