Subject: Re: git-testadd: Execute a command with only the staged changes in Git applied

From: Jakub Narębski <[email-masked]>
Date: Thu, 28 Jul 2016 21:31:35 +0200

W dniu 2016-07-28 o 18:56, Øyvind A. Holm pisze:
> On 28 July 2016 at 18:37, Junio C Hamano <[email-masked]> wrote:
>> Øyvind A. Holm <[email-masked]> writes:

>>> This is a script I created some weeks ago, and I've found it to be
>>> immensely useful. Here is a snippet from git-testadd --help:
>>>
>>>   If you have lots of unrelated uncommitted changes in the current
>>>   repository and want to split up the commit, how can you easily
>>>   check if the changes passes the test suite? With all the other
>>>   unrelated changes it can be hard to make sure that only relevant
>>>   changes becomes part of the commit, and that they don't result in
>>>   regressions. This script clones the repository to the directory
>>>   ".testadd.tmp" in the current directory and applies the staged
>>>   chenges there (unless -u/--unmodified or -p/--pristine is
>>>   specified), chdirs to the same relative directory in the clone and
>>>   executes the command specified on the command line there.
>>
>> So in short, this solves the same problem as "git stash --keep" but in
>> a more scalable way, in the sense that "git stash --keep" allows you
>> to instantiate what you have in the index so that your working tree
>> can be used for such a test, but you cannot do anything else while you
>> are waiting for the test to finish, and "testadd" allows you to keep
>> hacking in the working tree while a test runs in its own temporary
>> checkout (and presumably you can have more than one running, which
>> would allow you to scale more)?
> 
> That's correct, the test clone is entirely separated from the working
> copy, and you can keep working while the tests are running in the clone.
> Combined with git-gui and/or "git add -p/git reset -p", it's easy to
> tweak the staged changes until things are ok.

I wonder if using `git worktree` instead of `git clone` (well, local
clone uses hardlinks, so it is not that costly as it looks like) would
be a better solution.
 
> Also, there is a -l/--label option that creates a clone directory with
> the name ".testadd-[LABEL].tmp", so you can have several test clones at
> the same time, all with different staged changes. There is also a
> -r/--ref option that tries to apply the staged changes onto another
> commit, and the command will only run if the apply succeeds. Also, this
> won't create dangling heads like "git stash --keep" does.

Nice.