Re: [PATCH 1/2] sparse-checkout: custom tab completion tests

[Elijah Newren <newren@gmail.com>]

On Fri, Dec 31, 2021 at 2:30 AM Derrick Stolee <stolee@gmail.com> wrote:
>
> On 12/30/2021 11:19 AM, Lessley Dennington wrote:
> > On 12/30/21 7:43 AM, Derrick Stolee wrote:
>
> >>> +    (
> >>> +        cd sparse-checkout &&
> >>> +        test_completion "git sparse-checkout set f" <<-\EOF
> >>> +        folder1 Z
> >>> +        folder1/0 Z
> >>> +        folder1/0/1 Z
> >>> +        folder2 Z
> >>> +        folder2/0 Z
> >>> +        folder3 Z
> >>
> >> This tab-completion doing a full directory walk seems like it could
> >> be expensive for a large repository, but I suppose it is the only way
> >> to allow the following sequence:
> >>
> >>     fol<tab> -> folder
> >>     folder1/<tab> -> folder1/0
> >>     folder1/0/<tab> -> folder1/0/1
> >>
> >> (Hopefully that makes sense.)
> >>
> > Yes, it does.
> >> It would be more efficient to only go one level deep at a time, but
> >> that might not be possible with the tab completion mechanisms.
> >>
> > When you say one level deep, do you mean that from the sparse-checkout
> > directory, tab completion would only show the following?
> >
> >     folder1
> >     folder2
> >     folder3
>
> That's what I mean by one level deep at a time, but I also am not
> sure that that is the correct functionality. I would leave the full
> expansion as you have now as the design.

I think one level at a time is better and is the optimal design.  By
way of comparison, note that if I do the following:

mkdir tmp
cd tmp
mkdir -p a/b/c/d
touch a/b/c/d/e
cd <TAB>

I do not see a/b/c/d as the completion, I only get "a/" as the
completion.  If I hit tab again, then I get "a/b/".  Tab again, and I
get "a/b/c/".

I don't think normal tab completion recursively checks directories, so
it'd be better for us to not do so with git either.  However, if it's
hard to avoid automatically completing just a directory at a time,
then I think a fair first cut is completing to full depths, but call
it out as something we'd like to fix in the commit message.