Re: Unexpected behavior with the rev-parse operation

[Eric Sunshine <sunshine@sunshineco.com>]

On Mon, Apr 15, 2024 at 9:58 AM Toru Okugawa <castor.4bit@gmail.com> wrote:
> I have encountered some unexpected behavior with the rev-parse operation.
> ---
> $ ls -a
> .  ..
> $ git rev-parse --is-inside-work-tree
> fatal: not a git repository (or any of the parent directories): .git
>
> What did you expect to happen? (Expected behavior)
>
> If the current working directory is outside the work tree, the
> documentation says that `git rev-parse --is-inside-work-tree` will
> output false.
> https://git-scm.com/docs/git-rev-parse#Documentation/git-rev-parse.txt---is-inside-work-tree

I think this is working as intended, but the documentation is lacking
or misleading. With very few exceptions[1], `git rev-parse` expects to
be run either within a Git working tree or within a Git repository
(i.e. the .git/ directory or a bare repository). Options such as
--is-inside-work-tree, --is-bare-repository, etc. are meant to report
upon aspects of the worktree or repository in which the command is
invoked.

Looking at the source code for `git rev-parse`, it does appear that it
has explicit support for the case of checking whether or not the
current directory is a Git worktree or repository. The way to do that
is to run `git rev-parse` without any arguments. However, even in that
case, it will print the "fatal: not a git repository" error. This
means it is your responsibility, as a script writer, to suppress or
capture the error message (whichever is appropriate for your case).
For instance:

    if test git rev-parse >/dev/null 2>&1
    then
        echo "in a Git directory or repository"
    else
        echo "not in a Git directory or repository"
    fi

[1]: --sh-quote, --parse-opt, --local-env-vars, --resolve-git-dir