FR: jj describe --append --message=...

[devurandom]

Is your feature request related to a problem? Please describe.

From a set of scripts, I want to execute commands and record the results in the change description, step by step. I would like for these scripts to be composable and simple (for me to write).

Describe the solution you'd like

It would be convenient if jj describe --append --message=... would exist. It would append a line (or multiple lines) to the existing change description.

Describe alternatives you've considered

Currently, I record the description pieces into a temporary file and execute jj describe --message=$(cat tmpfile) afterwards. This is inconvenient, because I have to pass the temporary file between scripts, and delete it afterwards.

[yuja]

Perhaps, we can add a generic template argument (something like `jj describe --description='description ++ "\nnew description"'), but we don't come up with the syntax.

#3253

For now, you can override the editor to generate description by script.

[devurandom]

Thanks!

After looking at https://jj-vcs.github.io/jj/latest/config/#editor I was able to get this to do what I want with env JJ_EDITOR="${script_dir}"/append-description.sh jj describe --edit and append-description.sh being:

#!/usr/bin/env bash

set -eu
set -o pipefail

outfile="$1"

export NO_COLOR=1

echo -e '\n' >> "${outfile}"
./my/command >> "${outfile}"