scripts: Add convenience script for committing scripted-diffs from a file #16797

When creating a scripted-diff commit, a developer currently needs to:

• Locate and read the Developer Notes on scripted-diffs
• Write a script
• Debug it, possibly over multiple attempts
• Add scripted-diff: to the beginning of the commit message & PR title
• Add the script(s) to the commit body
• Add -BEGIN VERIFY SCRIPT- and -END VERIFY SCRIPT- around the script

I found copying the above text into the editor during git commit to be a manual and repetitive part of building these commits.

This approach allows a simpler workflow for testing, applying, and committing these scripts. A developer can now:

• Create a working script file, e.g. 0.sh
• Run 0.sh to apply the changes, git diff to examine them, and perhaps git checkout to refresh and retry over multiple attempts. When desired, git add the changes.
• Run ./contrib/devtools/commit-scripted-diff 0.sh "docs: Rename X to x globally"

Improvements that could be made to this script:

• Further input validation
• Run test/lint/commit-script-check.sh against the most recent commit(s)
• Use git commit -t <template_file>, which would instead drop the user off in the editor at COMMIT_EDITMSG with pre-filled text. We would need to create template_file on the fly.
• ~Add to Developer Notes and Devtools~
• ~Copyright info~

Feedback appreciated; thank you!

Great idea @ch4ot1c

Thanks. There are some complexities - like these scripts being run on Ubuntu (on Travis), whether or not to use shebang in the file, and the fact that scripted-diffs are run in a subshell.

Concept ACK suggestions:

• add documentation to contrib/devtools/README.md on using this
• refer to the script in the developer notes in the section about scripted diffs

@laanwj Addressed.

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Conflicts

No conflicts as of last run.

Doesn't seem to be much interest; closing.

I personally like this change and would like to see it merged. I think it provides a lot of value for no downside