Inline command substitution

[nirmalnirav]

Respected Mr. Pope,
please accept my gratitude and then greetings. I am humbled that I have a chance to write you.

Problem Statement

• On the command line it is possible to use the command substitution.
• Error upon the command :G diff --stat $(G merge-base --fork-point main_branch)

Error

fatal: ambiguous argument '$(G': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

Explanation

• We use BitBucket to collaborate at work. I want to avoid it and hence started looking for ways to work exclusive from terminal.
• I came across a way to find the commit hash at which a feature_branch was created: git merge-base --fork-point main_branch.
• Currently I would like to use that command and replace its output inline within another command: G diff --stat $(G some_command).
• That way I can navigate to the file(s) of interest using the vim normal mode command gf from the file list.

Extension

If possible, please break the feature request in to smaller tasks along with a short pointer to the code section and assign them to me. I would gladly work on them and hence collaborate with you. I have never done any serious vim scripting and therefore would be a good learning experience.

Thank you for your time!

[cjrh]

An option is to build your own using execute. I'm also using merge-base in a similar way:

:execute 'Git diff ' . system('git merge-base --fork-point upstream/main')[0:-2]

The commit hash coming from merge-base has a trailing newline, which the [0:-2] removes.

[nirmalnirav]

Hello @cjrh ,
it works! Thanks for the hint. 👍
I could not find the meaning of a single dot . between diff ' and system in the vim help. Could you please explain/ hint me to the meaning of the dot?
Thanks!

[cjrh]

It's just concatenation, no big mystery 😄

…

On Thu, 1 Aug 2024, 4:31 pm nirmalnirav, ***@***.***> wrote: Hello @cjrh <https://github.com/cjrh> , it works! Thanks for the hint. 👍 I could not find the meaning of a single dot . between diff ' and system in the vim help. Could you please explain/ hint me to the meaning of the dot? Thanks! — Reply to this email directly, view it on GitHub <#2319 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADVJC234AZWLWIY2LMSLCDZPJBE5AVCNFSM6AAAAABKMXDTI2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENRTGIZDONRSGE> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[tpope]

Fugitive does provide an API for that system() call that's a bit more robust:

:execute 'Git diff ' . FugitiveExecute(['merge-base', '--fork-point', 'upstream/main']).stdout[0]

[nirmalnirav]

Wonderful! Thanks for the comment! I would like to close this ticket as solved.

[cjrh]

@nirmalnirav You can close it yourself 😄